Hello all,

I bought a 86 Camaro IROC 305 TPI about a month ago. I drove it to and from the shop to get it saftied and it had a rough idle and acceleration but still ran. I got it back to the garage and the next day wouldn't start. I've been now trying to get it to start for 2 weeks with no avail.
It cranks every time and starts for a split second if I give it some gas but dies right after.

Check engine light is on and I pulled codes. Got code 34 back so replaced MAF and both relays and now code is clear and no others present. Check engine light is still on though.

Things i have tested:
- I have fuel pressure 40psi and it holds maybe drops a few points but holds for 20-30 minutes. I can hear the fuel pump prime as well. Replaced the fuel filter for good measure
- Injectors read 16 ohms and all wires light up when testing with the noid light
- Tested and pulled two park plugs I got spark on both that i tested (maybe it would be worth replacing the spark plugs anyways but the plugs/wires/rotor all look new)
- I need to pull all my houses off to check but feeling around and visually nothing is cracked or broken
- Sprayed starting fluid into the throttle body multiple times and it wont start

Things i have replaced:
- oil change
- fuel filter
- battery (tried with another newer battery and didn't help) also fully charged the old one
- ICM - ignition coil next maybe?
- temperature sensor
- IAC
- MAF sensor and relays
- fuel pump regulator
- air filters

Any direction or help would be appreciated.

 

So you replaced the MAF and no more code 34, but CEL now just stays lit up all the time and no other codes? What kind of MAF did you get for it? These cars can be very picky about them and seem to work best on factory Bosch. If the CEL stays on constantly that could be a sign of a failing ECM but the car doesn't seem to run long enough to see about this.

Have you checked the TPS sensor voltage? Should be at 0.54 with key on, engine off and throttle closed. Very simple to test with a multimeter and a jumper wire and if you do a search you can see the max voltage at wide open throttle, voltage should also move smoothly with the throttle changes so verify the voltage changes when opening and closing the throttle. There is a nice Youtube vide by a guy called Jrobling that shows this as well.

I also wonder if you have weak spark, have you checked out your distributor more closely? Maybe a failing pick up coil? If the ignition coil looks original that might be another thing to test or just replace.

 

Yes correct CEL is lit all the time and no other codes (other than 12). I purchased a Delphi MAF.

I have not checked the TPS sensor voltage i just replaced it. I will check the voltage tonight.

I have pulled apart the distributer checked all the connections check the rotor and replaced the ICM. I didn't ask the previous owner but all these parts look new but maybe its worth the 50 bucks to replace the coil.

 

So when I replaced my TPS on mine a few years back I did the same thing just literally pulled the old one and put a new one on...car ran like crap and then I watched that video and saw that once you install it you have to set the voltage at 0.54 by adjusting the position of the sensor or the car will run pretty bad. That sounds like what is going on here maybe and is what I would do and then change the coil as preventive maintenance. You've replaced or tested most of the usual subjects.

Delphi MAF is the best you can get that is new IMO so you should be good there unless you got a defective one. Seeing as how you get code 12 the ECM seems to be functioning properly.

 

Thanks, found that video and will follow it this weekend. I will pickup a coil and swap the plugs just for good measure if the TPS adjustment doesn't solve it.

 

Sounds good, just be aware that a replacement coil will need to be mounted into the bracket that is on the factory coil( if still equipped, if not this is moot) so you will have to drill out the old rivets and either replace or hit the hardware store and get some bolts and locknuts to secure it back so the coil doesn’t just bang around.

 

86 is coil in cap , for what it’s worth

 

So he won't have to mess with rivets etc. I thought his setup was like my 88'

 

Yup coil is in cap I have had the coil out to take a look already so ill be all good to replace it. Thanks guys

 

Update: Got it started Sunday after cleaning up some of the terminals and adjusting the TPS and was running pretty well. Idle was a little high but my tach is off so have to get that sorted. Was pretty happy until I went out on Monday and it was a bit tougher to start. It has gradually gotten worse until today when it will not start again. Any thoughts on why it will gradually get worse until back to square one over this week? My o2 sensor wire is busted so have a new one on the way but it was running without it connected so not suspect on that. Any thoughts would be great.

 

That oxygen sensor can cause some problems so I will be interested to see what a new one will do but other than that I am at a loss.

 

One other idea crossed my mind, I wonder if the ECM is broken or if the connections are all solid? Might help explain the constant CEL. Data scans would be nice here so you can see what the computer is seeing.

 

Okay thanks ill pull out the ECM and make sure all the wiring looks okay. I don't have much experience with data scanning so ill take a deeper dive into that. Appreciate the help.

 

If you are looking at an inexpensive way to see live data on these cars check out 1320electronics.com he has a Bluetooth adapter that you can run on a android device. For under a $100 you can save yourself a lot of time trouble shooting. Another member recommended this to me and it has saved me a lot of time guessing.

 

Unfortunately it looks like they aren't selling them anymore or they are completely out of stock. All listing say out of stock and and there ebay store is empty looks like ill have to find an alternative. Looked like a solid product though.

 

I had the same problem, ended up going with a Moates ALDU1 and CABL1, my phone has a USB-C port so I needed a USB-C 3.1 Type C Male to USB 3.0 Type A Female OTG Adapter, and then I bought ALDLDroid off the google play store and it worked without issues. Still messing around with it but that's an in-stock alternative. The Moates stuff seems to be quite high quality.

 

Thanks @Komet ill look into that.

 

Update: o2 sensor changed (pain in th a** by the way even with the tool) no response i also pulled the ECM and its a Delphi so it must have been replaced at some point but it looked good traced the wiring harness and all the connections looked good.
I then found another post of someone having similar issues and he took out the spark plugs cleaned them and set the gap and cleaned the injectors. I figured id start with the spark plugs I checked for spark previously but i pulled four of them and cleaned them reset the gap then installed them again. It kicked in right away and ran for about 30 seconds then died. I decided to pull all 8 and replace them and it started right away and has constantly started and ran for the last 2 days. Even the idle is steady. Drove it around the block and its not stuttering in first and second anymore either.
I have to check the timing and reset my IAC and TPS again and figure out why my check engine light is still on but I think were back in action. I'm sure all the other stuff i replaced helped as well. Thanks!