hesitation issue
#1
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Year: 1987
Model: Cherokee
Engine: 4.0 str8 6
hesitation issue
new to forums and hoping to get some help. searched through the forums and didnt really find anything that fit my issue so im hoping someone can lend some help. just bought an 87 jeep cherokee and changed fuel filter, plugs, wires, valve cover gasket and cap and rotor. starts up fine and seems to idle pretty good but in hitting the gas it hesitates before reving up. i see there can be many things that can cause this but has anyone had this happen and know how to fix it??? i checked coil and and it seems to have tested good. so im not sure where to start next being that i have never owned a jeep before. thanks in advance :-)
#3
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Year: 1987
Model: Cherokee
Engine: 4.0 str8 6
not sure exactly what it was doing before...it was my cousins jeep and he said he had stalled on him before. it was sitting at his house for awhile and all he did was start it up on occasion. i got it from him and drove it home it ran pretty rough and blew out a lot of carbon build up when i gunned it onto the freeway. so i gave it a tune up as mentioned and it ran a whole lot better its just the hesitation when hitting the gas to rev it. the idle seems pretty good and doesnt seem to have a miss to it
#4
Caracticus Potts The Mod
Two thing s come to mind right off.
Check the fuel pressure.
2nd) unplug the O2 sensor, that will cause the ecm to default to .5 volt(also known as center) if the hesitation is gone then replace the O2 sensor if it remains check the fuel pressure regulator for proper vacuum and repair or replace it if needed
Check the fuel pressure.
2nd) unplug the O2 sensor, that will cause the ecm to default to .5 volt(also known as center) if the hesitation is gone then replace the O2 sensor if it remains check the fuel pressure regulator for proper vacuum and repair or replace it if needed
#6
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Year: 1987
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Engine: 4.0 str8 6
ok i will check that out thanks!! also is it normal to hear what sounds like gas going from engine back to gas tank when standing in front of jeep after you shut it off???
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#8
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Year: 1987
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truthfully i have no idea what it is...just sounds like water going back into something so i figured it was gas going back to tank or something
#10
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Year: 1987
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should i also be getting vacuum from both hoses coming from the valve cover ?????
Last edited by secondzaway; 04-30-2010 at 12:08 AM.
#11
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Year: 1989
Model: Cherokee
Engine: 4.0L
The water going back into something you hear is likely coolant draining back into the radiator. It's somewhat normal but you may be a bit low on coolant. All 3 of of the XJ's I've had have done that even when pretty much full, but check the coolant levels.
The 89 I've got and am working out the kinks on now is doing the same hesitation thing. The 87 I had did the same thing but not as bad. It's likely one or more of a few things, IAC, TPS, CPS, dirty throttle body, possibly 02 sensor related. I've got a new IAC, new exhaust (but you didn't mention exhaust noise) and new EGR solenoid and mines running way better than when I got it but still has the hesitation issue. I'm going after TPS and throttle body cleaning next.
Post your results and I'll post mine, seems this is common with the Renix models and I'm going down the list of fixes I've found searching here as I have time and money but haven't seen many say which of these actually fixed their issue Mostly people like us trying to figure ours out.
Cheers and welcome!
The 89 I've got and am working out the kinks on now is doing the same hesitation thing. The 87 I had did the same thing but not as bad. It's likely one or more of a few things, IAC, TPS, CPS, dirty throttle body, possibly 02 sensor related. I've got a new IAC, new exhaust (but you didn't mention exhaust noise) and new EGR solenoid and mines running way better than when I got it but still has the hesitation issue. I'm going after TPS and throttle body cleaning next.
Post your results and I'll post mine, seems this is common with the Renix models and I'm going down the list of fixes I've found searching here as I have time and money but haven't seen many say which of these actually fixed their issue Mostly people like us trying to figure ours out.
Cheers and welcome!
#12
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Year: 1995
Model: Cherokee
Engine: 4.0 liter
are you leaking oil? because i hear a slurping sound. or "water" moving back an forth. but my rear main is leaking. so it could be your oil.
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Year: 1991
Model: Cherokee
Engine: 4.0L H.O.
The water going back into something you hear is likely coolant draining back into the radiator. It's somewhat normal but you may be a bit low on coolant. All 3 of of the XJ's I've had have done that even when pretty much full, but check the coolant levels.
The 89 I've got and am working out the kinks on now is doing the same hesitation thing. The 87 I had did the same thing but not as bad. It's likely one or more of a few things, IAC, TPS, CPS, dirty throttle body, possibly 02 sensor related. I've got a new IAC, new exhaust (but you didn't mention exhaust noise) and new EGR solenoid and mines running way better than when I got it but still has the hesitation issue. I'm going after TPS and throttle body cleaning next.
Post your results and I'll post mine, seems this is common with the Renix models and I'm going down the list of fixes I've found searching here as I have time and money but haven't seen many say which of these actually fixed their issue Mostly people like us trying to figure ours out.
Cheers and welcome!
The 89 I've got and am working out the kinks on now is doing the same hesitation thing. The 87 I had did the same thing but not as bad. It's likely one or more of a few things, IAC, TPS, CPS, dirty throttle body, possibly 02 sensor related. I've got a new IAC, new exhaust (but you didn't mention exhaust noise) and new EGR solenoid and mines running way better than when I got it but still has the hesitation issue. I'm going after TPS and throttle body cleaning next.
Post your results and I'll post mine, seems this is common with the Renix models and I'm going down the list of fixes I've found searching here as I have time and money but haven't seen many say which of these actually fixed their issue Mostly people like us trying to figure ours out.
Cheers and welcome!
Oh P.s. i forgot i had hesitation in my 91 Changed the FUEL FILTER and solved a ton o the problem. took it out and couldn't even blow through it.
#14
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Year: 1987
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already changed out the fuel filter and i do think its low on coolant from removing hoses out of my way changing plugs and valve cover gasket...thanks again for all the suggestions everyone...ill start looking into it more this weekend
#15
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Year: 1987
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ok just got the jeep registered so now ill be driving it...but to let everyone know...i talked to a buddy of mine and he said hes pretty sure its hesitating due to carbon build up. i floored it on freeway and a huge carbon cloud shot out the exhaust. so i bought some good fuel cleaner to clean it all up and hopefully it will cure the hesitation. thanks for everyones help and ill keep you posted!!