HardcoreRM125

I have a 95 LT1 Z28. The injectors are not functioning rite and i am lost as to what to do. It was totalled and the engine was pulled to fix the frame back in 96, I installed the engine , everything else on the car is functioning besides the injectors ... Here is what i know

- Only has 13 thousand miles on it.

- The car has sat since 96 with fuel in it.

- I was going to syphon it but cant get a hose in, so i added 6 gallons of 93 octane, dry gas, fuel injector cleaner, and the water removal treatment.

- It has a brand new Delco Fuel Filter

- It IS getting 45 PSI at the Schrader with the key in the ON posistion, which is an acceptable value for an LT1 which should have between 41 and 47 PSI ...

- It IS getting plenty of spark, it fires up INSTANTLY on starter fluid and will run as long as I continue to spray it in the throttle body.

- The plugs for the injectors ARE in the correct places, theyre all numbered by cylinder so...

- I attached a ground strap from the firewall to the back of the intake ( Chevy Dealers suggestion )

- Had a Noid Lite on #2 ( As it was the easiest to unplug ) and in 4 to 5 seconds of cranking , the following happened. It flashed Dim once or twice , then the flash brightened for a couple flashes, then went out.

- I checked All the injector plugs with a voltmeter and all of them are getting 12.2 Volts.

- I checked the plug portion on the injectors with an Ohm meter and they all read 12.2 to 12.3 Ohms of resistance. My Haynes manual calls for between 11 and 14 Ohms so this is acceptable as well.

- I held a large screw driver up against the metal portion of the injector while my Dad cranked it, I had my ear against the other end and heard ABSOLUTLY NO clicking or any sort. I tried this for a few of the injectors.

- The car is throwing a SES code ( Which may be related to me not havin all the plugs hooked off for the lights ( Front Nose is off )) but I dont have a scanner, nor can i have the car towed to my cousins shop to check it on his computer.


If the injectors are clogged from sitting with fuel in them , can that cause this?

This is driving me insane and there is NO WAY all 8 injectors are bad with only 13K miles. Also I cant see the PCM being shot because it also only has 13K on it, and it seems to work fine with every other funtion. Does Anyone have a suggestion? I am willing to try jsut about anything, Please help ...

predator

maybe from sitting so long they got laquered up when gas sits for a while it will turn into a laquer

craigffb

Pull the fuel rail and check the injectors. It's not that much work, and you can see if they are OK.

joeSS97

Yeah I would take out the rails,see what they look like.Try cranking it a little,see if they spray.

HardcoreRM125

Would that cause them to not click tho with a screw driver up against them ? Also could that be why the Noid light took a **** ? Thanks guys

predator

if they are laquered it is like a glue for say and if they are glued the pintle may not be able to open to spray the fuel if you have power to them they shoul open also take them out and hook a direct 12 volt supply to them negative and positive and see if they open you should here them click when you touch the jumper wire to the terminals while open you can clean them better also

HardcoreRM125

I rechecked all my grounds ... their fine. However, the injector isnt getting the pulse from the computer ... Even if it isnt opening from being all laquared up, the actual plug would still flash a noid lite, and it isnt flashing ... I just rechecked it on a few of the plugs and no flash when i crank it. So what would you guys suggest ?

HardcoreRM125

Also, i DO plan on removing the injectors as soon as i can at least get the pulsing ground signal from the PCM ... what the hell could cause this ?

fireman

Okay, its your injectors.

My injectors sat for a year while the motor was out. When it was done I tried to crank the car and it would not start. Gas would leak out of my Y pipe connection. I replaced the injectors and WHAM, the car fired right up. I honestly didn't think it was the injectors, but, it was.

HardcoreRM125

I figure the injectors probly will need cleaned/replaced , but they still arent even getting the ground pulse to open them. I will pull the injectors once they are getting the ground pulse to open them if it still doesnt start. At this point they dont have the ground pulse to open so it might turn out to be a waste of money at this point if i dont need 8 new injectors.

Also ...


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Have you tried to start it with maf disconnected, or tps??
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No, didnt disconnect anything before trying to fire it up.


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Real quick see how much voltage (in millivolts) you have at the tps ground(black) wire. It should not excede 10 millivolts w/key on.
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Just checked it, with the Key ON it was reading a steady 19.3 mV Any suggestions as to which grounds you would check first ? I no the two on each side of the Rad are fine.


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there is a set of grounds on the drivers side that bolt to the trans via double ended bolt. i know my dash would act funny when theese were loose.
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If you could, can you give a better description of where ? Ill try and find it later, i looked while i was under the car and didnt see it, maybe the M6's dont have it ? Was yours an A4 ? And all my interior lighting is fine.


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Swapping out the computer is a quick way to see if thats the problem
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As of right now I dont have access to one, but am trying.

JOE96Z28SS

Check to make sure that the injectors are getting their Refrence +12 you can't test the Negative pulse with a testlight I tested mine with an LED with a resistor it's one of three things Injectors, PCM, or wiring

HardcoreRM125

Every injector had 12 volts to it, and they all read 12.3 Ohms resistance, so id imagine the injectors are fine, jsut not getting the pulse ...

HardcoreRM125

Also, what type of resistor did you use? Im kinda new to all the electronic controlled stuff on this car, so could you explain how you tested for the negitve pulse? When we had a noid light hooked up to it, it wouldnt flash as we cranked it, But all of them are getting the 12 volts i am positive , doubled checked every plug ...

S8ER95Z

Just throwing this out there.. Have you checked the harness to the Opti from the PCM. Ive heard of those going bad or just not being connected properly. ?!? Good luck

HardcoreRM125

Yea ... Opti , suprisingly, is fine ... Its gettin spark, it fires up INSTANTLY on starting fluid, and it was installed right so ... Im kinda clueless on this one ... Im gunna try to get it on a scanner tonite if i can ...