Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
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i have an 87 305 tpi with only 45k miles on it, hasnt really been driven for about 3 years
it has a new alternator and spark plugs, but when i start the car, it dies immediately if i dont give it a little gas
then once it has started, it doesnt run good at all until it has warmed up. i press the gas, but the rpm's dont increase and the car doesnt accelerate, but then if i leave the gas pedal depressed for a few seconds, it "catches" and accelerates fine
the car runs perfectly once it is warm, anyone know what could be wrong?
I could offer a lot of guesses, but there's a good chance that there is either an error code or another symptom that will narrow the field of possibilities. Have you scanned for error codes?
what exactly is "scanning for error codes?"
i dont think the computer actually recognizes any kind of error since the service engine soon light has not come on, but i really have no idea
I had this same problem. First it was starting, it felt like I had carbs and I had to give it more gas right after starting. I really had to mash the gas down at first, then it wouldt idle smoothly for 10 minutes. It was right after I installed the flowmaster american thunder exhaust. Then it started to pour blue smoke on startup. Then I blew the motor. You really need to get this problem looked at, and make sure you are always using premium gasoline.
Hope that helps, and im sorry to give the bad news.
blue smoke is burning oil, adding a cat back exhaust system should in no way cause an oil leak.. makes no sense.. could be a coating of oil burning off that was applied to prevent it from rusting.. not sure on that.. exhaust work should in no way cause an engine to suddenly start burning oil.....
Rsn as far as your problems a few questions... you said its been sitting for several years.. have you done a basic tune up? while your at it I would suggest cleaning the throttle body and IAC passages.
not a complete tune up
only done spark plugs and the IAC thing
also ive looked in the throttle body and it looks fine, nothing clogging it anywhere and it seems smooth and normal
any other suggestions?
you should definately take it to a shop to find out what the real problem is and i dont believe there is anyway possible that the exhaust could cause it to smoke more ...........once you run the car for more than 5 min most of the packaging oil should be burnt off the new pipes .....id give it a complete tuneup before jumpin the gun too much thou and see how that helps...
I might be way off but how about the fuel filter? my car was running rough after being in storage for 2 years and after a good tune up (inc fuel filter) its like another car.
i think i actually have a new fuel filter sitting around somewhere so i'll try that
im just curious about one thing: why would a bad fuel filter cause it to be really rough idling when first started, only to then run fine once warm? if it was bad, wouldnt it always run rough?
The oil smoke on startup is a symptom of failing valve stem oil seals. If the engine sat for 3 years without much running, it is entirely possible that the valves' umbrella seals and 'O' rings have dried, cracked, and are useless. My '86 TA has 48K miles nad has had oil smoke on startup since about 16K miles. I don't lose sleep over it, and will convert to positive oil seals if/when I ever get the heads off it for whatever reason. In the interim, I just let it enjoy the extra upper cylinder lubrication on cold startup.
The operational problems you are experiencing may be due in part to fuel that is three years old. I'd suggest refreshing the fuel with the lowest octane (most volative) fuel you can get and allow time for the fuel to blend and get to the fuel rails. If you're lucky, you won't have plugged the injector inlet screens with junk before then.
As for the error codes, you may or may not have a "Check Engine" light on your dash that stays on after the engine is started, or has been on during engine run at any time. If that is the case, the ECM should have a stored error code, which may provide clues as to the cause of the problem(s). You can retrieve these error codes rather easily.
First, you'll need to acquire a GM OBD I ECM Diagnostic Trouble Code Retrieval Tool (commonly known as a paper clip to TGO members). Form this wire into a ‘U' shape.
With the engine and ignition turned off, locate the ALDL connector under the dash, just to the right of the steering wheel in the driver's foot well area on some models, and on the left on others, depending on the make and year. There should be a small rectangular cover over the access hole in the lower dash trim, or at least was when the car was delivered.
Insert a tool as described above (paper clip) into the 'A' and 'B' terminals on the ALDL connector:
WITHOUT STARTING the engine, turn the ignition to the "RUN" position. Watch the Malfunction Indicator Lamp (MIL) - it will begin to flash. This is also commonly called the "Service Engine Soon" or "SES" lamp. The first code will flash three times, and will usually be a code '12'. This is encoded by one flash of the lamp, a brief pause, then two successive flashes of the lamp. Each code will repeat three times, so you should see a "Code 12" flash three times. Any other error codes will follow in numerical order, and each code should flash three times. After all codes have been displayed three times, the "Code 12" will again flash three times, then all other codes will follow as described earlier. This cycle will continue until the jumper is removed or the ignition is turned off.
After you have made a note of all error codes, turn off the ignition and remove the jumper immediately. If you forget to remove the jumper and attempt to start the engine with it in place, you could damage the ECM. For this reason you should remove it immediately.
Once you have a note of all error codes, check this file for the decoding:
If you have no stored error codes, you should start by checking the fuel rail pressure with the engine running and again after shutting the engine off. This will help determine if the injectors are leaking, and/or if the fuel pressure regulator is leaking or not holding correct fuel pressure, and may indicate fuel pump and/or filter problems.
new fuel filter yesterday, still having the same problem
havent had time to scan for codes yet but hopefully i will be able to soon
any more guesses anyone?
thanks
You mentioned you changed the spark plugs. Are you sure the wires are on correctly. Not meant as a dig at your mechanical skills or anything. But when I got my Headers put on the guy screwed up the wires and it ran just like you are describing. Just a thought.
I would strongly recommend NOT taking the car to a dealer, or for that matter, another repair shop.
This is due to the fact that repair shops are not motivated to diagnose a problem, they are motivated to change parts until a problem goes away.
Think about it, they can spend 2 hours poring over everything and only earn shop time, meanwhile having no tangible results to justify their time, or they can spend 2 hours tossing on new parts (with highly inflated costs) and get more money, as well as justify the time spent.
If you doubt this, read a dealership chassis service manual for a poor running condition. It reads, "change this part, this part, this part, this part, and this part. Check to see if problem persists. Now change this part, this part, this part, this part and this part. "
Your money and time will be much better spent by you spending the time to figure where the issue lies, and then making the decision wether to fix it yourself or have it serviced.
thanks guys i will check the spark plug wires
just curious though...if hte plug wires were going to the wrong plugs, would the car still be able to run normally once it had warmed up?
not unless they somehow find their way to the correct plug or position on the cap when warmed up.. did you check for codes yet? you only need like 2 minutes of free time, the ability to count blinks, and a paperclip. Have at it, let us know what you find out.
i may be an idiot and somehow did it wrong, but no codes came up
im pretty sure i did it right though because i put a paper clip in the top two righthand corner slots and when i did that, my second fan came on. when i took the paper clip out, the second one shut off and only the first one remained on.
i tried many times turning the key on and off, repositioning the paper clip, but no codes came up.
anyone know what to do now?
You don't have to tear out the cluster.... just pop the bezel off. What is it, about 12 Torx screws; takes around 90 seconds to pull the bezel, change a bulb, and put the bezel back on, if you stop for a cold one halfway through.
But, excellent idea, verify that in fact the light doesn't light with the key on and engine off. Somehow I doubt you'll see it come on though, since the ECM seems to be doing everything else right.
__________________ "So many Mustangs, so little time..."
the light does not come on when i start the car or just put the key in the on position
im a little confused about how to change the bulb though...its recessed in this white thing and seems a little difficult to get it out and get a new one on. how would i go about doing this?
It's a good thing you removed the I/P bezel and replaced the lamp. That will have been good practice. The VSS on an '87 IROC is on the rear of the I/P, attached to the speedometer. Make sure the speedometer works, and the VSS electrical connector is plugged in.
That shouldn't cause any smoke, however, and should really not affect how the engine idles when cold. Still, it needs to be repaired.
Originally posted by rsn932 so the VSS has nothign to do with the cold idling problems i have?
nope.
was 24 the only code you got?? if you wait long enough, it will flash more codes if they are there. Each code will repeat 3 times, then it goes to the next code. when it gets back to code 12, you have gone through the whole list.
I would say it's a fair guess you have more than one code set. An MAF code or TPS code would not surprise me.
If you have an MAF code (33,34,or 36), try unplugging the MAF altogether. When my MAF went bad, my car ran like you're describing. When I unplugged the MAF, it ran fine, but the SES light came on. I drove it for a week or two with the MAF unplugged, with no problems, until I got the $$$ for a new MAF.
If you do have an MAF code, and unplug it, keep in mind that's only a band-aid fix, but it will get you running until you can troubleshoot/repair the MAF system.
As for the smoke, I would say before you make too much fuss of it until youget it running good enough to change the oil, and take it out on the highway a while to clean that motor out.
yes code 24 was the only one i got, it flashed 3 times and then went back to code 12 again
as for unplugging the maf, i have already done this and it starts up and idles fine, but someone told me that doing that just puts the engine into a default mode of some sort that changes things like air/fuel ratio, so unplugging the maf doesnt really tell you if the maf itself is the problem. i am not sure about this though, anyone agree or disagree?
Originally posted by rsn932 yes code 24 was the only one i got, it flashed 3 times and then went back to code 12 again
as for unplugging the maf, i have already done this and it starts up and idles fine, but someone told me that doing that just puts the engine into a default mode of some sort that changes things like air/fuel ratio, so unplugging the maf doesnt really tell you if the maf itself is the problem. i am not sure about this though, anyone agree or disagree?
I don't think running without the maf puts the ecm in limphome mode, if that's what you mean. I ran without mine for a couple of weeks once, and the car ran like normal. Didn't show any signs of being rich or lean, never pinged, got the same gas mileage as before, etc. I was so happy with how it drove without it, I wouldn't have bought a new one, except I wanted the SES light to go out. When you run the engine with the maf unplugged, the ecm has to calculate air flow based on other sensor data, such as throttle position, rpm, etc. The computer's calculated "guess" is less accurate than a functional MAF, but it is more accurate than a malfunctioning MAF. If unplugging the MAF makes it run better, I think that pretty much isolates your problem to something in the MAF system. I would clean the electrical connections at the MAF, and at the MAF power and burnoff relays. Also test the relays, to be sure that they are working well.
BTW, unplugging it will set codes 33 34 and 36, you will want to clear codes before plugging it back in.
ok thanks guys i will check/clean the maf connections...hopefully it will fix the problem
any other ideas before i spend a couple hundred $$ on a new maf?
Originally posted by rsn932 ok thanks guys i will check/clean the maf connections...hopefully it will fix the problem
any other ideas before i spend a couple hundred $$ on a new maf?
How does it run with the maf unplugged? Better, worse, or same?
$60.99 for a new wells SU-145. If you do a search for su145, you'll find a few pictures of this unit. Supposedly it flows much better than the stock maf unit.
One other thing to check is the throttle position sensor. Have you checked it's resistance, and idle setting?
car runs much better with maf unplugged
i have not checked the tps resistance or setting, how would i do that?
thanks for the link to the wells maf, at newgmparts.com a new stock maf is like 400 and something dollars
I just verified this with my supervisor. Your problem came back as cylinder wall scoring, possibly caused by the previous owner running the car hard while it was cold or low on oil. You want to perform a compression test, if it comes out bad, then you will need to have the block machined and then buy oversized pistons.
At this point, why stick with the wussy 305? I mean, a supped up Honda civic will take you. And the 350 is such an easy conversion, really you are just throwing money away. I think everyone will agree with me here...
Bob from CA Performance
ps go with ry 121, thats the best one for your car
why do you list your thermostat modification? lol its hardly worth mentioning
Last edited by camarogodo; 05-25-2004 at 05:03 PM.
camarogodo,
with cylinder wall scoring, would the engine appear to be running fine after it has warmed up? because it really seems like it is perfect after warming up for 5 minutes or so.
and it runs great when the maf is unplugged so im a little confused?
just my opinion it doesnt seem to be that serious, unless unplugging the maf makes it run rich enough to offset the scoring.
i still dont understand how it can run fine when it is warm if that is the problem.
One of my fellow employees had this problem, I cant believe the symptoms are so similar! Yes when the engine warms up the rings expand a little more to compensate, but the more you drive this car the worse the problem will get. Unplugging the maf should also do exactly what you said. The car will sense this and run rich to be safe, and you wont notice the roughness as much.
We had the exact same problem!! I hope your compression test comes back ok, be sure to use the special camaro sized compression end available only from a dealer.
1) Set 3 codes (33, 34, and 36)
2) Illuminate the SES light
3) Put the ecm into Alpha-N mode
When the ecm is in Alpha-N mode (which, by the way, is NOT limp home mode), it bases it's fuel/spark calculations on TPS/RPM data (i.e. at a given engine rpm with a given throttle opening, the ecm knows how much air the engine *SHOULD* be drawing.
Unplugging your MAF will NOT:
1) Make your engine run rich
2) Cover up for any major mechanical defect of the engine
Cylinder wall scoring will:
1) Cause low compression
2) Cause excessive oil consumption
3) Cause excessive cylinder blowby
4) Be bad news
5) Often times cause audible engine knocking sounds when the motor is cold, as the pistons (cold, so not expanded to operating size) cock in the cylinder bores at top and bottom dead center
Cylinder wall scoring will NOT:
1) Be the first conclusion you should jump to when troubleshooting a minor driveablity issue.
2) Cause the driveability issues you are currently troubleshooting.
You have some sort of fuel/spark problem, caused by an as yet unidentified sensor sending useless data to the ecm. My money is on the MAF.
What did your spark plugs look like? If they were relatively clean (of oil, at least), you can rule out cylinder scoring. Cylinder scoring will cause high enough oil consumption to make spark plugs look nasty pretty quick.
You could rebuild your engine, like camarogodo suggests, but if you don't find and fix the cause of this problem, your newly built engine will have the same problems.
guys i just figured out my brother was playing a joke on me, he just created the name "camarogodo" to scare me into thinking i needed a new engine....
that aside, does anyone know which of the relays i need for the maf listed a few posts ago, since my brother just randomly picked one?
thanks and sorry for the confusion
