jiyasa

iTrader: (1)

I have a 91 3.1L v6 firebird and lately the engine has been idling pretty high, the car acts like it's going to die when it isn't being given gas. I was in mid-turn and the engine died and the CEL came on and started back up. It's been doing this awhile, as I drove it the rest of the way home it smelled like fireworks so I'm a bit concerned. Any thoughts guys?

92rsvortec350

iTrader: (8)

could be a hand full of things you need to pull the code that's stored and see what it says so you know where to start.

jiyasa

iTrader: (1)

Well I just did the hairpin trick and the CEL does not flash any codes, it blinks once and stays on solid. I haven't driven the car in a little while but when I start it up I smell gas.

92rsvortec350

iTrader: (8)

can you dive it to a auto parts store and let them pull the codes they will do it for free and will help a lot.

jiyasa

iTrader: (1)

If I kept giving it gas I could probably get it to an autozone or something, the only thing about that is our third gens have obd1 ecm's and most code readers at the auto parts stores only read obd2 but I suppose it can't hurt to swing by and check. I believe whatever this problem is is fuel related because at one time I used tunerpro rt and it said it was running sort of rich. The car sputters when it isn't being given gas, as long as I keep my foot on the throttle it keeps it running. I have two new injectors and four remanufactured ones so I'll probably start with those four and check the oxygen sensor and move from there. This car had a code 33 at one time and I'm guessing changing out the map sensor and fuel injectors helped then but I don't think all my fuel problems are sorted out yet. These are the tunerpro readouts as of last year:

error- fuel pump voltage low
knock count at 07
MAP fluctuates from 60 to 80 when engine at high rpm
block learn multiplayer went red at 140
target air/fuel ratio went red at 12.00
low coolant/corrosivity sensor low at 5.00
MAT at orange between 55.00 and 75.00
EGR VALVE 1 2 3 are off need to check if normal

92rsvortec350

iTrader: (8)

You wouldn't happen to have a fuel pressure gauge would you?
I would check fuel pressure just to make sure its right.
I have had similar problems before and it was the coolant temp sensor the one for the ecm not the gauge wouldn't hurt to check the throttle position sensor also but hopefully you can get some codes pulled and see where that points.

southbay08

"I have two new injectors and four remanufactured ones so I'll probably start with those four and check the oxygen sensor and move from there."

It really doesn't make a difference if you combined new and reman injectors. Are they the same brand and part number? The spray pattern needs to be the same.

jiyasa

iTrader: (1)

It really doesn't make a difference if you combined new and reman injectors. Are they the same brand and part number? The spray pattern needs to be the same.[/quote]

To be honest I'm not altogether sure, I had a shop install two new ones but I have no idea what brand or spray pattern they bought. I bought the other remanufactured ones from you guys. I need to check that too.

Vortec, I think I may have a fuel pressure gauge. I need to get ahold of a code reader. That would probably help too.

southbay08

did you start experiencing the problem after you installed the injectors?
If you have a chance get the numbers off of the injectors and send them to me. I will be able to tell you if they are the same

sailtexas186548

iTrader: (2)

is your gas tank full?

jiyasa

iTrader: (1)

Southbay, I'll pull all of them soon and get the parts numbers for you. I appreciate it.

Sailtexas, no my gas tank is on an eighth of a tank. I admit the car has sat for a little while and lately I've been trying to keep it running every so often. Had to use a slow charger on it.

sailtexas186548

iTrader: (2)

Fill it up to 1/2 a tank with fresh gas, I bet your running out of gas in the corners. My car does that sometmes when it's low on gas.

That may be the reason that it's having fuel delivery issues (or symptoms) as well

jiyasa

iTrader: (1)

Okay, it may need some fresh gas. It's had the same gas in the tank for like two months or so.

thatoneguy5x

you ever figure out this problem?? im having the same issues. even with a full tank, fairly new coolant temp sensor and 02 sensor. just started happening 3 days ago after driving on some winding roads. my car turned off mid turn. also a 3.1

jiyasa

iTrader: (1)

Don't hold me to it but I think with these cars the power steering has something to do with this issue. When you turn the wheel it puts a strain on the engine. Anytime it's ever happened to me I just pulled over and it would always start right back up though. When you get about mid-turn the wheel tightens up and the car dies and the CEL comes on doesn't it? I'm still going to check for vacuum leaks and pull the injectors to find the part numbers for southbay. I'll let you know if I find anything, thatoneguy.

92crimsonRS

my old 92 rs had a switch on the pressure line of the powersteering. it was there to help with the idle when turning. i would check it. mine was leaking around the plug and would every week or so lose connection and die while turning.

ASE doc

Power steering does put load on the engine in turns and these cars did not have any direct compensation for this as they did not use a power steering pressure switch like later vehicles did. They rely on the engine to support the load on it's own with the PCM using the IAC to maintain idle speed. Unfortunately, you are right that there is little chance that any parts store is going to have a scan tool that will read codes on your car. Also unfortunate is that OBDI self diagnostics was very crude and alot can go wrong without ever setting a code. If you flashed codes and nothing came up, it most likely means that no fault code has been stored. While no codes may be stored, a compatible scan tool, that actually reads ECM data, could be very helpful.

From the bit of tuner pro data that you listed, I can see that the engine wasn't running rich but rather lean. Block learn runs 128 normally. Higher is lean(adding fuel), lower is rich(removing fuel). Block learn is long term fuel correction and goes high or low in response to Integrator which is short term fuel correction. The high idle speed with loss of idle torque(stalling under load with you foot off the pedal) with high Block learn points to a vacuum leak.

With a scan tool you could drive the car in road test mode and watch to see if Block learn and Integrator return to normal as you drive(as load increases). This points to a vacuum leak. If fuel trims stay lean as you drive, this would point to a fueling issue such as injectors, MAP senor, fuel pressure.

ASE doc

And then again, some may have a PS pressure switch.

jiyasa

iTrader: (1)

Hi Ase Doc, thank you for the info! I'm willing to bet that my bird doesn't have the PS pressure switch but hypothetically, if it did where would this switch be located?

Yesterday I had a little help from my brother, he crawled under the car to listen to the inner tie rod ends to see if they were shot and as I turned the wheel back and forth in the car I noticed that when the wheel was turned as far as it would go (left or right) the engine would strain a little unless I turned the wheel back. If it's alright with you since you seem to be more knowledgeable in this department than I am, I am going to video capture my car hooked up to tunerpro as I'm driving the car and post it on here or send it to you. Would that be okay?

jiyasa

iTrader: (1)

I should have specified that I am going to video capture my laptop screen with tunerpro rt running as my car is connected to it and being driven in real time and post the video results.

92rsvortec350

iTrader: (8)

The ps pressure is located on one of the power steering lines it tells the ecm to idle up a little to compensate for the load, I thought that may be it but after reading more of your problems it seems that the car is not running as it should really anytime.

ASE doc

Please do post the video on this thread. You can PM it to me if you like but I am way busy and may not get back to this right away. As you might be able to tell, there are many on this forum who are very knowledgeable. If I don't get back right away, others may have good information for you.

My best advice is to say that when I diagnose any driveability issue without fault codes, depending on the symptoms, I start by watching fuel trims on a road test. Then I verify fuel pressure, spark KV, and if it's warranted, compression. Making sure that the engine is mechanically sound and that the ignition is healthy allows us to focus on the fuel and air systems. Ask yourself also, does the engine idle smooth? Does it run okay down the road? Try to pinpoint when the problem is actually present. This is a big clue to what the problem might be. Then we just need to look at the evidence, in your case I'm thinking lean condition, and pinpoint the cause. Remember, lean at idle is most likely air leak, lean under load is generally fuel supply or fuel control.

There are issues that fall outside this diagnostic regimen. Sticking EGR, restricted catalyst. These can require other tests to verify. You symptoms don't sound like either of these, but be sure that your EGR isn't stuck part way open anyway. It sounds like you have the three solenoid early style electric EGR valve. One of the three valves may be pinned open by a chunk of carbon.

thatoneguy5x

im kinda leaning towards vacuum. my car always starts right away even after the 2 times it stalled from this problem so I doubt its the fuel system I could be wrong. the fuel filter is only about 2-3k miles old as well
at first I thought maybe it was a tear in my brake booster hose cause it only happened when I was slowing down(made sense in my head) but after carefully checking the hose it was all good and intact. the car always runs good otherwise.
I don't have my vacuum ball hooked up but im thinking it might help out a bit to ease the strain on the engine and get the vacuum where it needs to be. (correct me if im wrong but it is a vacuum reservoir?)

i just ordered an intake gasket set from o'reilly just waiting it to get to the store. also gonna rent out the fuel pressure gauge just to rule out any leaks in the fuel system. when I have it all apart im gonna check the resistance of the injectors. im pretty determined to get this all figured out!!

jiyasa

iTrader: (1)

I appreciate all your info and help asedoc. Today I got out there and squeezed some of the vacuum hoses and didn't really hear any change in idle but I do remember the car groaned some when I squeezed one of the hoses ...idk. I'm a little leery about using flammable chemicals (brake cleaner and the like) to check for vacuum leaks so I'm not altogether sure how to go about this. I do have a vacuum gauge, may use that. Tomorrow I will run tunerpro and post the video on here. I'll pull the egr valve and clean it up and put it back in and see if that helps. Usually when the car sits for awhile and is cold, the idle surges pretty high while in park (2-2.5K) but after it warms up it runs pretty smoothly (700-800 range). I've noticed as soon as I put it into drive the idle drops immediately. It runs fine most times going in a straight line or when my foot is on the gas. I noticed a couple years ago that at stop lights in the summer and in warmer weather the car would stall more often, especially in mid-turn. It would start by sputtering for a little bit, sometimes the idle would pick back up to normal. Other times the car would stall and start right back up. The stalling problem seems to be intermittent like thatoneguy5x has.

ASE doc

I have replaced ECMs due to the quad driver for the IAC failing. You need a lab scope to verify this type of failure. We have an old Thexton IAC tester that allows us to quickly verify the IAC is good or bad. I use my lab scope to watch the control signal. The GM IAC solenoid is a two coil stepper motor(coil A and coil B). In order to open or close the valve(raise or lower idle), the ECM powers each coil on and off in tandem. As each coil is powered on, it moves the valve one step. By switching the coils on and off, the ECM opens or closes the valve. The signal to each coil should look like an on/off digital signal.

You can use a 12 volt test light for a quick check of the signal, but it won't tell you absolutely whether the signal is what it should be. With a scan tool, tuner pro also if you can decifer the data pids, you can see desired idle(some cars), actual RPM, and IAC steps or count. High count means the ECM is opening, or trying to open the the IAC valve. If actual idle doesn't follow desired idle pretty closely, there is an idle control issue. One way to quickly test the IAC is to simply turn the car off, then turn the ignition back on, but don't start the engine. Now, disconnect the IAC and look at the pintle height compared to the depth of the valve bore. The pintle should be retracted almost all the way for engine start. You can also test idle control by switching the AC on and off. The idle should jump up slightly as the ECM sees the compressor on signal.

Brake cleaner is not that flammable. I use it all the time for both air leak testing and quick cleaning before disassembly of engine components. I have never had it catch fire ever in decades of using it this way. Used to use carb cleaner back in the day, it is a bit more flammable. Ask me how I know this. Spray the brake cleaner liberally around manifold seams and hose ends. If you get it anywhere around the throttle opening, you will hear a response. Double check to make sure you aren't being fooled.

Practice using tuner pro while you drive and take note of the data you see. Oh, and please don't crash watching the screen. It can seem like alot of information and it may not all make sense but you can figure out what it all means here by asking questions and posting your results. This insight into the workings of the ECM is the best way to figure out a problem. It is where I start every diagnosis. As you come to understand what all the pids are, you will catch things that don't look right. These are clues for you to follow and will likely lead you to the problem. I love my scan tool.

jiyasa

iTrader: (1)

Okay, I ran tunerpro on my car and filmed it. I drove the car for about fifteen minutes and when I pulled it in it smelled like firecrackers so that was weird. I posted the video on a cloud site, anyone who is willing to watch it here's the log-in info:

http://mydrive.ch/en

Username: 91firebird@pigs3differentones
Password: knightrider

Let me know what you think, I'd appreciate any feedback or thoughts anyone can give me. Thanks!

jiyasa

iTrader: (1)

Anyone?

ASE doc

I tried to watch the video but I can't get it to play. Just the windows media player effects garbage. Sorry I didn't get back to you sooner. I've been focused on my car and busy at work. The firecracker/sulfur smell is your catalyst processing an excessive amount of hydrocarbons. You'll get that smell anytime an engine is misfiring, running rich or lean, or otherwise dumping alot of unburned fuel down the exhaust. This will eventually lead to destruction of the catalytic converter if you continue to drive it this way.

One thing I have dealt with on the 3.1s is timing chain wear. If you can't find any air leaks at the intake or other cause of poor running, you can check timing chain wear using a timing light. While watching timing with the timing light, snap the throttle and watch for the timing mark to jump up and come smoothly back to where it started as the engine returns to idle. If it does this, the chain is okay. If the timing mark toggles back and forth after you release the throttle, the chain is likely worn and loose. This can really mess with engine performance as the ECM tries to control timing that is constantly changing on it's own. Injectors are another big problem. At GM, we had alot of trouble also with the throttle bodies. The early design with the bell crank throttle linkage put alot of stress on the throttle shaft. The shaft bores wear until it no longer returns to idle consistently. The inconsistent base TPS reading causes the ECM to lose it's base idle adaptive and the car will stall under load at idle. I've also seen other strange drivability complaints caused by this same thing. GM later changed the TB design and the problem dissipated but I think your 91 might fall into the early category.

To check for worn throttle shaft bores, using your tuner pro with the key on engine off, take note of the TPS voltage. Then, open and close the throttle and note TPS voltage again. Do this several times, watching for the TPS value to change slightly from one time to the next. This tells you that the shaft bores are worn and affecting base TPS value. You will need to replace the TB.

jiyasa

iTrader: (1)

It's okay, I understand. I'm sorry the video didn't play right, I uploaded it on youtube. I noticed that the car showed an IAC Malfunction (Code 35) at the bottom of the screen so I'll let you be the judge on that one. Today I'm going into town to get a can of brake lean and clean out the TB and IAC and hopefully that might help. Again, I really appreciate all your help. Let me know what you think. Here's the video:

http://www.youtube.com/watch?v=jThCU...ature=youtu.be

Eric-86sc

iTrader: (18)

I had the same problem for a while in my 92 3.1 firebird. The car would stall on hard left turns an had an intermittent hard start issue. What it ended up being was a bad fuel pressure regulator diaphragm. To check this pull the vacuum line of the regulator with the car running, if it drips gas theres your problem.

jiyasa

iTrader: (1)

Hi Eric, yeah mine does exactly like that. I had actually bought a fuel pressure regulator but never had it installed. It's under the plenum close to the fuel rail am I right?

Eric-86sc

iTrader: (18)

Yes, you will see a vacuum line that runs under the front of the intake near the throttle body. That black dome thing the vacuum line connects to is the fpr. Pull it off with the car running for a while and see if gas drips. Car ran a whole lot better once I figured my problem out.

jiyasa

iTrader: (1)

Okay, I'll have to check that out. Lately the weather here is too cold but hopefully once it warms up I'll have to look into that. At this point I'm willing to try anything, thank you Eric!

Eric-86sc

iTrader: (18)

No problem I hope I was able to help you. Keep us updated so we can see if any of our suggestions were correct.

jiyasa

iTrader: (1)

I sure will, thank you again!

ASE doc

I always have to question scan tool data that looks unrealistic, but there are a few things I see that could point to a problem. One is Batt voltage. That data PID is simply the ECM's monitor of its own constant Batt power supply circuit through the ECM/Fuel pump fuse. This PID should always read close to actual battery voltage. I saw it drop to 0.00 at the end of the video. This could be a sign of either a poor connection at the ECM/FP fuse or a poor connection somewhere else in that circuit.

I also saw that the TPS voltage and the ECM reported TPS percentage are way off from each other. 0% TPS should be at about .6 volts. 100% TPS should be at about 4.5 volts. This can vary according to the ECM's learned TPS values. The TPS on your 92 is not adjustable but rather the ECM simply records minimum TPS at each key on event, before the engine is started. This is the ECM's minimum TPS voltage. That voltage reading becomes the ECM's minimum TPS, or 0% TPS. The fact that the ECM's TPS value is so far off is a sign that either you've had your foot on the pedal when you turn the key on, or that the TPS voltage signal to the ECM has been affected somehow. Remember also what I said before about throttle shaft wear. TPS voltage and percentage values that don't jive is one sign of this type of failure. Use the test that I detailed for that.


Start first by checking the ECM/FP fuse. It should be in a black plastic in line fuse holder close to the battery. Be sure the wire to the fuse from the battery is okay and that the fuse isn't heat damaged from poor connection. If it is you'll need to replace it and repair or replace the fuse holder. Then go to the ECM and check all terminals in both connectors for corrosion or damage. Water intrusion in these units has never been a real issue due to the ideal mounting location behind the RH dash panel(where you would think a glove box might be). Still, check the ECM case for signs of water or other damage. Also, check the ECM/IGN fuse in the fuse panel for good connection and condition.

Next, check the ECM grounds which are located at the rear of both cylinder heads. These are difficult to get at but using a 9/16" wrench, you can generally get on the bolt heads. Loosen and tighten the bolts while working the wire terminals back and forth with the bolt loose to clean the connections. Once you've verified good grounds and power connections to the ECM, use tuner pro, assuming it has the function, to perform the idle learn procedure. This will reset minimum TPS values as well as IAC. This may or may not solve your problem but it's something you need to do.

jiyasa

iTrader: (1)

Hi ASEdoc, when I made that video I tried to get the sound to work to give a sense of when the engine was started and turned off. When the video started for about half a minute I left the car in auxiliary for a bit then started it and I think when you saw the actual battery voltage drop to 0 was when I turned the car off (I still had the video recording when I turned the car off).

It's been so cold here getting below freezing I haven't had much of a chance to do much to the car but I did what you said about turning the AC on and then off again to see if the idle would change under the strain of the compressor. The idle never once hitched or spiked in anyway when I did that. I had trouble with a code 33 a couple of years ago and changed out my MAP sensor and all six injectors and for some odd reason that seemed to have taken care of the problem at everyone's advice that I go ahead and replace the old injectors. So I may take your advice and just replace the whole TB intake and see if that helps. When the weather warms up I will test some of the things you've mentioned.

jiyasa

iTrader: (1)

Speaking of which, does anyone know where I might find a new throttle body assembly? I'm having a hard time finding one.

ASE doc

A good used part is all you'll find. The OEM dropped support for that motor long ago and because the design was only used a few years, the aftermarket never picked it up. Don't just throw a replacement part on it though until you've determined the TB is bad. The shaft bores can also be reamed and rebushed by good carb shop.

jiyasa

iTrader: (1)

Okay, I really appreciate all your help. Once the weather gets a tad bit warmer I'll get out there and check all the things you've mentioned. I'll just be happy when it gets above freezing here! As I'm sure you've gathered I'm not very mechanically savvy but if I can learn the location of things and how to get to them I do alright. I actually found replacement TB's on ebay but they seem to be custom parts that are geared toward performance so I'm not altogether sure they would work on my car.

ASE doc

As I said earlier, the BATT V POD is constant battery voltage to the ECM. It shouldn't drop to zero. With a factory or equivalent scan tool, that PID WILL always read battery voltage whenever the ECM is communicating data. As I also said though, I tend to be suspicious of scan data that doesn't make sense. Some scan tools do behave strangely. Still, it's worth it do verify power supply too the ECM. Something else is the battery itself and the charging system. Make sure that system voltage dropping too low at idle.

jiyasa

iTrader: (1)

Hi ASE, I plan on going back over every post and checking everything you've mentioned on my car. I had bought my battery back in late 09 and I admit I let it sit without being driven for a little bit and had to use a slow charger to get it jumped again. I don't know if that would play any part in the voltage to the ECM or not but I thoroughly plan on checking everything you've pointed out, timing chain included, IAC, TBI, everything. What I may do is take another video of my dash's gauges as I'm running the car from a cold start(notably the voltage gauge) and maybe get your opinion on that. Would other scan tool/product would you recommend that might work better?

ASE doc

The tuner pro should be fine. You just need to be aware of how it interacts with the ECM. Different scan tools may behave differently. It can be tricky to be sure if something strange you see is the ECM or just the scan tool. The Snap On MT2500 and its later versions is what I'm most familiar with. It functions very much like the GM Tech I and Tech II. If you did decide to go with Snap On, the old MT2500 "brick" has long been discontinued and there were millions made. They are out there on craigslist and ebay for cheap. While tools like my new Modis Ultra with its large LCD touch screen are super nice to use, the old units actually have all the same functionality on the early GMs and you can find one for $300.

I hope I haven't overloaded you with information. the things I have listed are just things that should be looked at once the most likely suspects have been eliminated. The more common causes of your kind of symptom are of course injectors, vacuum leak, ignition timing, and possibly the fuel pressure regulator. Generally, when the regulator diaphram ruptures, the added fuel drawn into the engine will cause it to run rich, which will cause integrator to lower(removing fuel). It's hard sometimes to distinguish rich running from lean running as both will cause rough idle. A lean idle has more tendency to surge, while a rich idle may lope if its rich enough. Watching fuel trims is the best way to know what's really going on.

jiyasa

iTrader: (1)

Well I want you to know that I greatly appreciate all your help and advice, I've resisted putting off getting my hands dirty and handed it off to a shade tree mechanic most times who would guess or fix something that didn't need to be fixed. The last time I took my car to the mechanic I came back two weeks later and the battery was dead and all of my taillight bulbs were burnt out. Thank you for all your help ASE. I know without seeing my car in front of you it's hard to know what to say so what could I do to maybe see the fuel trims? Can I see them in tunerpro or will I need something else? Just learning as I go.

ASE doc

Fuel trims are Integrator(short term) and Block Learn(long term) I was watching them change in your video. It's normal for them to go low when the engine is cold. They are pulling out some fuel due to the warm up fuel mixture being rich. Once the engine reaches 170+ degrees, the long term fuel trim should stay close to 128. Don't ask why GM designed the software this way, but 128 is neutral. Above that is added fuel (engine is lean and the ECM is adding fuel to compensate), below 128 is rich(ECM pulling out fuel). Short term will change constantly as the vehicle is driven.

A short course on fuel trim logic: The O2 sensor cycles from .200-.800 milivolts in response to oxygen content in the exhaust. Short term fuel trim changes in response to trends in O2 voltage. For example, if the engine is running rich, O2 voltage will tend to be closer to .800 milivolts than to .200 milivolts. Short term FT will then drop below 128 as fuel is pulled out top correct for the rich condition. Long term fuel trim changes in response to short term fuel trim the same way that short term FT responds to O2 voltage. If short term FT tends to run below 128, Long term FT will drop below 128 to compensate. Long term FT is the ECM's correction for a "long term" rich or lean condition. Long term FT tells us if the engine is actually running lean or rich.

The fuel trim program also has fuel trim cells which are just squares on a grid. The grid covers all driving conditions from idle in Park to full throttle acceleration. By being aware of what FT cell the ECM is in when you see rich or lean fuel trims, you can see if and when the engine is running lean. Is it lean at idle? Is it lean under load? The scan tool shows the fuel trim cell in data. It's the "BLM cell" PID on the early systems.

thatoneguy5x

ok I have some results for you guys! after doing an full intake manifold gasket change, distributor O ring, injector O rings, and cleaning up all the gunk out of the manifolds (about $30 total + a couple hours of my time) my car runs 99% better.
I didn't remember to check the timing before I pulled the distributor but when I was done I set it back to 10* idles smooth and drives great. ALSO I found a vacuum leak on my brake booster hose right where it connects to the booster. the hose isn't cracked or anything but its just old and isn't fitting the nipple tightly I zip tied it for now until I can go get a new one.
I was having the same issues as you. it might not be your exact problem but it really helped me. good luck!

jiyasa

iTrader: (1)

Sorry for the slow response guys, I appreciate all the feedback. The weather is warming up here a little so I plan on getting outside and checking some of these things. I'll give an update as soon as possible. And thank you for the update thatoneguy, I'll check that out as well on mine! I'll likely be back with another video or two.

jiyasa

iTrader: (1)

Update: It was warmer today here, in mid-high 60's so I drove my car to the gas station and put some gas in as I was cutting the wheel as far as it would go the engine died. Started right back up and drove to my neighbor's house to drop it off to have him work on my suspension and with it coasting downhill with the wheel straight it died again. I've noticed that it will still stall without the wheel turned, having the wheel turned as far as it will go just seems to exacerbate it along with warmer weather. It dies more often in warmer weather. I know this isn't a result of running any test on the car, just moreso an observation I made today.

ASE doc

It's just low idle torque. The engine isn't producing enough torque at idle to stay running consistently. When you increase load by deadheading the PS pump, the engine can't carry the load and stalls right away. Is this a manual transmission car or automatic? When you say coasting, was the trans in neutral or in drive? Does the engine idle rough? I would assume it does.

Any of the possible causes mentioned above would apply here. A lean condition is simply the engine not getting enough fuel for the amount of air it is displacing. That lack of fuel causes low torque.

jiyasa

iTrader: (1)

Hi ASE, the car is an automatic. When it was coasting, the transmission was in drive rolling downhill without any pressure on the throttle whatsoever. When I started the car that day on a cold start (hadn't been driven in like a week) it started up and gradually surged up to about 2k rpm until I put it in drive and then the rpm dropped some (around 1k-1.2k), still high though. It only seems to sputter and die while the trans is in drive, in park it idles high. Can actually sometimes hear it from inside my house.