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Leaky injector or injectors ??

WheelinJR

NAXJA Forum User
Location
Portland, Oregon
This is a 91 Laredo 4x4 Auto, High Output 4.0, 176K miles

So the first time i went and played in the Jeep my clamped on muffler fell off.

Since then I've noticed considerable gas mileage loss (I'm averaging maybe 12mpg?) and I figured getting a muffler back on would take care of it, which I plan to do this week.

Then the other day something weird happened. I pulled into a drive-thru and shut it off cause I couldn't hear the speaker. When I tried to restart, it wouldnt fire. I ended up having to hold the throttle wide open to get it to start, and it reaked of raw fuel when i was cranking it

Its the first and only time that has ever ever happened. Its been fine ever since and runs like a top. not one flaw.

possible leaking injectors?
 
You need to start it up and actually LOOK at the injectors to see if they are leaking...Since the JEEP engineers decided to put the EXHAUST manifold directly under the INJECTORS..this is not something you wanna guess at.
Another possibility is the fuel pressure regulator I had one go on mine along with injector o rings..
O rings,on the FPR...O rings on the injectors x2 can be the cause of a fuel leak....as can a bad injector or a bad FPR.
O rings should all be replaced at the same time
injectors should all be replaced at the same time
FPR should be replaced completely IMOHO
IF YOU DO REPLACE THE INJECTORS..LABEL THE WIRING HARNESS TO EACH INJECTOR
ALSO DISCO THE BATTERY JUST TO BE SAFE
 
i don't mean an actual leak to where fuel is escaping the system. i mean a leak to where when injectors are supposed to be closed but they arent closing.

externally the fuel system is not leaking out at all.
 
Possibly a fuel injector leaking into the intake, but much more likely that a faulty sensor produced a no-spark condition. Intermittent electrical loss-of-spark is most often a failing CPS (crankshaft position senor, at 11 o-clock on the bell housing). If you get random quitting (especially giving it gas from idle), then try unplug/replug the CPS as a temporary fix.
 
4xBob said:
Possibly a fuel injector leaking into the intake, but much more likely that a faulty sensor produced a no-spark condition. Intermittent electrical loss-of-spark is most often a failing CPS (crankshaft position senor, at 11 o-clock on the bell housing). If you get random quitting (especially giving it gas from idle), then try unplug/replug the CPS as a temporary fix.

its never died, just that one no start, and holding the throttle open started it.

I have noticed a new symptom where it doesn't like to idle down, I can let off the gas at 35mph sometimes and it will maintain that speed. It's also been idling at 1000rpm when it used to idle more around 750ish.

the not starting issue I have not been able to reproduce, its always started right up before that and ever since too....weird.
 
I think its safe to toss out the injector idea.
I think its low coolant causing the IACV to bug out.
Today I noticed that while rolling if I put it in neutral it would spin up to 2000rpm, and it would idle at 1000rpm. And I had two more hard starts.
Then when I got to the bank today I noticed my front diff was soaked.
I can't find the leak, the highest wet spot appears to be just above oil pan on the front of the block on the left side. When I refilled the coolant and drove a lil while the weirdness went away, hard start went away, idle normalled out, and things acted right.
Now to find the leak, waterpump.
 
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