TPS or computer fried? - no start
#16
Newbie
Thread Starter
So, still dicking around with it. Just finished doing a C101 deletion, rechecked my grounds and vacuum lines. No start. What would keep my injectors from spraying? other than the computer? I have spark and fuel.
#17
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Fuel pressure correct?
Test for power at injectors when cranking. The colored wire is the voltage to the injectors and where you should check.
Test for power at injectors when cranking. The colored wire is the voltage to the injectors and where you should check.
#18
I would double/triple check your spark and fuel pressure, possible bad crank position sensor / loose connection / misaligned or dirty sensor.
And if you haven't read it The Renix Bible: Gospel of Cruiser54 has never lead me astray and alway got my jeep back on the road.
And if you haven't read it The Renix Bible: Gospel of Cruiser54 has never lead me astray and alway got my jeep back on the road.
#19
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Year: 1989
Model: Comanche (MJ)
Engine: 4.0
If he's got spark, probably not a crank sensor issue. I'd verify fuel pressure and that you hear the fuel pump run when you first turn the key on. Did you maybe whack the fuel pump ballast resistor on the drivers fender (assuming you have one, an 88 might not)? That usually causes a stall after the initial start though. That's a great spot to check for voltage and amperage to the fuel pump, btw. As Cruiser mentioned, use a noid light or a meter to check for +12-volts pulsing to the injectors while cranking. On the Renix they all share a common ground, and the computer controls the positive side of the injector.
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Kuro89 (02-11-2022)
#20
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Thread Starter
The fuel pump turns on, the ballast resistor was deleted by the previous owner. and i did notice, when i was messing around with the injector voltage' and having to twist some of the injectors in the process, i noticed fuel leaking from the #6 injector when giving it a twist.. I recently pulled some 746 injectors from a junkyard, So, i went ahead with the fuel injector swap. When pulling the injectors off of the rail, they came off super easy no resistance. Cleaned up the rail and with the 746 injectors put everything back together..and after a couple cranks, the engine came to life, tho a little rough.. will need to go back and adjust the TPS.
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Kuro89 (02-13-2022)
#21
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Year: 1990
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Nice job!!
#22
Newbie
Thread Starter
So, after all of the changes, esp the "new" injectors... I'm getting quite a bit of smoke(white) out of the exhaust. Is that normal when messing with injectors? Gumk that fell down into the cylinder?
Last edited by jekel77; 02-13-2022 at 02:48 PM.
#23
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Year: 1990
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Not really. Did it quit smoking?
#26
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Year: 1990
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Make sure the tang on the TPS is moving with the throttle linkage.
#27
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Thread Starter
I"m fairly sure it is, i'll double check in the morning. So, it seems to be inconsistent. I unplugged the O2 to see if it ran better, it seemed to. Then, I took it up to the gas station, which is less than a mile away...on the way back, the engine was stumbling under normal acceleration and idle. I"m thinking maybe my grounds aren't 100%, so gonna redo the sensor grounds tomorrow and also replace the TPS connector with a new one(those pins seem too easy to move).
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