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Does any one have any insight?? To the following.

XJ91

NAXJA Forum User
Location
G'Nagiwanka
"Most common cause of long start times or engine not kicking over is CPS."


I hate my heep when starting it. Takes a good 5-7 seconds, must crank a good 10 times. Drives me MAD

I have replaced my wires, cap, roter, plugs, Removed and cleaned throtle body, removed and cleaned Valve Cover
 
try to put some zip ties on the CPS harness and try to get it as tight as you possibly can maybe. that is assuming your CPS is good to begin with
 
May also be fuel pressure bleeding off after you shut it off. When you turn the key on without starting the engine you should hear the fuel pump in the rear filling the lines and then stop. Then, without turning the key off, start it and see if it starts faster.
 
DPC said:
May also be fuel pressure bleeding off after you shut it off. When you turn the key on without starting the engine you should hear the fuel pump in the rear filling the lines and then stop. Then, without turning the key off, start it and see if it starts faster.

I think my pressure was bleeding off as well when it was turned off. Usually took 2-4 attempts to get it running, but it would start right up if it hadn't been off for a long while. My solution was to cycle the fuel pump twice before trying to start. In other words, turn the key forward til the radio comes on, then off again then turn it forward, then crank it. Starts first time, everytime now. Just my .02.....
 
Here's the crappy pic that the shop manual has of the CPS's wire harness. The arrow points towards the front of the engine. The wires plug into the main harness at the very back of the valve cover on the driver-side. It's there somewhere, just keep looking for a plug whose wires run back to the tranny. The manual says that the sensor should be tested with a hot engine (not running!) and should read between 150 and 300 ohms.
Jeep on!
--Pete
30764912.jpg
 
ThanX for the help...

I guess, I'll price out a fuel pump.

DPC
May also be fuel pressure bleeding off after you shut it off. When you turn the key on without starting the engine you should hear the fuel pump in the rear filling the lines and then stop. Then, without turning the key off, start it and see if it starts faster.

It still does the same thing even after turning the key to ON, then crank...:banghead:
 
Pete M said:
The manual says that the sensor should be tested with a hot engine (not running!) and should read between 150 and 300 ohms.
Jeep on!
--Pete
30764912.jpg

For a 91 up, the sensor should read as an "open circuit" (infinite resistance) with an ohmmeter on the 1K to 10k scale. If you get numbers, it's bad.
 
Is infinite resistance for a cold engine? This is the page from my 91 shop manual:

30816475.jpg


The other resistance numbers were ones I grabbed mistakenly from my 89 manual. A '91+ CPS should be 125-275 ohms on a hot engine.
Jeep on!
--Pete
 
My mistake on years, it seems. Adding confusion to the issue, the 95 FSM does not say hot or cold, but says "Place an ohmmeter across terminals B and C. The ohmmeter should be set to 1K-to-10K scale for this test. The meter reading should be open (no resistance). REplace sensor if a low resistance is indicated."

I know that the 93 also reads open when good, and had assumed that this was common to post-Renix systems, but I see from the Haynes manual that 91 and 92 use different terminals, though Haynes also says it should read open. Of course Haynes is often wrong, so it's obvious I don't really know the specs for 91 and 92!
 
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