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Discussion Starter · #1 · (Edited)
Background: I have a 1968 Jeep M715; engine is a 1996 LT1, with a 1995 computer so it's OBD1. I use a computer to see all diagnostics.
Situation: My son moved it out of the garage over Thanksgiving. When I went to move it back, it started and in reverse moved a foot then died. I started it again, it ran one second, and died. Now it won't start.
Diagnostics: It's not showing any error codes. Battery is fine and turning the starter, which is turning the engine so I assume it's not those. When we spray starter spray into the air intake it starts and runs for a couple of seconds; I guess this means plugs, wires, and optispark are working. Fuel pump is making noises and when we push the pressure test schrader valve it squirts fuel out.
What are my next steps?
Tire Plant Wheel Automotive parking light Vehicle
 

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Discussion Starter · #2 ·
Update: Today I checked the the pulse to the fuel injectors using a noid light. I also checked the voltage going to each. I also used the old listen to the screwdriver on the fuel injector test, and heard the ticking on all eight. I went back to test fuel pressure, it's 49psi.
I have spark, I have fuel pressure, I have signal to fuel injectors, I have ticking of fuel injectors opening and closing. What else is there?

Next step: Take of fuel rails and injectors to look for blockages in everything.
 

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Does it still fire up on starter fluid? Where did you test the fuel pressure? If it fires on starter fluid, you have spark and it's at the correct time. If you have pressure on the fuel rail, and can hear the injectors clicking, you should get some indication it's firing at least sometimes.

Al in Tucson
 

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Discussion Starter · #6 ·
I haven't tried the spray again because the fuel rail is sitting out right now. I tested each injector individually and they each click. However, I only had enough spray cleaner to test one and see it actually spray. I have another can and just need time to do it. The fuel rail has no clogs in it.
 

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Oh wow. I just looked it up. This Jeep doesn't even HAVE a key. It just has a push button. How could I reset or turn off this feature on the computer?
However, the noid light shows it is still sending a pulse to each injector. How does the security system stop fuel going through the injectors? I assume it would stop the pulse, unless there is a mechanical way to stop the flow of fuel.
 

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Oh wow. I just looked it up. This Jeep doesn't even HAVE a key. It just has a push button. How could I reset or turn off this feature on the computer?
However, the noid light shows it is still sending a pulse to each injector. How does the security system stop fuel going through the injectors? I assume it would stop the pulse, unless there is a mechanical way to stop the flow of fuel.
Don't start chasing your tail. If you have fuel and spark, it should start. Do you know about TunerCat

Al in Tucson
 

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Discussion Starter · #10 ·
I used some spray Sea Foam and a fuel injector tester to watch the spray pattern. Odd. When using the tester, the injectors would click click click. But when attached to the pressure coming from the can, the click would stop. Then one of them just spouted out sea foam constantly like it was stuck open. I'm soaking the injectors in sea foam over night to see if they will function after a deep clean.
 

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Tunercat
I have a different program to hook my laptop up, but it's not showing any errors that I can tell.
Can you shut off the VATS with your program? If it was the VATS, and the starter is hooked up the way it was in the car, the starter will not operate. And you'll have no pulses to the injectors.

If the starter is wired directly to a switch or button, it will crank but not have injector pulses.

Did this vehicle ever run correctly?

Al in Tucson
 

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Discussion Starter · #15 ·
Tableware Solution Ingredient Liquid Juice

Tableware Liquid Drinkware Water Window

It's Alive!!!!
After looking at every component and replacing a faulty fuel pressure regulator, and cleaning and testing every fuel injector, someone suggested testing the gas. I unplugged the fuel line from the rail and dropped it into a five gallon bucket. The first two gallons were clear like water (the left jar in the photo). Then it started pouring out a milky white liquid for 2 or 3 gallons (middle jar). Then finally, it poured out the yellowish fuel (right hand jar). Once I saw that, I tried starting it again and it roared to life.
A few days later I looked at the jars again and the milky jar had separated into clear on the bottom and yellow on top. I think it must be water. Three possibilities: rain water seeped in, vandalism, or water in the gas station tanks.
 
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