My 91 firebird will crank but wont start. i can get it 2 start with ether down the throttle bidy but it'll only run till its all burned up. i have fuel pressure(47psi), spark and compression. when i pull the plugs, their completely dry. the car was runnin fine and just 1 day it crapped out on me. i knew my timing chain was bad 2 begin with but now its another problem. the fuses for the injectors are fine. could i b losing power 2 my injectors???? plz let me know if ne1 has an idea of wats wrong wit my car.

 

You have to get to the injectors and measure the resistance of each one. Should all be close to 13 ohms and all very close to the same value. If not they need to be replaced. Southbayfuelinjectors.com have a good set for about $120.

 

i checced 4 resistance also. they all ohmed out at 12.5. the specs call for 12-16 ohms of resistance.

 

there is a fuse holder located on the fender or behind the headlights near the battery , check that fuse, its the main fuse for the ecm.

even if it blows out the car will still have spark and the fp will still come on

 

the fuse holder on mine is on the passenger side of the car, opposite side from the battery. that fuse is fine though. do u think it could b the ecm burned up or the prom inside?

 

i hate to tell anyone to do this cause its very dangerous, but u can pull the fuel rail and injectors out and hold them so u can see if the injectors spray and then have somone else crank the car over to see if they are working.

again this is extreamly dangerous alls it takes is one spark or flame and uve got a big fire in a hurry so if u do test it like this be very very very careful and have a fireextinguisher on hand

if the injectors dont pulse then u can start tracing back the wiring to the ecm and see if there is a break in the wires somewere

also check the 2 inj fuses in the fuse box well do this first

 

Is the security light on? Sometimes when theres a problem w/ the vats, it'll shut off the injectors right after it first fires up.

 

What you describe sounds most like bad injectors so check them as soon as you can. One bad injector can cause the ecu to shut them all off.

 

Need to pull codes from the ECM and look for a code 46... VATS won't allow the engine to start PERIOD if there is a problem as the ECM disables the fuel injector pulses when there is a code 46 present.

 

definitley seems like no pulse from the injectors. X2 on VATS

 

actually i had vats go active on me cause the wires broke up in the colum on my 89, if u try to start the car and then leave the key on for 2-3 mins then jump the starter soiliniod with a screw driver to crank the motor it will fire and run.

thats how i got my car started so i could get it hom and put a resitor inline to fix my car

 

i have no way 2 hook it up 2 a scan tool 2 pull codes. i dont need 2 pull the rail, i know the injectors aren't spraying. when i pull the plugs their dry. i have good fuel pressure but it'll only start wit ether and only till it burns that up. the only thing i think i can really do wit my limit of diagnostic tools is just checc for voltage at the plug 2 the harness for the injectors. if ne1 else have ne other ideas plz let me know. i appreciate all the help. i just know its gonna b something little that im over looking.

 

Check the net for pulling codes, its called the paperclip trick.
If its a vats issue, can you try another ign key? Is the security light on? Does it come on at all?

 

I've done that where it'll make the MIL light blink, i'll do it again 2 double checc though, but idk how it'll b my VATS system cuz i've disabled it a long time ago. when my car wouldnt turn on wit the key, i replaced the ignition switch but it still wouldn't start wit the key. so i bypassed it and the key turns on the ignition still but i have a button 2 turn over the engine. i haven't messed wit the car since Thursday, i'll b working on it again Monday. there has 2 b something else keeping the injectors from spraying. i know my cars gone through a few ecms b4 but i neva had this problem b4 due 2 it. the security light isn't on either though. b4 the car went down though, it was acting up. sometime when i drove somewhere it wouldn't start bacc up after i shut it off until it sat 4 a few minutes.

 

Your really need to at least measure the resistance on all the injectors. Even one bad one will shut them all down. It's a relatively easy thing to do and nothing else matters if you aren't starting with known good injectors.

 

the injectors were one of the 1st things i tested. their all ohmed out at 12.5. manufacture specs call 4 12-16 ohms of resistance

 

You could maybe try a noid light to see if there's anything at the injectors and work back through the wiring if not.

 

im gonna try 2 c if i can get a set of noid lights. thanks 4 the help. i'll let ya'll know how it goes. let me know if y'all have ne more ideas of wat this could b.

 

im getting voltage up 2 my injectors. wat could b my problem???

 

You may need to remove the injectors and get them checked, cleaned etc. Even if they're getting the right signal they could be clogged but you say the car suddenly stopped working. It would be unusual for all the injectors to clog at the same time and you'd more likely see a slow deterioration.

 

I your 1st post you said something about a timing chain problem, whats going on there? If it jumped tme, not only the cam timing will be off, the ignition timing aswell.

 

The thing that argues against that is he says it runs with starter fluid sprayed in the TB so it still sounds like a fuel issue. 91 you may need to pull the injectors and get them checked just to be 100% they are not the issue. Other than checking the resistance and/or trying the spray (and pray!) test described above there's no other way to test them.

 

i got all of the timing fixed already its just either an electrical problem or fuel. i dont want to buy a new set of injectors cuz wat if thats not the problem? idk where i would go 2 actually get them tested better.

 

I was "lucky", mine had bad resistance values so it was a no-brainer. I looked at getting them checked/rebuilt locally but I got the 15# set from Southbay for less than that was going to cost! Unfortunately you have to know for sure they work one way or another. Unless you can pin down some other issue I can't think of a way around eliminating the injectors as the cause.

 

i finally got a chance 2 hook up a scan tool. i got a code 46. how can i bypass the vats???