mrrman

Ive parked my car for winter and occasionally started it and it turned over fine. I decided to replace the battery with a higher CA capacity. The car turns over but doesnt fire. What should I be looking for? There is gas in the car and I drove the car throughout the summer.

robvano

iTrader: (3)

I'd start with checking fuel pressure and ignition. Spray a little Engine starter fluid into the intake thru the Pcv hose. If its got ignition it will try to start and possibly run for a couple of seconds.
Did the problem start just after replacing the battery? Post what set up you have, so others may help. Is it stock TPI?

Check to see if you have power going to the Dist.

mrrman

No, it was happening with the old battery installed to, but started to happen after 2 months of bring parked. When I try to turn the car over I can smell gas once the pedal is depressed. The fuel pump and sending unit were also replaced during the summer. This is a stk 350 5.7 engine.

mrrman

http://www.ebay.com/itm/Ignition-Coi...item2318cacc48


I was told that it may be the coil. How do i test to see if thats defective? Would any coil replacement for the 87 TA 350 5.7 be okay?

cal30_sniper

iTrader: (16)

Sounds like VATS to me. There are two circuits in the VATS system. One tells the computer not to fire the injectors, the other doesn't allow the starter to turn over. Sounds like your VATS has triggered and the injectors aren't firing. Better check the VATS delete section and either wire in a resistor or remove it from the ECM altogether.

-cal30sniper

mrrman

Is there a VATS in an 87 TA GTA? My key has no chip in it...I was told to check the coil out...

mrrman

A new coil was installed, same issue. Any ideas anyone?

Thanks

BrownBullet83Z

I think we all need a little more info. First off, why did you replace the coil? Did it have no spark or were you just going off someones recomidation? robvano had a great quick and easy troubleshooting technique. Make sure the battery is charged and give it a blast or 2 of ether. If it fires briefly, you know you have ignition and fuel is your problem. If it doesnt, chances are you have no ignition (spark). If thats the case, check to make sure the cap didnt get wet and/or freeze or module didnt go south. Also, did you try to jump before you replaced battery? Could you have crossed the cables? If so there could a blown fuseible link or shorted PCM (I hope not but have seen SEVERAL times). Look into this stuff or fill us in if you already have and I'll shoot some more ideas at ya. Good luck!

hwy101

COULD BE A FUEL PUMP OR THE FUSE

mrrman

Fuel pump and sending unit were changed out in the summer

mrrman

The coil was replaced on a recommendation through a friend as we talked over the phone, it was a simple cheap process so didnt lose much. It had a brand new 650CA battery installed. The car was never jumped. The gas is good since i filled it up and ran 1/2 a tank through the summer months ( late Sept)

BlackenedBird

iTrader: (5)

No VATS in 87 for 3rd gens. It started in 89.

Conradzz

I recently had a problem where my car would start intermittently. If your getting no spark, the ignition system is pretty simple. There's a few things that would stop the car from firing. Pickup Coil being bad, Ignition Control Module being bad or dying, Ignition Coil is bad. On a rare occasion it could be your ECU, not sending a signal to the ignition control module. One simple way to diagnose if its your ECU, is backprobe the wires going into the Ignition Control Module, with the key on. You should get a 5v signal. If so, you can eliminate the ECU being bad. Another thing that is simple to diagnose is a bad pickup coil, probe the 2 wires coming from the coil, and turn your meter on ohms. For my 92 firebird, anything between 500-1500, was considered good. Now that just leaves you with the Ignition Coil, and the Ignition Control Module. You said you already replaced the Ignition Coil, so I'd say your problem is the ICM. They tend to get really hot when in use, and aren't too far off from common in dying.

You can take it off, and have it checked, but it won't really tell you if its good or bad. I had mine tested, and they said it was good, so I went ahead and replaced it. Car has been running fine now, for almost a week. Whereas before I couldn't get it to stay running for more than a couple seconds.

Anyways, hope this helps, if you need anymore info or help, just let me know.

mrrman

the ICM is located in the distributor cap...is that correct?

Conradzz

You have to pull the distributor cap, and its bolted down to the metal base of the distributor. You unbolt it, undo the connector for the pickup coil, and it pulls right out. Watch out though, it has some dielectric grease on the bottom of it, to help with heat dissipation. Like I said, there's not much point having it tested, as it doesn't really tell you much. The most it could tell you is if the test comes back bad, that its for sure bad, but if it comes back good, then it can still be bad.

Make sure if you replace it to buy some dielectric grease, and apply an even coating on the bottom of the metal plate. Another issue you could have with your ICM, is if the screw holes are badly rusted. It gets its ground from those bolt holes, so before replacing the ICM, you could try cleaning up those bolt holes, and seeing if that works. Also be careful with the pickup coil clip, my broke off pretty easy.

mrrman

Okay...thanks for the info...I will try this next

mrrman

I just installed a new ICM...same issue. Can anyone shed some light on this. What should I look for next? Thanks

mrrman

If all the wires are good, which i bet they are and the battery is good ( 100% +ve on this) , then what? If I find that there is no spark, what should I look for given I have replaced almost everything that has to do with a spark. Are there any relays involved anywhere?

mrrman

Could it be a faulty PCM or MAP sensor causing this? I am kinda shooting in the dark here. I dont want to spend $$$ on parts if I dont have to. How do you know if a PCM fails? Its just a computer box under the dash??

Conradzz

Ok, how do you know your not getting any spark? Have you tested it at all, the map sensor should not restrict spark. I'm assuming PCM and ECM are interchangeable. You've still got 2 major things that play into spark, your ECM, and the Pickup Coil(don't get this confused with ignition coil). To eliminate the ECM being bad, test for 12v on the pink wire going into the ICM while the ignition is on(not the one coming from the ignition coil). If that's good, I say the last thing you can try is replace the pickup coil, which past that point, its quite hard to do. You have to remove the distributor, pull it all apart, then replace the coil, and put the distrib back in and re-time the engine.

mrrman

The ECM/PCM are the same thing, is that correct? Its the computer module box under the passenger side dash. I hope thats its not the pickup coil, that would be a pain to work on.

mrrman

Okay...I pulled one of the spark plugs out, touched it to the chassis and turned the car over. There was spark. Now what do I do? Any help appreciated. Thanks

BlackenedBird

iTrader: (5)

That should narrow it down to fuel or bad timing. If the spark doesn't fire at the right time, it ain't gonna start.

mrrman

As in bad fuel? Cn you please explain. The car was filled up in the fall and sat throughout the winter. Occasionally I started it up and it fired all of a sudden it stopped firing. The fuel guage is reading 1/2 full.

mrrman

Could this problem be as simple as a fuse blowing somewhere? If so, how many fuses and locations are there in the engine bay area?

mrrman

Okay...I tried a few more suggestions, jumped the pins on the diagnostic connector, no codes were displayed so that could not be verified. I tried starting the car by primimg it as suggested by another member, no luck. One thing I noticed is that my oil presuure was at 0 all the time when doing this. I suspect that this is the problem. Where do I look next to correct this? Thanks

hwy101

change the oil pressure sensor it should be right by the oil filter its 15.00

mrrman

That was my next guess...thanks

mrrman

The oil pressue sensor was replaced and there has been no changes....I am at a loss now...any other ideas before I get this car towed to a shop Thanks

mrrman

I have an Actron CP9145 scanner now which I just hooked up to the car. It says that a connection is required but it is hooked up. Does this connector under the dash run to the computer? If so, would one assume that the computer is shot and that is why I am not getting any readings? Would the computer be the culprit for all my problems that i am having? Thanks

91 zeee

I dont think this was asked above, but... when you turn the key (before you crank it) do you hear the fuel pump for a few seconds? (if so, have you checked fuel pressure?)

z28m8

hey guys, i have a prob thats driving me absolutely effing crazy
just built a 383 for my 3rd gen, now its in the car i can turn it over but wont start, checking it out ive found i have a medium/low spark at the coil BUT no spark at the plugs???? ive got a new dizzy/coil/leads and ive also swopped the dizzy and coil with a friends that i know works as i drove the car in my garage.... the ignition coil feed voltage drops to about 8v when cranking,ive also hard wired the coil with a separate charged battery but still no spark!! before the dizzy spark disapeared all together it tried to fire but allways seemed to be well out of ign timing,every time i adjusted it we lost the spark.... all earth continuity checks out,(battery,body,engine)
please give me an idea as this has me and a few other car friends really baffled, and is pissing me off!!!!!!!!
thanks,shaun, england

mrrman

I have exhausted all options and I am ready to have this car towed to a shop. As one last ditch effort, should I buy a computer from Ebay and give that a try? Its about $150. I have run out of ideas and have tried all of your suggestions.

mrrman

I shot some quick start into the intake and it tried to run. I am going to put in a new knock sensor and see if that solves my problem.

Patrick Day

I would look at the fuel pump or the fuel pump relay

BrennenK014

Wow weird timing that I had came across this post, I JUST tryed starting my trans am, same year even. Same issue asyou. I was reading all of your posts, and check the rack, see if you have fuel coming up, if so let it shoot up a bit, hold it open using a key or screwdriver or something small, not only will you know your fuel filter aswell as your pump are in tact and working but you can also see how much pressure there is. That was my first step so now, I know my pumps working and I have great pressure. Next led to mhm, what turns it over but wont fire? You need spark, next thing I did check my wiring for spark, turns out I have no spark. So now I need to figure out exactly where my issue is, anyone have an idea of where to start? I was thinking the distributor or something

mrrman

they have been replaced a few months ago

mrrman

I am sure learning alot about this car. Another suggestion that I had was to take a look at the main computer to see if it was fried or had any visible symtoms of being bad. Removed the computer and it looked fine. The next suggeston I will try will be the relays for the MAF, fuel pump etc.

BrennenK014

Mrrman, this might sound ironic but check your immobilizer. The older ones tend to mess up quite frequently and honestly. I just got my car running today because I realized it was my immobilizer the whole time, after changed my fuel filter, ignition coil, distributor rotor etc. I would turn over no fire, at first I thought my pump was gone, checked the fuel rail, had gas coming up and pressure. So i figured no spark, so thus changed my coil and rotor and still nothing. Then for some reason turns out it was my immobilizer, I fiddled with it a bit and started first turn over. May sound stupid, but have it looked at. Trust me

rick90gta

iTrader: (3)

getting spark by touching a plug to the manifold doesnt necessarily mean its going to start. you can get moisture in your distributor cap and it will cause spark scatter in the cap, not letting enough juice get to the plug when its trying to fire under compression in the engine. you can usually take the cap off and see little beads of water in it when this happens. sometimes it will look like a yellowish or white haze inside the cap. if the fuel pump runs and you have adequate pressure i would look at fuel injectors. ive had the same problem with my GTA after it sat for a while. i think the gas sitting in them gets to the wrapping on the coils. if thats the case good luck fuel injectors on a tpi really suck to change... pcm would be a last ditch effort in my book if you have spark. if you can get at a connector and have a test light check that you have pulse at the fuel injector. if you do its not likely to be the ECM

rick90gta

iTrader: (3)

you can unplug the MAF and see if it runs it might not run well but if thats the problem it will force the ecm to ignore the maf input and use the other sensors for its calculations

mrrman

Ive tried this to without any sucess

mrrman

I dont think I have an immobilizer on this car...no alarm system etc

BrennenK014

I didnt think I did either, but then I had found a hidden blinking red light. Keep checking.

ploegi

are you getting injector pulse? (you can get a noid light at the parts store pretty cheap to check it.)

mrrman

On the off chance that they arent pulsing...what would cause that? I am currently away from home.

ploegi

Batch fire system, ECM fires one bank at a time. If you aren't getting injector pulse.... possibly module in the dist.

mrrman

The Ecm was changed, it made no difference

mrrman

I changed out my fuel pump again as suggested by friends and the results are still the same. I was told that maybe the problem is with the knock sensor. What do you think? I am waiting for my OBD1 cable to arrive so I can hook up my code scanner. Any thoughts until then? Thanks

BlackenedBird

iTrader: (5)

All you need is a paper clip to read OBD1 codes.