gravesjoey

I would drive the car and when I would accelerate quickly it would stumble. This went on for several short trips until one day it started fine, ran for about 5 minutes, drove it for approximately 1/2 mile and it stummbled and cut off. With the car still rolling I put it in neutral and it would restart. It did that 5 times once the car reached operating temperature it shut off and would not restart. It has now gotten to the point where it will run for 3-5 minutes before it shuts off and will not restart.
Pulled a scan...no codes showing, changed pickup coil, upper coil, distributor module, and ecm. Tested fuel rail pressure at 45psi while running. Once it shut off I bled the pressure and it still tested 45 while trying to crank and restart.

Any help would be greatly appreciated.

tehcarguy

My 86 is having sort of the same problem. After about a half mile of driving, the engine stumbles, and has no power whatsoever and it starts backfiring. I am getting a code from mine, though. Are you sure you're using the OBD 1 and not an OBD 2?

corvette95

I just went through a smiliar problem on my 89. Ran "decent" on start up, hotter it got the rougher it ran, to the point of missing, felt like two or three bad plug wires, BUT they were fairly new. I check the usual, has a broken MAT wire - with associated code, fixed that, still had problem. Now about three months ago, I had one bad injector, replaced the one injector, (PIA - L 98) , been racking my brain. finally said I am pulling everything and making sure every vacuum and fuel like is correct..etc. So I did, Made a homemad injector tester, including pattern spray flow etc. Before I tested the injectors by GM injector tester and ohming them, thats how I found the one bad injector which I do believe was only one bad injector at that time. ANYWAY, made me a homemade stand, had extra pump, pressurized rail, used my injector drivers and tested each injector by flow, ohm, spray... HAD FOUR DEAD injectors out of eight, These just went bad in the last couple of hundred miles since I replaced the one injector. So, get with FIC injectors here on the board and order you a set of EIGHT injectors, but do your own testing first...at least ohm your injectors. should be 16 to 17 ohms each,.

gsixl

When this happens are you getting any fire to the plugs? Sounds like you already suspect electrical problem. Sounds like you have fuel pressure. Possibly the injectors are not firing?

gravesjoey

Yes I have fire at the plug when it wont start so I'm going to omh all the injectors next. thanks

jfb

An ohmeter test of injector coils will only find gross coil failures. An ohmeter will not find a coil with a turn to turn short, but this kind of failure will not allow an injector to work properly. The only electrical test that will find ANY kind of coil failure is with an impedance bridge which measures the coil inductance and Q. I found one bad injector in my 87 vette this way. An ohmeter showed the same resistance as all the other injectors but the impedance bridge showed one injector with 1/2 the inductance and 1/2 the coil Q. I would do the ohmeter test, but keep in mind it isn't a very good test.

gravesjoey

I checked all the injectors and they all ohm out at 16.2 to 16.9 but number 3 cyclinder injector showed 2.2 ohms. So does this tell the ecm to shut the engine down and not start. Any help I'll listen to all.

corvette95

Hate to guess but you probably have three or four bad injectors even if only one ohmed bad

gravesjoey

So if one shows bad does this effect the problems I'm having?

Spinner_89

I don't remember the tests I went through to determine the error, but very similar complaints led to changing the computer chip. New chip = ran perfectly again !

gravesjoey

One tolded me to unplug the one injector that is bad and try to start it . It started and run up to opp. temp with know problem soon as i pluged the injector backup it stalled and would not start. What a nightmare.

corvette95

One bad injector WONT do that, one tested bad injector but 3 ,4, 5 etc bad injectors WILL! If you cant get any further, PM me and we'll set up a time to troubleshoot over the phone while your hands on with the car.

gravesjoey

Dear, CORVETTE 95 If you can and would like to talk me throught some steps please email me phone # that I can reach you at. (jangrav3@aol.com) thanks again.