Hey everybody, just got ahold of an 87 GTA from a friend of mine. He put about 5K into the motor. Complete rebuild with lots of modification. New motor has 150 miles on it. It was running rough when I bought it, we knew some plugs were bad. A week after I got it, it wouldn't start. Things I did:
1. fuel pump...ok
2. fuel filter...clogged/replaced
3. plug wires...fried and replaced
4. distributor...firing order is ok/spark to all 8 cylinders
5. fuel injectors...~17ohms
6. plugs...old ones were covered in black/replaced with new AC Delcos
STARTED
The car had been sitting for about 2 years, so I drained the tank, put new premium in it with some SeaFoam, and it ran fine once it worked out the old gas. Then, after running for about 10 min, it began idling rough and backfiring. It would then backfire only when opening the throttle. Then it would die when put in gear. Trans leaks, so I filled up the trans level and it would idle fine but still die under throttle. All of this happens in my garage, not on the street. Now, it will not start period. I pulled one of the new plugs out and it looks just as bad as the ones that came out. I can't tell if it's oil build up or fuel. I know the car has to be running rich, I can smell it, but the plugs look like the typical oil fouling, not fuel fouling. They look too dark to be fuel, to me. But I don't have too much experience with fouled plugs. After reading the threads, I think I'll check out the t-stat and O2, in case one or the other (or both) are failing, but I was wondering if anyone has had this happen? Am I simply running too rich and need to lean out, is it possible my injectors need to be cleaned, is it an oil/fuel problem? Any help would be greatly appreciated. I'm checking this thread in between classes. Thanks guys.

 

Welcome to TGO

1) Do you know a list of modifications? How big is the cam?
2) Check fuel pressure (Stock tpi should be between 39 to 47 psi)
3) Do you have spark to all cylinders now?? (you had it before)
4) Connect a test light to Fuel injectors during cranking - do you get a blink?
5) Do you have ALDL cable and laptop? Ideally a data log secession would reveal a lot about your engine.

//RF

 

Here's a general list of mods:
"High volume and pressure oil pump(standard. pressure spring avalible.)
Polished and chanfered crank shaft
230,000 psi rod end cap bolts
re-mechined rods
Flat top pistions .030 over and rings
high speed harmonic ballencer, and racing flexplate
Completely internally ballenced.
Peterson Dual-idler gear driven cam gears(and aluminum timing cover)
Comp-Cams camshaft, (I have the spec. sheet somewhere, but its the largest that would work with the computer) lift is about .480
New hydrolic roller lifters
New push rods
1.6:1 roller tip rocker arms (making the overall lift over .500) springs to match lift
Heads milled 0.010 for compression around 10:1
1.94 intake values
1.50 Manely exhaust values
Ported and pollished heads
Edelbrock Headers"
^ his grammar, not mine, lol. I do still have spark @ all 8 cylinders, I have an ALDL cable on its way that should get here any day and I have a slew of programs on my laptop.

 

87GTAj

Since you have spark to all 8 cylinders we'll assume that ignition system is OK (for now). On the other hand high pressure oil pumps are known to put additional load on the dizzy gear. It is not uncommon for dizzy gear being 'eaten' up by the cam due to additional load presented by high volume oil pump. In no start cases I would also - recheck basic timing, just to make sure that 0 TDC corresponds to dizzy pointing to #1 Cylinder. When dealing with aftermarket combinations I always check basics - which may prove to be redundant, but stranger things happened in the past.

For engine to start it must have:
1) Static compression in all cylinders - simple static compression check.
2) Proper ignition timing - verify TDC vs. dizzy vs. #1 Cyl position.
3) Good, adequate fuel atomization - injectors firing? - fuel pressure?
4) Starter speed - adequate???

//RF

 

Alright, I was looking at it some more tonight, and haven't found anything new. I got a timing light from my friend, and he said the timing was at 4* when he set it up...not sure why exactly. I haven't moved the distributor since I've had it, only changed the spark plug wires. I plan to adjust the timing once I get it running, to 6*. I don't have any time to work on it until Thursday really, so I'll check some of those things then. How would I check the starter speed? Nothing sounds abnormal with the starter. What is odd to me is the fact that I've been looking at the car on and off for about two years, and it only failed to start when the battery needed to be charged, and it ran fine for a week once I bought it. (I know sh*t can just happen, but still) New spark plugs got it working, then dead. Does it look like a fuel issue, fouling the plugs? I'm debating trying a new set of plugs just to see if that gets it started. Thanks for the help

 

Running really really rich from the get go huh? How about that world famous CTS. Stalling before gear, in park and just whenever? How about those great MAF relays. Honestly, you need to do a good amount of diagnosis before anyone can try and pinpoint anything, right now there is WAY to much to point to without even getting into any of the build.
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Wow, that pic just loaded for me. If it's as bad as I think it looks, I'd start with a comp test and leakdown first, that is a whole lot of crappy looking... then again the pic ain't so hot neither.

 

'87GTA
Turn engine until you set 0TDC on balancer - Use breaker bar to turn engine by hand. Pull #1 cyl plug verify that piston is at a TDC. I know - it is PITA, but it is the only way to make sure. Take dizzy hat off - mark rotor position on the body of the distributor - that's your #1 reference. Now, see if your spark plug wires are routed to corresponding cylinders. I have messed up wire routing before on a few occasions. Check and verify. and do not give up!

//RF

 

Mine did this after my mods. Fouled and died. Same looking plugs and all. My O2 got damp during my re build. Replaced it runs great `!

 

I guess there's two O2 sensors on these cars, which one (or both) did you replace, BA?

 

Only one on passenger side

 

Alright, I'll give that a shot and see if that does it. Given that everything has remained unchanged, it just fouled up and died, I would like to think that a sensor went. I'll let you know. Thanks again for the help

 

GTA - hold off on replacing a O2 sensor for now. When engine is cold ECM will run in open loop based on stored fueling values until CTS reaches about (depending on calibration) 60C and within 2 minutes from engine start. While it is cold it will run rich. After that ECM will attempt to enter close loop. If NBO is truly fouled and does not provide cross counts or remains in tight window around 450 mV you'll get SES light.
For now just get her started is the key. You can see what ECM is doing with ALDL and appropriate software.

//RF

 

Alright, I got the cable today, and I hooked it up...got 122 across CT (which I assume is coolant temp) and a blinking 5. I believe I need to use the 10K as well. Will the software give me enough info (possibly tripped codes) if it is only in "on" mode, or does the car need to be running to get full info?

 

What did you do besides change the O2 sensor to actually get it started when that happened?

 

87GTAj

Aghh - Ok, Can you post which ECM and broadcast code you have?? Also, which software are you using??? Take screenshot and post it so at least we can have an idea. With WinALDL you should be able to see several parameters with engine not running, but that is 160 baud ECM only pgm....

//RF

 

I would assume ECM is 1227747 or 1228062, that seems to be what WinALDL is telling me ( I haven't looked at it yet). Brodacast code, I'm not sure. I have only used WinALDL so far, although I have datamaster, freescan, tunercat, aldl-165 and a bunch of other choices. Which one would you recommend using for diagnosis and which one for datalogging? This is the first time I've tried the OBD1 cable...would you happen to know which configuration of pins I need? I followed the instructions and have pins on A, B, and M if I remember correctly. Do these cars need the fourth pin connected as well? (I have pins since I bought the cable from MASTACH). Here's a screenshot of what I got; the five was flashing red and everything else was 0, EVERYTHING. One time I tried cranking it, the PROMIDB had 17's across it.
Thanks again

 

I bought my Camaro from a guy that had just dropped in the motor, it ran at first and then ran like crap, then quit alltogether. He took it to a shop and they told him he had bad wiring bad sensors, bad ecm ect....

I bought it, unplugged the mass air sensor and it fired right up, drove it up on the trailor, replaced the sensor when I got home and it ran perfect.

This may not be your problem, but it takes about 10 seconds to try.
(it probably won't idle very well if at all with it unhooked) hold the throttle.

 

GTAjr

WinALDL does not auto detect ECM type!

Well - you really need to take a look at your ECM. 1227747 ECM is used in TBI Trucks. Your GTA is a TPI equipped car. Based on several sources, if your GTA still has its factory ECM, it is probably 1227165. 5.7 L engine may have a number of different Broadcast codes (BUA, AANK, AANL, APYP, APYU, AUJM).

So in WinALDL you'll have to select proper ECM. Also make sure that Com port is set for 4800 bps - default is 2400 for some reason.

Under Sensor data you should see current data even with engine off, ign on.

Going through a learning curve now.
//RF

 

I don't know if that GTA'jr' was a typo or a shot, but whatever. It's not that I don't care about looking at the ECM, or that I think it doesn't matter; like I said, I just got the cable, I tried it out, it wasn't working, and that's all the time I had at the moment to troubleshoot. I was reading different FAQs and found I need to specify alot of info with WinALDL. I am aware that I have a TPI motor, I'm not completely retarded, and I beleive you are right about the ECM number, that's what I keep coming across as well. However, how would I determine which broadcast code I am working with? Trial and error or would it be specific to something? I am going to have some time tonight to hopefully get the ALDL cable working and pull some info. When I do, I'll post some screenshots or the info itself.
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I'm going to see if I can get my hands on a manual to check over the relays and things for the MAF. I'll see if the MAF being disconnected does anything, maybe give it a good cleaning and see where that gets me. Thanks for all the help guys.

 

is it running like this by any chance?
http://s54.photobucket.com/albums/g8...t=bc9c202e.flv


i replace every sensor u could think off came to found out it was the ECM...

 

Currently, it isnt running, but before it died, I would say it did sound very close to that. Exhaust definitely sounded the same.

 

1) It was a typo and I only shoot at my local range.
2) Since you are new to these ECM equipped cars you have a lot to learn. It is very important to have patience and discipline when working on these cars. Many people fail to resolve simple problems by not following through a factory test configuration setup, making false assumptions, or worst yet by blindly replacing parts. Frustration levels rise, wallets get thin - you get a picture. We try to avoid going that route by helping each on this board. We try to keep these cars running smooth and proud - these were dream cars of my younger days.
3) ECM in your car is the key - it control all aspects of engine operation. Depending on the vehicle type and EFI different ECM maybe used. In your case determining ECM is very easy. There is a label on ECM cover that specifies ECM service number - 1227165 and Broadcast code which specifies calibration data for your vehicle. For parts commonality GM used same service type on number different engines and vehicles by simply changing broadcast code - calibration. ECM is placed inside passenger side foot well behind plastic cover. If you do not want look at it - you can change ECM type in WinALDL to 1227165 (you may have to play with a baud rate) and see if you are getting valid data.
4) Since you have highly modified engine it is most likely that in the future you'll have to look at ECM and learn how burn your own EPROM's. For now just starting and getting it to idle should be your immediate goals.

//RF

 

Yeah, my main concern right now is getting it to start and consistently run. I really want to take the car out and enjoy it before we get snow.

Ok, so I can't seem to get WinALDL to work. I tried changing the ECM to the appropriate setting, and the baud rate, but it won't read anything but CT 122, and a flashing red 5. I tried messing around with my comiputer's COM settings, but no luck. Does anyone know exactly how the pins should be hooked up (black, red, white, blue)? I think blue is not used. I want to make sure I have that connection correct first. Also, does anyone have tips on troubleshooting the computer - COM - cable connection. Mine seems to work only on COM 1, which is my only labeled COM port not occupied by a printer or bluetooth. I tried disabling both other COM ports (printer and bluetooth) because I heard they can interfere, but nothing. Thanks.

 

I'm trying to locate the ECM, just to make sure I have the correct one selected in WinALDL, and I am not entirely sure what I am looking for. I have the passenger side dash apart below the "glove box" and I am confused about where I'm supposed to look. The first picture has a black box that looks like it could be an ECM, but the only number on it doesn't match anything else. There is also a large plastic cover I could not completely remove underneath that, as seen in the second picture. Help would be appreciated.

 

All thirdgens came from the factory with the ECM mounted vertically behind the passenger side dash.

It's basically right behind where the map pocket is, if your car happens to have one. Once you remove the lower plastic trim piece (can't recall GM's name for it), you should be able to look up and see a plastic or metal bracket about 6" wide that is held in place by two 7mm hex head screws. Remove those, and the ECM and bracket will drop down together.

 

I'll check it out, I was looking at it today and yesterday, and the only things I can see inside are what I believe is the antenna and that large black plastic covering in picture 2. I pulled out 3 screws from it and it moves, but I can't get it off. Do you know if the ECM is hiding behind that?

 

You are looking for aluminium looking box. Here is a link to typical C3 ECM
http://www.dynamicefi.com/img_0388_a.jpg

Depending on installation ECM may be enclosed in a plastic housing which is used for mounting and protection. Gen3 have ECM mounted against passenger right foot well, just past door jam - covered by interior plastic cover. It is not mounted inside dash.

//RF

 

Ok, so I have been talking to some people, and they have been suggesting that maybe I have a vacuum leak. I wanted to check out all of my vacuum lines, but I'm not sure where all of them are. Would the Haynes manual have hose diagrams in it? I was told by my friend that he had the manual for the firebirds 82-92 and it had info on all of the motors except the 350...most of the info is on the 305. Can anyone verify this, and are the vacuum lines shared between the two motors? Is there a better repair manual for the car AND the 350? Thanks

 

305 and 350 are the same. I doubt a vaccum leak is going to make it not start, unless it's a really bad leak. It sounds like a timing problem, are you absolutely sure you have set your base timing, and then set it to the right degree?

 

Well, I haven't set it myself, but it was set up correctly when the rebuilt motor was installed. Timing is supposed to be at 4* right now. I'm not sure why he set it there and not 6*, but that's what he set it to. The timing can't get messed up on it's own can it? I believe he put a new timing chain and cover on when he rebuilt it. I would figure that would still be fine, not worn too much. Right now, the motor has 154 miles on it. Any reason why it would run fine for so long and then die now? Why the new plugs worked the first time to get it going, but not this time?

 

I think you need to start with the basics:

Get the motor at TDC (top dead center), make sure the rotor is pointing to the #1 wire, chech to make shure the firing order is correct, 1-8-4-3-6-5-7-2 (I think that's what it is)

Don't worry about degrees right now it doesn't matter, just get your base timing set.

 

I know the firing order is correct, I've checked it twice. But can the timing be off on it's own? I'm almost positive he put a new chain on it and it was running before.

 

Just to be shure that's not the problem, I'd check it. Make shure all the basics are in place:

1:Fuel
2:Air
3:Spark
4:Timing

And go from there, I've seen it happen so many times, people try to overcomplicate things (if that's even a word), and it turns out to be something simple.

 

I checked the fuel injectors again, and this time, instead of all being ~17 ohms, I got the following:
17.1 16.1
17.2 16.0
17.1 16.1
17.2 16.0
Is it odd that just the driver's bank is lower than the last time I checked them?

 

Hey guys, sorry, it's been pretty hectic with school lately. I finally got a chance to work on the T/A again. So here's what I have:
Compression - OK
Timing - OK
Starter Fluid in the intake - wouldn't start
Changed ECM's to a remanufactured one pulled from the junk yard - wouldn't start
However, I was able to get WinALDL to work, and below are some screenshots of the results. The only thing that looks odd is the MAF reading...it looks to me like it's reading 15g/s when the car is not running, which I would think would be zero. IDK. WinALDL will only work with the "new" ECM, not the old one. The first two screenshots are from the new ECM, and the last one is from the old one. Also, the ECM I pulled did not have the yellow chip attached to it, as seen in the last photo. Any help on decoding them or more troubleshooting tips would be appreciated. Thanks

 

Last Photo

 

The MAf is reading is not zero because the throttle isn't completely closed.

 

Do you have spark to the plugs? If you have fuel, compression and the timing is correct all you are missing is spark.

I had a problem with mine last week, it started running like crap, then died. All it turned out to be was that the ignition rotor came loose.

 

I do still have spark, but is it possible that the spark is too weak? I was also told to try running a fuel line directly from the tank/filter to the fuel rail to bypass the rest of the system in case there is a problem in it. I thought the starter fluid would put that to rest, but is it still something to try?

 

Shouldn't the throttle be closed if the car is just in accessory mode?

 

So I decided to check and replace the fuel pressure regulator diaphragm after talking to some people and reviewing some threads; the old regulator felt worn, but it did not fix the no start issue. I let the fuel pump prime before I tried starting the car, but is there a specified time you're supposed to let the pump prime after installing a new fuel delivery component? I didn't think so. Also, I noticed that when I was trying to get it started, the fans would not come on, period. This is odd because they are set to come on regardless of temp as long as the ignition is in the "acc" or "on" position (don't ask why). Does this mean there may be an electrical issue as well? I got a set of injectors that are known to be working from my cousin's '88 GTA, and my next step is to swap them out and see if I get any results. Help is still appreciated. Thanks

 

You gotta stop throwing parts at it. You may be introducing new problems. If it won't run on starting fluid it's probably not the regulator, injectors, or anything fuel related (unless it's flooded). If you have spark, it is most likely timing. You may have the distributor 180 degrees off. If you don't know how to find TDC, just try moving all the wires on the cap to the one opposite where they are now. It will only take a couple minutes.

If that doesn't work. You might have a leaking injector and the engine is constantly flooded. So pull the fuel pump fuse, try to start it, let it sit for an hour or so, then try with starting fluid again.

 

I already verified TDC vs. dizzy, so I am pretty sure that isn't it. I am trying to avoid just throwing parts at the car because I've seen that go sour before. I only tried replacing the regulator because I was told that it could very well be the problem based on the symptoms I was seeing, by several people who know what they're doing. I'm in the middle of swapping the injectors right now, and this is what I found so far: there was no pressure in the rails as the Schrader valve released no gas. (normal since the car has not been run in awhile) When I got a couple of injectors out, however, fuel was just pouring out of the rails. Could this be pointing to clogged injectors? I'll let you know how the swap goes.

 

Can you tell us how you verified that the engine was at TDC when the rotor was pointed to #1?

 

I pulled all the plugs out, rotated the motor using the nut on the alternator until I hit TDC compression stroke of the #1 cylinder. I knew it was on the compression stroke because my assistant was waiting for pressure on his finger in the plug hole during piston travel. Once he felt air pressure, and then the pressure was relieved, the piston had just passed TDC compression stroke. Do you have an easier/better way?

 

That should work as long as you lined up the timing marks. What you're saying just doesn't make sense. If you have spark, fuel (even starting fluid), compression, and the timing is right it *will* run. Even for just a few seconds.

 

The fact that it won't start says that one of the requirements is missing, ( like compression could be less than the minimum 80psi,) if all are present then timing is off.
If you're turning it manually then you should feel compression before it reaches TDC.
Even if you've past the TDC just continue turning, the next TDC will be #6 compression stroke, now stop at the next TDC, and check to see if the rotor is pointing at the distributor #1 spark plug wire terminal. If it isn't, but is point directly at a terminal then reorder the wires so that terminal becomes the #1, else pull the distributor and realign.

If you decide to realign, keeping the oil pump rod align is a must.
Do the following while keeping track of the #1 TDC strokes.
1.) continue turning the crank until the rotor is pointing where you want the #1 to be, or at the stock location.
2.) Pull the distributor
3.) rotate crank to the next #1 TDC compression stroke.
4.) reinstall the distributor with the rotor pointed at the #1.
FYI:
Because the oil pump shaft coupling uses a slot there's only two positions where it will engage completely #1, and #6.

If everything else is good then there's absolutely no reason why it shouldn't start up on the first few cranks.

Good luck and keep posting till u get r dun!!!

 

They said exactly what I was going to say, If you have all the elements in place it will run. Have you checked compression? I would still say to double check the base timing though, if you're off 180deg or even turned a little too much one way it won't run.

 

So I was in the process of changing the fuel injectors, when I found a couple of things that didn't look right to me. In the photo, there is a wire supposed to be attached to the circled part (pardon my ignorance here), but the wire was pulled out of its connector. What am I looking at and will it not being connected affect anything during ignition? Also, there are two vacuum lines coming out of the rear passenger side of the plenum...the line closest to the distributor (I believe it's the HVAC line) was rotted completely through where it meets the plenum. I hope this would not affect anything during ignition, but am I wrong in thinking it's the HVAC line? Swapping to working fuel injectors didn't get the car started, but I thought I heard a backfire on one of the tries. I guess I'm gonna check the timing AGAIN. I was positive the timing was correct, and I read on another forum that the base timing is usually set where #1 is at roughly 5 o clock; it did end up that way on my dizzy.

 

87GTAj

That's your EGR valve. Just plug plenum taps for now. Deal with HVAC controls later.

Regarding base timing. Do you have stock balancer or after market? Also, I have heard about outer ring slipping on very old balancers...
//RF