97 lumina, sudden stall and no start

[camaro383]

ok folks..lets see if this has happened before
I just purchased a 97 lumina LS 3.1L I drove it for a few weeks with no problems what so ever. Suddenly on Friday I started my car, drove a few feet and it stopped running with no notice. I tried to restart it but it will just crank...very strong crank, but no start.

I checked for spark, that is there.
checked for fuel pressure at the check valve in the fuel rail. that was good.
checked for fuel at the plugs from not starting...the plugs were dry.
I pushed the car into the shop and checked for any DTC's that might have been stored in the PCM. that was blank. with my scanner I checked to see what the Datastream would show while cranking. I found there to be two problems with the injectors.
1) the injector pulse was at 55.8msec (way out of the range of .8-4.0msec)
2) injector fault was set to 'yes"

with this problem I am assuming that I have a PCM problme and replaceing is necessary. But I wasn't sure and am not up to snuf on my domestic stuff considering I am an import tec at honda.
Any help or thoughts would be highly saught after. Thank you in advance.

-camaro383

[maxwedge]

More important here is what is the actual fp at the rail, and do you have rpms reading on the scanner as it cranks over?

[jonsonton]

Have you checked the resitance on the injectors? I think they should be somewhere between 15 + or - 2(I think??). Also, you check the fuses, I think there's 2, 1 for each bank.

[camaro383]

ok, a little more info with another day at the dealership. I checked fuel pressure at the rail...I have 45lbs when the key is in the on position. I also noticed on my scanner, after grabbing a service manual that I have the IC mode in Bypass and the Bypass mode is, well obviously active. from what I understand this will give me a spark, no ful injector pulse condition. Is this right, and if so, is that a PCM replacing situation.

My fuses are good, also checked my relay and PCM signal to injectors.

[camaro383]

To answer your other question, I do not have RPMs registering on the scanner when being cranked over.

[jonsonton]

Not to sound like an idiot, though I am, but what is IC mode?

Secondly, let's see how injectors work(on GM at least). They have a 12 volt power source and a ground ckt controled by the ECM which feeds off of various inputs such as the crank sensor, ECT sensor, etc... Could you act as the computer and ground the injector yourself by backprobing the ground wire on the injector with the key on. Maybe you could try that to see if the injectors have the ability to be commanded on. Or easier, you could cammand the injectors on through your scan tool.

Also the 55.8msec you got, would that be the computer controlled ground shorting to ground all the time? If so, why were the plugs dry?

I know this doesn't help any, but any more info you have might help.

[maxwedge]

Originally Posted by camaro383

To answer your other question, I do not have RPMs registering on the scanner when being cranked over.

Ok, either the ign module or cps is bad, or wiring to the ign module from the cps is open. On rare occasions the pcm could cause this, Have the module tested at AZ or Napa, but they may have to test it a couple of time to be sure. Look for corroded ar bad connections in those circuits also.

[camaro383]

that is what I was hoping to hear...I'm glad you were able to help me with this. I am off today and will have to see if I can get back to the dealership to test the mod. I am currious of one thing. what is it that I tell you in the info that I give you tells you this is the problem. I just want to understand. If this was a honda, I would be in heaven as far as diag. but I'm not the domestic tech I would like to be as the owner of this car. Thanks again. HUGE help!

[bigj-dog]

Simple check, I had a friend with a '96 monte carlo with a chip in his key, the chip was wore out and the ignition would turn and it'd crank over, but no fuel from the injectors. Try your spare key if you have a chip.

[camaro383]

ok, well a few days later...I have installed a new Ignition mod. Still just cranks over and no start. I still have a bad injector pulse. No, it is not the key...nice idea, but I don't have a chip in my key due to thefact that my lumina has an optional police ignition. (door key is the same as the ignition key) It ran with the same key before...so it is not a key related problem. I am still thinking it is a PCM problem. What do I have to do to get the new PCM programed for the car?

[soopacee]

crap....i had the same problem and i cant remember for the life of me what the part was called LOL.....im no car expert so that doesnt help.......it was some kind of fuel thing, not the sensor.....it was a small part on top of the engine that measures the fuel intake.........kinda like when your starting it, its not giving it its proper fuel to start it......crap i dont help at all HAHA.....hope it helps a little bit if you know what im talkin about


****i thought about it....it was a fuel pressure gauge***************