3 weeks into this and I have finally found something wrong...

Problem: No start and SO flooded I drained 3 gallons of gas and oil out of my crankcase when the starter would not turn it over anymore.
I am on my last psychotic nerve.

After weeks of diggin for clues, checking possible bad sensors, replacing ignition mod, plugs, cts, oxygen sensor and fuses, I finally found something that ain't right. The injectors!!

I finally got the nads to gutwreck the plenum and work my way to the fuel rail and see if any injectors were leaking or not working. I have 45 lbs of fuel pressure and no leaks until I turn the key on. Yep, when the key is turned on and the fuel pump runs for two seconds, I've got eight injectors blasting gas during those 2 seconds. I know, I know... flammable stuff. I have put towels under them to minimize splatter and have my fire extinguisher in my hand. Scary stuff but here is what I found.

-With wires connected, injectors shoot fuel when fuel pump runs.
-With key still in run, injectors shut off when fuel pump stops.
-With wires off injectors, no leakage at all. Fuel pressure stays 45 lbs.

All injectors have 12 volts but where are they picking up the ground to shoot off continuous fuel and why??
Any help appreciated...

 

this could be a few things. The grounds are wired together in series so a bad harness point is grounding the harness. the injectors always have 12 volts and they are batch fired.. all 8 at once on a tpi.. or the ecu driver is shorted,
remove the ground wire from the harness connector and turn on the key. if the injectors still squirt then the harness is grounded somewhere. if they don't squirt then look at the ecu

 

All eight fire at the same time?? I'd have lost money on that bet. So, I'm looking to remove the ground on the harness. By the way, I have a "painless wiring" engine harness. Hope that doesn't matter. Going outside to look.

 

lol "painless"

I would have lost money too

 

OK... I have not found the harness ground. Thought removing the ECU would tell me if the ground was at fault. Well, fuel pump won't run without ECU. I got my wiring harness manual out and will study some more. Will check back as soon as I smoke test again.

Any more thoughts would be greatly appreciated.

 

JUMP THE FUEL PUMP RELAY AND GET THE FUEL GOING.. IF IT STILL LEAKS INTO THE ENGINE I WOULD PUNT. COULD ALL 8 BE LEAKING? NAA! HAS TO BE ELEC CIRCUIT.

 

I may have something. After looking at the manual, I realized a grounded injector wire could be checked since the ECU end of the harness was loose. Back when everything was hooked up the Pink wires had 12 volts on them all the time. Now with ECU disconnected, I find no continuity between the blue injector wires and ground so I am concluding that my harness is okay... Right??
----------
If it is the ECU, would it be the electronics or the chip??

 

thats a good question.. there is a small transister in the injector driver circuit that is basically a switch,, that could be bad. i don't think the chip would cause the driver to stay closed. it is normally open, the chip tells the driver when to close and ground the injectors. I still bet its in your harness, keep looking or borrow an ecu. the two wires of the harness would not have continuity.. check the ground wire from the injectors to chassis ground, not the 12vlt.. if they were touching they would blow the injector fuse

 

Confirmed last nite there is no continuty between injector ground wires and the chassis ground. I tore the ECU apart looking for a popped transistor on the board but did not see or smell anything wrong.

I agree about the grounding of my harness. All eight shooting a steady stream just ain't right. With my ECU out, maybe that disconnected the injectors that I checked. I will check ALL eight injector grounds first. Then re-install the ECU and check them again.

I would be sick if I bought a new prom or a burn kit, put it all in and still have this problem.

Update tonite... In the meantime, if any ideas or suggestions popup, bring'em on. I need them.

 

Help if you can. I need it!! Here is what I found with key switch off...

With the ECM disconnected:
Injector ground wires do not have continuity to chassis ground.
All right side injectors grounds are connected to each other.
All left side injectors grounds are connected to each other.
Right and Left injector wires are not connected to each other.

With ECM connected:
All injector ground wires have continuity to chassis ground - (1.55 kOhm)
Right and Left injector wires are all connected to each other.

If I turn the key to run position, all eight injectors spray gas like a car wash for 2 seconds!!

Looking at what I found... is my injector switch shorted to ground??

If so, where do I get a new one??

If not, what could it be?



.

 

Done Deal... Key to run and no more injectors spraying like the car wash.

Here's what I found:
With all the injector wires off and measuring the injector ground wire to chassis ground, the electronics 1227165 had a resistance of 1.5kOhms. (1500)

My new off-brand rooty-poot hurry up and get-r-done replacement that looks like it got drug behind the car before it was reworked had a resistance of 88kOhms.(88000)

A big difference in resistance to chassis ground AND enough that my injectors do right now. Going to put everything back together and cross my fingers that it will run. I never found what blew the injector circuit so it may very well happen again.

Thanks for the pointers!!