Hey so I have a 1987 camaro 5.7L tpi and we were testing out a horn to see how it sounds, we then were taking it off and took off the positive cable while the car was running and it started sputtering and then finally died, well fast forward we find out we aren’t getting fuel pressure, and cannot hear the pump prime, we started diagnosing and we have 12v to the fuel pump relay, our fuse near the battery is good, I jumped 12v to the g terminal to the ALDL and the fuel pump turned on and I could smell gas in the engine bay. But when I put a test light at the green and white wire there is suppose to be (from what I saw on big lou’s troubleshooting) power for two seconds when put in the ON position, I do not get that, if anyone can confirm if this means it’s my ecm or not that would be very helpful, thank you

 

Check engine light lit when key is turned to accessory position ?

 

I think Tuned Performance meant key in On position.

To clarify, did you say you disconnected the vehicle's battery cables to the battery while the engine was still running? Doing so can destroy electronics. The battery does more than store power to start the engine or power accessories.

 

the check engine light coming on is a indicator that ecm is powered up.

 

yea I know pretty dumb of us to do that, we disconnected the battery while the car was running. Sorry I didn’t respond sooner I didn’t see your messages, thank you guys for responding, tomorrow I will check if the check engine light turns on when I put it in the “on” position, from what I remember from today is that it was on for a couple seconds and my brother pointed out it was off after, I will double check tomorrow.

 

I will have to double check tomorrow I believe it was on for a bit when put in the “on” position but then it turned off, I remember my brother pointing it out. I will let you know tomorrow morning, thank you for responding

 

Okay I actually came out to check right now and the light that came on for a couple seconds then turned off was on the bottom left of the gauges, I don’t have my plastic trim that goes on the gauges so I just see the light, and on the bottom right there is a light bulb but the light doesn’t turn on, from what I believe is that the bottom right light would be the check engine light correct?

 

Man you guys won’t believe it the car runs, I don’t understand why it’s running but after I plugged in the computer correctly i heard the fuel pump and thought “this is new” and so I closed the switch waited a while flipped it back to “on” and heard the fuel pump again as well as had the check engine light on, I decided to crank it and it turned on after about the second try, I don’t understand what did it, was it disconnecting the computer and then reconnecting it after?

 

Hey guys just a quick update the car doesn’t turn on again, it ran just fine this morning and I decided to come back to see if it runs and it doesn’t , fuel pump does not prime, if anyone would have any idea as to what happened I’d be very thankful for a response

 

You'll need to answer Tuned Performance's question regarding if the Service Engine Soon light is on, when the key is turned to On, when the car won't start. The Service Engine Soon light is located to the right side of the instrument cluster panel. The left side light you noted might be the Fasten Belt light. Assuming the bulb works and the wiring is good, if the Service Engine Soon light is not on when the key is turned to On then the ECM is either not powering up, has a major fault, or there's a bad connection.

 

Yea the service engine light does turn on, just now the fuel pump does not prime, and I was able to get it started without the fuel pump priming?

 

Check for 2 sec power at the ecm a1.

https://tpiparts.net/1227165_pinout_diagram

 

Okay thank you for the diagram, just to make sure u want me to check a2 and not a1?

 

Check a1

 

I will be checking the terminal today with my dad, we recently found out that our return fuel line is actually cut, I don’t know when it got cut, I think it was when we were checking the fuel pump. Will be replacing that on Monday because I ordered in a hose for it, stupid question but would that affect the fuel pump priming? Thank you all for your help I’m sure I’m close to solving this problem.

 

No, it would not prevent the ECM from priming the fuel pump or running it when there's a signal. There is no feedback of any kind on the fuel pump such as any pressure sensor, etc.

 

Sorry guys I had to work and didn’t have time today, I would go out right now but my said I gotta wait for tomorrow morning, I will update you guys tomorrow

 

I’d just like to make sure I test the ecm correctly, I am planning to use a test light and just test terminal a1 with it, is a test light sufficient?

 

Correct, if it doesn’t just verify the grounds , constant hits on the ecm and accessory power.
if all that’s good is suspect the ecm being bad.

 

So I just tested the ecm I have no power at a1 when key is on, at b1 the test light turns on so I know it’s working I believe b1 is 12v for battery

 

B1 & c16 are hot always, a6 is accessory power . Sounds like the ecm could be bad.

 

I understand I was just trying to say I’m sure the test light is working basically, I will do more testing, and possibly just order the ecm.

 

There's not a lot more to it. To be clear, you won't see constant hot power on the A1 connection unless one of the following:
1)The engine is running
2)The engine is cranking
3)The ECM is seeing ignition pulses (with engine running or cranking)
4)Within the first 2 seconds of key on.

Simply connect the jumper end of the test light to a good ground and then connect the other end to the A1 connector. Turn the key to On and the test lamp should light for 2 seconds then turn off. Trying cranking the engine and the test light should light. No test light in those cases indicates the ECM is not powering up the circuit (ECM fault or ECM power/ground issue), you got a bad test lamp (easy to verify on a known good circuit) or you got a bad connection with the test lamp (another easy issue to resolve).

 

Yea the test light works I will attempt to crank and test a1 will let you know the results, if I get a replacement ecm would I use the stock prom or should I purchase another prom

 

The prom doesn’t go bad often. I’d reuse your existing one.

 

I got nothing at a1 or a6 while in “on” position and while cranking

 

will do thanks

 

Need to go to c207 a clear body connector next to the ecm check pink/blk wire for power key on and ecm fuse as well.
a6 is ecm power to turn on the buttery feeds to ecm are for keep alive memory.

 

Alright also I believe you mentioned some grounds to check which ones should we check?

 

All the grounds ate listed I the pinout and go to the back of the cylinder head passenger side. But if ecm is not powered that’s a concern.

 

I get power at pink and black on c207 connector

 

At pin f ?

https://berlinetta.info/C207.htm

just not at a6 ?

you might be testing c221 not sure.

 

I retested a6 and got power there and also I retested a1 at ecm and at the relay and got power for two seconds 😐 i may have tested things wrong because it was just me by myself

 

So now since I believe everything is good we will be replacing the return fuel line tomorrow and see if it turns on after that, thank you guys for helping me really appreciate it, first time posting here 🙏🏽

 

Like I said previously, your cut return line will have no relevance to your fuel pump not getting power or priming. These cars do not use any feedback system on the fuel pressure. The ECM doesn't know or measure fuel pressure so it has no factor in your issue.

You previously said it was running, then not running, then running, and now not running, etc. So you've obviously got an intermittent issue as one factor. Obviously, the fuel line would need to be repaired but if it "fixes" your fuel pump run issue then it's only a coincidence.

 

Sorry when I said “we will be replacing the fuel line and see if it turns on after that” I meant we are gonna continuing running tests with cranking the car and possibly getting it to actually run without the thought of fuel leaking. The fuel pump also primed today.

 

It primed after checking ecm, relay, and the c207 connector if that information helps

 

1 more update, I just went outside to check if it primed and it did, I will let you know if it does tomorrow.

 

If it's intermittent, you've got a connection issue or possibly a faulty ECM. Electronics can do weird things when they're broke.

Note, the fuel pump will not prime every single time you turn the key to On. For example: You turn the key to On and get the fuel pump prime (due to ECM powering the fuel pump circuit) for approximately 2 seconds then you immediately turn the key to off and back to on. The fuel pump prime will not occur in the second round. You must wait X amount of time with the key in the On or Off position, after the last fuel pump prime, before it will prime the fuel pump circuit again. Therefore, you can't keep turning the key to On, Off, On, Off, and see the fuel pump circuit prime each time due to the "timer" function.

 

I believe it could possibly still be the ecm, since it’s priming I’d like to see what happens once it turns on and runs and if it will turn on afterwards, also would like to see if it primes again tomorrow