I was searching up threads about fuel injection to see if there have been issues similar to mine. While I was searching, I found this thread by Intel where he was diagnosing a no-start after his Fiero had been sitting a minute. His issue ended up being that the timing somehow went off while sitting. Don't think that's my problem.

Some of the tests he did intrigued me though. I removed a spark plug to see if there was fuel on it after cranking for about 4-5 seconds. Pulled it out and it was bone dry. Not even a scent of fuel. After this, I poked the schrader valve and gas shot out.

So I have fuel pressure at the rail but I don't have fuel coming out of the injectors? That leads me to believe it's that the injectors are not getting power or they are plugged up

Side note: Anyone know if I tested the correct connector I posted above? I haven't been able to find any info on the injector harness. If I can't figure it out, I'll just remove the upper intake which I assume I'll have to do either way.

------------------
Jumpmonkey

quote Originally posted by cartercarbaficionado: ah the lovely crappy tbi injection. check fuel pressure and that the injectors spray at cranking speed, quick and dumb way to check pressure is to let it pressurize and then find the Schrader Valve and poke it with a screwdriver after you disconnect the coil on all sides, the fuel geyser should be around 4 to 6 inches tall. aka if it touches the decklid its perfect

His car is actually an MPFI-based system... 6 separate injectors with the injector directly in the intake manifold just before the intake port on the cyl head. Which... totally random here, but I've often wondered if there's any significant benefit to converting to an SFI system. Difference being, ours with MPFI, the valves have fuel that pools on top of the intake valve rather than being sprayed directly when the valve is opening. With SFI... it sprays each valve independently as the valve is getting ready to open. I don't know if this saves fuel, makes more efficient use of it, etc... but it's certainly a more modern take.

quote Originally posted by jumpmonkey: So I have fuel pressure at the rail but I don't have fuel coming out of the injectors? That leads me to believe it's that the injectors are not getting power or they are plugged up Side note: Anyone know if I tested the correct connector I posted above? I haven't been able to find any info on the injector harness. If I can't figure it out, I'll just remove the upper intake which I assume I'll have to do either way.

Just a couple of things...

I *THINK* you said you tested spark, correct? You said... "If" you could start it with starting fluid, then it should be fine. But I didn't get a concrete answer (or I might have missed it, and I apologize). If you're able to start it with starting fluid, then the problem is ABSOLUTELY fuel delivery.


Here, let's do it the way I know best... like a computer program.


IF Car Starts = TRUE when you spray starting fluid, THEN ECM and SPARK are OK. (EDIT: It would also mean timing isn't too far off)

IF Fuel Pressure = ~38-42 PSI at the schrader valve, THEN fuel pump is OK


If you can confirm both of those for me as TRUE (as written), then I think we need to take a closer look at a few things.

- Have you confirmed you don't have any engine codes?
- I'm thinking maybe plugged injectors?


... that is the right connector, and if you've tested both those wires and you see pulses, it means the injectors should be bank-firing (I'd need to double check, but I'm assuming those are the right to wires).

Does it feel like it's trying to start?

[This message has been edited by 82-T/A [At Work] (edited 05-04-2024).]

[This message has been edited by olejoedad (edited 05-04-2024).]

[This message has been edited by olejoedad (edited 05-04-2024).]

[This message has been edited by jumpmonkey (edited 05-06-2024).]