No fuel from injectors, fuel pump?

[vegetaki]

Hey everyone, I've got a small(i think) prob. As the title says my fuel injectors aren't firing...at all. They are getting power an everything else works, spark, fuel line pressurized, turns over, etc. but no fuel Would a weak fuel pump cause this? I tested the fuel injection relay an its fine, so the tests said. The ECU gives me a couple codes sayin the sum sensors in the MAS is bad, so I changed to a 2g an still same story. I couldn't check for the codes while @ normal opporating temp cause it won't start. Anyway, if anyone has sum ideas on things to check, I'd greatly appreciate it.
Thanks,
Jason

 

[DrHess]

What's your fuel pressure at the rail (key on and cranking)? If you are going to work on EFI cars, you need a fuel pressure guage. They aren't that expensive at the auto parts stores. I would ball park guess the pressure should be around 46PSI, which is about where most systems run, but others with more DSM specific knowledge may know exactly. If it is 10PSI, that's bad and could be your problem, either the pump or the regulator. If it is 46-ish PSI, I would say you have an electrical or computer problem.

Some computer systems won't fire the injectors if they detect a major problem. Don't know about yours. I would fix whatever the codes you are getting (after checking pressure) and also are you sure you are getting power to the injectors? How do you know? Do you have a noid light? These plug into the injector harness and tell you if the injector is getting the power to fire. I use a multi-meter, but the noid lights are easier for the inexperienced.

Dr.Hess

 

[vegetaki]

The problem started since it first started gettin cold(I'm back in nebraska now). Week after week, it took longer an longer to start, that's why I thought it mite be the fuel pump. Once it got warmed up, she ran fine, but it won't start now. I haven't checked the pressure in the line but I will, jus kinda wonderin if a weak fuel pump will cause this. I haven't put a multi-meter on the injector wires(working all alone on the car) but I have used a test light on each one an it's on all tha time, before cranking and during. I tested the resistance on each injector an they're all good as is the fuel injection relay. I replaced all the caps in my ECU so I'm hoping its not that(circuit board looked fine). I know my way around the car pretty well(rebuilt the engine 10kmiles ago an do all my own work), but electrical probs are very annoying 2 me. So I guess don't be too concerned in whether or not I'll understand sum termonalogy(sp?)
Thanks again,
Jason

 

[2.4 turbo Hyped]

Please fill out your profile.

Is your cas working?? It makes the injectors fire at the correct time. Is your fuel injector relay working?

 

[vegetaki]

I know what the CAS does but I always thought, an was told, that if the cas was bad, you won't have spark and fuel, not one or the other. I could be always be wrong though nething can happen, it is electrical. I have tried testing it how the manual explained an as far as I know it's fine. But I wouldn't think that the CAS would start to act up once it started gettin colder. My last one jus went out like a switch(in summer), no if an or buts about it.

It makes the injectors fire at the correct time.

As the title says my fuel injectors aren't firing...at all.

Is your fuel injector relay working?

I tested the resistance on each injector an they're all good as is the fuel injection relay.

*not tryin to be a dick but if ya want to remind me to update my profile(moving back to houston in feb neways), at least please read the whole posts for ?'s that have already been answered*

Jason

 

[ADrewzki]

Just because your last cas went out a certain way doesn't mean that the one you have now will go out the same way. Just take it off the head and rotate it by hand. You can listen for each injector to hum and it takes all of 5 minutes. You can also check the voltage from the CAS as well just to make sure it's outputting 4.3-4.9Vdc. It's yet another thing you can eliminate while troubleshooting so don't assume anything until you have sufficient proof to discredit it. Saying that your last one went out a certain way is not proof, it's speculation.

 

[vegetaki]

The ECU is in charge of the injectors, not the CAS. All the CAS does is send pulses/info about piston position, to the ECU and the ECU then determines when everything should fire(fuel, ignition, etc.). If there is anything wrong with the CAS and the ECU is fine, then a code 23 will be recorded/sent and you most likely wouldn't have fuel AND spark. Since I don't have a code 23, the CAS is fine. Turning it and the injectors "huming" also verifies this along with the spark I have. I have searched for bad ECU symtoms and mine are right on par with others. The codes I'm receiving and no fuel seems to be the norm with ECU's goin out, plus with the extreme cold and heating up it's had to go thru lately, hasn't made its life any easier.
Thanks for all ur help with this,
Jason

 

[BoostedAWD91]

Check the fuel Filter to make sure its not clogged. a clogged fuel filter will keep gas from getting to the injectors

 

[vegetaki]

ECU was the prob, popped a new/good used one in and away she went