Hello.

I have a 92 Camaro, that has been sitting since 4 of 04, or longer, but that was the last time it was legally registered. It has a no start condition, and found that the fuel pump wasnt coming on. I replaced the fuel pump, and can hear it come on, and I have fuel at the throttle body. Still no start. I then checked for injector pulse, and have none. I was told that this car ran and drove when it was parked. Ive considered that it could be the pass key, so Im going to stop by my local radio shack and pick of a resistor and try to bypass the bypass. Is there anything else it could be? Any usable input would greatly be appreciated.

Thanks

-Bill

 

'k4u

Check and see if you have spark during cranking. If you have no spark chances are that either reluctor coil or ICM inside dizzy have gone bad.
If either one is bad ECM will not see DRP pulses and will never fire injectors.

//RF

 

i do have spark, it will run all day providing i add fuel at the throttle body. The only thing im lacking is injector pulse.

 

Check the fuse(s) that power the injectors.
You should have 12 V on both sides of the injector with key on.
The ECM grounds the injector to fire them so power will be on both sides until fired.

 

Yes, both fuses have 12v on both side with the key in the on position. Im leaning towards the theft deterent system, as its the only thing I can find that withholds injector pulse....this is wearing on my nerves though, thats for sure

 

You should have 12volts on both sides of the injectors, reread above

 

i have the same problem .. no pulse i dont hear my fuel pump relay tho
will that allso control my pulse ?

 

Sounds like the ignition module under the distributor cap.

 

Been a while since I messed with this but if it is the key resistor VATS, I believe the Vats knows what the resistor value is.. I believe the resistor values are different for each. Do you know what resistance to shoot for? Heres a good thread with the resistor values used. My memory is telling me that if it is a VATS problem it won't even crank but i could be wrong...Secuity light would be on also I believe.

https://www.thirdgen.org/forums/elec...light=resistor

if the link doesn't work just use search and "resistor". Title is VATS PROBLEM.

 

i can almost promise you it is the vats system. i had this problem when i put a 91 corvette into my fiero. i got a chip burned with the vats taken off from pcmforless for $100 and it fixed the problem.

 

I just worked through the vat issue on my 89 iroc, it would not crank over till I bypassed the vat with a resistor.

 

i too have an 89 IROC, i am having the same trouble, i have fire to the plug, fuel pump is primed and at rail, i have a resister bypass on the column. but no injector pulse...i tested to make sure the resister was correct by taking it off then attempting to fire, pump didnt come on and it wouldnt turn over, so its not the vats right???? how could the vats not work but tell the fuel pump to turn on and turn the engine over???? im at a loss...

 

check tps voltage.anything over about 4v cranking.....clear flood mode ...no pulse

 

Checked tps, c wire (gray) over 4v so what does this mean, what do I to fix whatever prob this is??? Please help, they are all over 4v if u check different way...?? Please help

 

the majority of no start conditions are ICM related, at least in my opinion... ...

 

i believe "b" is the signal wire if thats over 4 volts then you have an issue w/tps.just unplug tps and see if you get pulse.if you do tps is bad.if not probably is bad ign. control module.but since your getting spark more than likely ecm is getting rpm signal from icm.

 

also is this atbi or tpi car?how are you testing for pulse?shorted injector windings can shut down inj. drivers in ecm.does the cel work?

 

My prob is that my blue and gray wires are crossed in the harness somewhere! Lol, the simplest things are sometimes the worst problems....

 

i have the same problem with a 91 z28 i have.its been in storage since around 2000. last year i tried to get it running with no luck.with all the gm diagrams i started trouble shouting.it seems to me crousion is the biggest problem. my fuel pump wouldnt kick in,replaced it and it got me fuel presure.still no go.checked all computer wiring, all seem good.the injectors wount fire.the computer needs a pluse from the distributor to fire the injectors.the pickup coil generates the pluse as the engine turns.this seemed to be my problem.

 

Vats malfunction will NOT even let the car crank. If the engine cranks then vats is fine. Vats problem will almost act like the battery is dead and won't engage the starter. The ECM gets a signal from the ignition control module in the distributer to pulse the injectors

 

I have the same issue and I just replaced the ICM. Currently I have power to the Fuel Pump Relay, but the FP wont "buzz" unless I jump the orange to grey wires, but I have tried 3 other relays with no resolve.

-I have spark
-The engine runs with starting fluid
-Fuel Pump only works with jump
-Fuel Inj. Fuse ok (All fuses ok)

 

Relay?
Low Fuel Pressure?
Restricted fuel filter?
contaminated fuel?

My grounds were last checked 2008. Possible injector ground issue?

 

Thank you for the reply! I will share my thoughts and please feel free to comment:

-Tried 3 different relays....I'm not sure that's the cause, but it doesn't explain the fuel pump issue.

-I was thinking of installing a Fuel Press. Gauge in-line...maybe it's time

-My next step was to replace the filter, but since the Fuel Pump issue was still pending, I was going to wait (thoughts?).

THe fuel in the tank is as new as yesterday. Tank was low so I added 5 gal.

 

try to reset security by turning key to on position let sit until locks are active

 

Any updates on this guys?? I recently bought an 87 iroc with a 5.7 tpi in it and the car has been sitting since 06 and it sounds like ive got the exact same problem and cant seem to figure out whats wrong?😕

 

I think I narrowed it down to the pickup coil was gone. Fuel pump to. When the pickup coil goes, the distributor doesn't send the voltage signal back to the computer, and the computer in return doesn't put out an injector pulse.

 

You sir are my hero!! washed my engine and pulled my hair out when it would not start. This was my issue.

 

I have a similar issue. 1990 Camaro 5.0 TBI. Vats was bypassed. Unusually not with resistors. but with a key. I bought it that way. Ran up until about 6 months ago. My driver side injector drips, not sprays and my passenger side no pulse. There is also a fuel pump switch. cranks, fires. but lack off fuel wont let it turn over. can this be an ICM issue?

 

Will test TPS next.I tested the Harness to both injectors with NOID light. and theres no power. thanx for the reply

 

Hey im having a issue just like that n have a 96 corvette into my camaro ,,may i ask what type a chip did it burn n where is it located ?? Please if u can help

 

If your using a stock 96 ecm better to get a hz modulator from eBay or have the ecm flashed no chips to remove in that ecm.


https://www.ebay.com/itm/GM-VATS-or-...EAAOSwXQpeq1fC

 

It is that ecm ,,do u think that could be the problem

 

Lmao, yes that’s the ecm it’s dos based os.
thats not a lt1

 

What issues are you having no injector pulse and ideas on engine specs l98 ? Stroker ?

 

I have a 92 Z28 that has fire, does crank, fuel pump working and no injector pulse. Security light does not stay on. When in the on position the computer will not communicate with the scan tool. The cooling fans run also. I believe it is vat oriented but not sure. Also the voltage is missing on the crank circuit which is a 3 amp fuse. Car will run on starting fluid so I have fire. No blown fuses. Could this be the pass key system? Any help appreciated.

 

 

Please start a new thread, you will want to be more specific with your questions. What ecm is being used tpi or tbi or mpfi, fuel pressure and spark tested. Has it sat for along time. Old icm or no tach signal. The more information given the better everyone can help.
no communication to the proper scan tool or not blinking codes and fan on koeo is a sign of a bad ecm.

 

You should start your own thread in the TPI section and not the DFI and ECM section.

Does your 1992 Z28 still have its Rochester Products Multec fuel injectors that it came equipped with from the factory? If unsure take a well lit in focus picture of the two right by the throttle linkage on the driver side and post the picture in your new thread.

They are retroactively defective by design. The coil winding's insulation can't stand up to ethanol fuels, HEET, or fuel treatments that have harsh solvents. These will eat the insulation off the wire of the coil windings causing shorts. Disconnect all 8 fuel injectors from the wiring harness and measure the resistance of the coil windings of the injectors. Post the OHM readings in your new thread.

What scan tool are you using? Remember GM's OBD I ALDL port under the dash can't power up a scan tool by itself. It needs power from a cigarette lighter or the 12v battery under the hood.

The VATS interrupts the starter's electrical system and the fuel injector driver in the ECM. It doesn't do anything to the fuel pump or ignition system.

 

I have the same problem. Check your crk 3amp fuse. There should be 12 volts coming in when the key is in the on position and when cranking. If not and the fuse is good then more than likely it is the vat system. It sends a signal and tells the ECM to open and close the ground side of the two injector banks. You can have voltage at the injectors but the ground is the pulse.
My next step is a resistor bypass on the key but if any one has a better idea I'm open to suggestions.

 

if your offering suggestions do you have a issue that you need help with? Or just offering suggestions to a dead thread ?