Turns over many times before starting
03-29-2017, 11:59 AM
#2
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Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
What year? Also...try turning the ign on a few secs, off, then on again a few secs, a few times. The pump runs just two seconds with ign on. Doing this pressurizes the rail and will help it start if it's loosing pressure via the check valve in the pump or the injectors. (called "the poor man's prime)
Last edited by DFlintstone; 03-29-2017 at 12:10 PM.
03-29-2017, 01:50 PM
#3
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Year: 1987
Model: Cherokee (XJ)
Mine did the same thing before I replaced the fuel pump. If I primed it 5 times or so, it would fire right up. New fuel pump fires up first time every time.
03-29-2017, 06:28 PM
#4
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I dont mind replacing the fuel pump, I just want to be sure its the right direction to go. I'm not a mechanic so I dont have a deep understanding of the fuel system.
03-29-2017, 07:38 PM
#5
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Year: 1998 Classic (I'll get it running soon....) and 02 Grand
Model: Cherokee (XJ)
Engine: 4.0
Do a fuel pressure test first. What year is your beast?
If it is the pump, don't buy just any old brand. The Bosch and the Carter are recommended. Airtex, NOT.
If it is the pump, don't buy just any old brand. The Bosch and the Carter are recommended. Airtex, NOT.
03-30-2017, 11:26 AM
#7
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03-30-2017, 12:03 PM
#8
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Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
92...is your regulator on the front of the fuel rail with a vacuum line to it? If so pressure is 39# with the vacuum line off and 29# with it on. Am I backwards there?
There are specs for how the pressure bleeds down that I don't remember. Guess you could check it first then go from there. If it plummets, weather it's a pound a minute or 10 lbs in 20 minutes or whatever won't matter. If it stumbles and misses for a few seconds after starting, that's a sign of injector leak. The fuel pressure regulator can also leak, much more rare I think.
Did doing the poor mans prime help or not?
Yea, for years we could put our year right there with our avatar. Now there are lot's more clicks happening because we need to ask and guess and fumble around in the dark. I bet the CL, and the advertisers are sick over it.
There are specs for how the pressure bleeds down that I don't remember. Guess you could check it first then go from there. If it plummets, weather it's a pound a minute or 10 lbs in 20 minutes or whatever won't matter. If it stumbles and misses for a few seconds after starting, that's a sign of injector leak. The fuel pressure regulator can also leak, much more rare I think.
Did doing the poor mans prime help or not?
Yea, for years we could put our year right there with our avatar. Now there are lot's more clicks happening because we need to ask and guess and fumble around in the dark. I bet the CL, and the advertisers are sick over it.
03-30-2017, 05:15 PM
#10
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Year: 1987
Model: Cherokee
Engine: 4.0
Mine was same way for 4 yrs. I not to long ago gave it full tune up going with a brass connection distributor cap(as suggested) new rotor and champion plugs along with i do run an accel super coil and 8mm super stock wires. The beast starts up better than it has since owned....
03-30-2017, 05:32 PM
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Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Being it's free you might want to verify pressure, (and bleed-down) with a gauge. I(f the poor man's prime didn't help pressure might not be the problem. Slim has a good point. Those aluminum electrode dizy caps are trash. That is something you can check-change anyway, even if it's not your issue.
Not sure if the parts store can read your OBDI, maybe though. (it's free). Yours has an on-board code reader>
The "Key trick"
OBD1 Models: 1991-1995
1) Start engine (if possible). Move transmission shift lever
through all positions, ending in Park. Turn A/C switch on and then off
(if equipped).
2) Turn engine off. Without starting engine again, turn
ignition on, off, on, off and on within 5 seconds. Record 2-digit
fault codes as displayed by flashing MIL.
3) For example, fault code 23 is displayed as flash, flash,
4-second pause, flash, flash, flash. After a slightly longer pause,
other codes stored are displayed in numerical order. When MIL begins
to flash fault codes, it cannot be stopped. Start over if count is
lost. Code 55 indicates end of fault code display.
Not sure if the parts store can read your OBDI, maybe though. (it's free). Yours has an on-board code reader>
The "Key trick"
OBD1 Models: 1991-1995
1) Start engine (if possible). Move transmission shift lever
through all positions, ending in Park. Turn A/C switch on and then off
(if equipped).
2) Turn engine off. Without starting engine again, turn
ignition on, off, on, off and on within 5 seconds. Record 2-digit
fault codes as displayed by flashing MIL.
3) For example, fault code 23 is displayed as flash, flash,
4-second pause, flash, flash, flash. After a slightly longer pause,
other codes stored are displayed in numerical order. When MIL begins
to flash fault codes, it cannot be stopped. Start over if count is
lost. Code 55 indicates end of fault code display.
Last edited by DFlintstone; 03-30-2017 at 05:38 PM.
03-30-2017, 06:02 PM
#12
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Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Easy enough to check on this little booger and rule that out>
There is a brittle little tube. It comes out of a rubber plug, low on the engine side of the throttle body. It runs back to the firewall, then up to your MAP sensor sort of high up there near center on the firewall. CRUCIAL!! The MAP will tell the ECU to dump fuel with less/no vacuum. Any crack or blockage and it will be pig-rich. (maybe black smoke, fouled black plugs). You can pull the line off the MAP and feel for vacuum with your finger. If it runs!
There is a brittle little tube. It comes out of a rubber plug, low on the engine side of the throttle body. It runs back to the firewall, then up to your MAP sensor sort of high up there near center on the firewall. CRUCIAL!! The MAP will tell the ECU to dump fuel with less/no vacuum. Any crack or blockage and it will be pig-rich. (maybe black smoke, fouled black plugs). You can pull the line off the MAP and feel for vacuum with your finger. If it runs!
03-31-2017, 06:26 AM
#13
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I recently replaced plugs and wires and cap. I dont recall if it was aluminum tipped or not so ill check that. Will the auto parts store check fuel pressure for me for free?
They might rent the gauge setup for free, though.
03-31-2017, 09:22 AM
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0