First thing this is a great site lots and lots of information.I am new
and have been looking around for some time now.To all here thanks.
I hope someone out there can help me out.I have been trying to find my problem but im getting it could be this or this.My car is in a shop and they are having a hard time trying to figure it out.Have had it for some time.The problem w/ the car can't get it to start at all.it turns over and acts like it is not getting gas ejectors are not firing.Spray w/starter fluid and the car fires right up will run as long as you spray.Shop said they found 1 bad ejector and replaced.Still no start.The fuel psi at rails have been
checked ok,new module for distributor,cap,rotor,ecu,vacume leaks ok,fuel pump kicking on, shop says computer is not giving a code,The car just died while driving down the road.If all this checking keeps up its going to nickle and dime me to death.I seen here that the computer will not kick in until over 350 rpm.
That the distributor needs to send a pulse to pick up coil to ignition module to ecm.So do I replace the distributor?If injectors
are not getting power is it in the injector harness,bad wires
and if they are getting power then they should fire right?Looking
for some help.1991 Z28 350 TPI

 

Sounds like VATS problem.
Did they put a noid light on the injectors to confirm they are pulsing?
Have them check all of them for proper resistance as well.
If they are not getting power check the fuses and wiring.
Having power at the injectors is normal (on both sides) The ECM grounds the injector wire to fire them.
If it fires up when spraying, then you are not getting fuel. VATS will not allow the ECM to fire the injectors but "should" give you an indication. I think the security light or something comes on.
As another note, I've seen that you need to wait for "some" amount of time after a VATS failure to try again. Don't recall if it is greater than 30 seconds or not but seems like a good place to start looking.

 

Vats shouldn't stop the car while running, and I don't think it'll turn over either, but I could be wrong.

I'm still in the dark as to what exactly is and isn't controlled at what RPM, by the ECM and by the ignition module. I has some info on one of my threads, but I was also told it wasn't exactly correct. I'm not sure.

 

Hi!
My car died to on the road and wouldnt start after that,but i dont get the fuelpressure from the pump,(but the pump is going)but no bildup pressure, how high did the psi go under your testing?
I am hawing my pump removed soon.

 

Must have passed over the "just died when driving", your correct that VATS is only checked on startup. (some have crank disable, some do not from what I've seen)
Definate fuel problem but possibly pickup coil related.
I believe the timing control doesn't kick in until 300 rpm IIRC.
There are some temperature related SA adders/retards but I "believe" those are only active from the 300 up to the idle rpm.

If injectors are pulsing no need to look into the distributor, the pulses are getting there but would seem there is no fuel being injected.
A data scan will show reference pulses and the noid light should confirm injections are happening.
Scan would also confirm all sensors are reading where they should too.
One other thing is that if a reference pulse is detected, the fuel pump relay will engage for two seconds on each pulse. Might want to see if that is happening to confirm pulses.

 

You can alsoe losing the return fuel line and start the engine,if there isnt coming any fuel, the pressure are to low or stoped at the regulator.Or am i wrong?

 

Thanks for the replys.Securitylight comes on when ignition is turned on then goes off after a few seconds.Shop checked out vats took it apart.Psi took to 45-55-60 all held during cranking,also let gauge sit on for some time to see if any drop was none.The regulator does it come into play before or after the fuel rails?If the return was plugged shouldnt the car start at least for a few seconds to run out the fuel in rails?If return is plugged will it keep it from starting?Will have it checked out do not think this has been done yet.Will also make sure that a noid light and scan was done I think they did to.Noid light will go out if injector is working right?If light stays on or goes dim then I have a bad spot in wires for that area?Will also make sure the pick up coil has been checked out.If any help when the car died had to let it sit for 5 to 10 minutes had to crank it over several times then it would start would run really rough" like it was running out of gas" would make it about a half mile then would die did this for about 2 miles to get it home once got it home in the garage it was done. Whats the voltage for injectors 12 volts?

 

The regulator bypasses after the fuel rail. If return was plugged you would get real high pressure so I don't think thats where to look (right now anyway)
The noid light will not light until the ECM grounds the injector "out" wire. Then current can flow and turn on the light as it would turn on the injector. Having power on both sides tells only half the story. The power supply fuse is good if power is there (should be 12V).
Light should flash brightly each time the injector is grounded.
Hope that helps.

 

Shop has done all thats listed above,changed the pick up coil in distributor old one was pretty bad,once this was done the ejectors on the right side fire now,left side are not.Left side of ejectors noid light goes dim.Distributor has new module,coil,cap,pretty much all new now,think it would be a waste to replace distributor now?Checked out wires look good.Looking on replacing computer again.Getting a bit ahead i guess.

 

Check the resistance of your injectors should be in the 16-17 ohm range under 10 is bad and just 1 bad can cause it not to run and even fry the ecm after time.

 

was the injectors, just replaced them all w/ 24's car runs just fine now,this was a good one for me to learn on. Thanks for the replies.

 

Dan your post was right on "to bad i didn't see it till after car was fixed but thanks.