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Intermittent hard starting problem... I have searched

RedJeep2.0

NAXJA Forum User
NAXJA Member
Location
Vancouver, WA
Ok, well I have had this problem for a while.

Only does it some times, well I am done and I want to fix it!

I have an 88 auto 4.0 230,000 miles

it runs gr8 when it starts.
When starting it cranks good like every other jeep, at about the time every other jeep would start mine will bog down try to start Then cranks good for 1 - 2 sec then bog down Then crack good ... So on till I get lucky and it starts, some time the frist time some times 3 to 5 mins trying to start.

Every time I try something to fix it, it won't do it for a while after... But it just might be me.

Ok the new...
Red top ( cuz when cranking it bogs like it's a dead battery)
new starter
new MAP
new idel air
new power wires to starter ( 2ga)
new grounds strate to starter ( 2ga)
new ground from block ( 2ga)
new cap/ rotor and all tune up stuff
new fuel filter
new fuel pump
new CPS ( swaped it out 3times)


Any body got anything I should try?

Keep in mind it does this hot or cold.

Or is there something I could check?
I have been thinking about a new distributor or maybe it's off a tooth? I have a timing gun is there a way to check?
 
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try priming the fuel pump by cycling the key on off on off start and see if the fuel pump check valve is not keeping fuel where it's supposed to be
 
try priming the fuel pump by cycling the key on off on off start and see if the fuel pump check valve is not keeping fuel where it's supposed to be

when i do this, the fuel pump runs (the frist time i turn the key) then off then back on a few times, the pump does run.
for a sort time on the 3rd turn on of ther key...
im i looking to see if the pump primes every time?
 
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Did you go from the battery all the way to the starter? This way checks your solenoid too. Post your total numbers for us.
 
The 4.0 distributor has ZERO to do with ignition timing. You could remove the distributor and not effect timing--period.

The CPS/CKP crank sensor generates signals to the ECU/PCM and it uses that information to vary the timing of the engine. You can check your timing with a light, you can't change it (without modifying the CPS/CKP sensor).

The Renix must "spin up" to 300 RPMs BEFORE the CPS/CKP will generate enough of a signal for the ECU/PCM to determine it is time to "fire" the coil.

If you are cranking for more than about 15 seconds at a time you are probably damaging the starter/solenoid by overheating it--leading to problems like you are describing.

You say "new" starter--as in NEW or "new" to you--reman? With the battery and 2 ga cables you should be getting quite a fast cranking of the engine--is it? If you jump the wires on the starter does it crank better than when using the key?

Ran a compression test lately--if so, what are the numbers?

Have you run a fuel system pressure test? Yes, I know you put on a new pump, but that doesn't tell me the condition of the pressure regulator.

What is the condition of the fuel injectors?
 
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