Runs fine, then Sputters and dies. Please help
04-21-2013, 08:00 AM
#1
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Year: 99
Model: Cherokee
Engine: 4.0L
Runs fine, then Sputters and dies. Please help
So I'm having an issue with my 99.
No engine mods. 99 with 201,000 KM on it. 4.0L.
She runs fine until it gets up to operating temp, and then she kicks sputters and dies (mostly going up hill). It'll fire up right away but dies shortly afterwards. If I let it sit for a while it'll start and drive fine for about 5-10 mins then dies out again. At idle, it's good but when I start driving it'll die.
Volts are at a constant 13.5-14
Oil pressure at the 3 on the gauge
Temp is dead smack in the middle where it should be
Fuel pump was changed less than 3 month ago
Oil was changed 2 days ago
No abnormal smoke coming from exhaust, but it does smell like rotten egg when it's acting up and running rough.
I was thinking bad gas, until I went to the last station of fill up and try said I was the first to report any issues.
Any ideas?
No engine mods. 99 with 201,000 KM on it. 4.0L.
She runs fine until it gets up to operating temp, and then she kicks sputters and dies (mostly going up hill). It'll fire up right away but dies shortly afterwards. If I let it sit for a while it'll start and drive fine for about 5-10 mins then dies out again. At idle, it's good but when I start driving it'll die.
Volts are at a constant 13.5-14
Oil pressure at the 3 on the gauge
Temp is dead smack in the middle where it should be
Fuel pump was changed less than 3 month ago
Oil was changed 2 days ago
No abnormal smoke coming from exhaust, but it does smell like rotten egg when it's acting up and running rough.
I was thinking bad gas, until I went to the last station of fill up and try said I was the first to report any issues.
Any ideas?
04-21-2013, 08:10 AM
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Year: 1999
Model: Cherokee
Engine: 4.0
1. Ever see a check engine light? If so, you must pull codes for clues.
2. First thing I would do is to verify fuel pressure. I know you have a new fuel pump installed, but new parts fail way more often than you think. What brand fuel pump did you install? For a 99, you should have 49 psi, plus or minus 5 psi. Must be tested with a gauge which can be rented inexpensively from many parts stores.
3. The #1 and #2 cause of thermal (heat related) failure are the crankshaft position sensor and the ignition coil. In that order.
2. First thing I would do is to verify fuel pressure. I know you have a new fuel pump installed, but new parts fail way more often than you think. What brand fuel pump did you install? For a 99, you should have 49 psi, plus or minus 5 psi. Must be tested with a gauge which can be rented inexpensively from many parts stores.
3. The #1 and #2 cause of thermal (heat related) failure are the crankshaft position sensor and the ignition coil. In that order.
04-21-2013, 08:21 AM
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Year: 99
Model: Cherokee
Engine: 4.0L
1. Ever see a check engine light? If so, you must pull codes for clues.
2. First thing I would do is to verify fuel pressure. I know you have a new fuel pump installed, but new parts fail way more often than you think. What brand fuel pump did you install? For a 99, you should have 49 psi, plus or minus 5 psi. Must be tested with a gauge which can be rented inexpensively from many parts stores.
3. The #1 and #2 cause of thermal (heat related) failure are the crankshaft position sensor and the ignition coil. In that order.
2. First thing I would do is to verify fuel pressure. I know you have a new fuel pump installed, but new parts fail way more often than you think. What brand fuel pump did you install? For a 99, you should have 49 psi, plus or minus 5 psi. Must be tested with a gauge which can be rented inexpensively from many parts stores.
3. The #1 and #2 cause of thermal (heat related) failure are the crankshaft position sensor and the ignition coil. In that order.
No CEL. I'll see if I can find a gauge to test the PSI, BUT like I said, it starts and runs find when it's cold. it's only when it warms up that it acts up.
that being said, how can I test the CPS on a post renix?
04-21-2013, 08:57 AM
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Year: 99
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04-21-2013, 09:08 AM
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Year: 89
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Before you throw a CPS at it. Next time it's warm & won't start stick your water hose down there & run some cold water over the sensor & see what happens. It's a cheap test. Do a multimeter test on it also.
You also need to check fuel pressure & do a leak down test which will tell if it's check valve or goofy injectors or goofy FP regulator.
I've had "years" of experience with HNS. (hot no start)
You also need to check fuel pressure & do a leak down test which will tell if it's check valve or goofy injectors or goofy FP regulator.
I've had "years" of experience with HNS. (hot no start)
04-21-2013, 09:18 AM
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Year: 99
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Engine: 4.0L
Before you throw a CPS at it. Next time it's warm & won't start stick your water hose down there & run some cold water over the sensor & see what happens. It's a cheap test. Do a multimeter test on it also.
You also need to check fuel pressure & do a leak down test which will tell if it's check valve or goofy injectors or goofy FP regulator.
I've had "years" of experience with HNS. (hot no start)
You also need to check fuel pressure & do a leak down test which will tell if it's check valve or goofy injectors or goofy FP regulator.
I've had "years" of experience with HNS. (hot no start)
04-21-2013, 09:33 AM
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Year: 89
Model: Cherokee
Engine: 4.0
HNS can & will include starting but running like crap. Mine would start many times & idle ruff as heck then clear up, idle fine, then sputter out.
Here's another simple & easy way to eliminate some things it could or could not be (per your rotten egg smell possible clogged exhaust)
http://www.secondchancegarage.com/public/186.cfm
Vacuum testers are pretty in expensive & will tell you a lot about running & engine condition.
Here's another simple & easy way to eliminate some things it could or could not be (per your rotten egg smell possible clogged exhaust)
http://www.secondchancegarage.com/public/186.cfm
Vacuum testers are pretty in expensive & will tell you a lot about running & engine condition.
04-21-2013, 01:34 PM
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Year: 99
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Changed out the CPS...No Buenos. Still having the stumbling and stalling issue BUT only when going up hills
04-21-2013, 04:31 PM
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Still at a loss here... no way to drain my tank in the driveway. If I don't figure it out tonight, it going to the shop in the morning
04-21-2013, 06:22 PM
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Year: 99
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SOOO... I may have solved the problem... KNOCK ON WOOD.
My mechanic buddy had a theory; A simple one at that. I have to admit, it crossed my mind multiple times, but I never really gave it much thought. WATER IN THE TANK.
His theory was this..."Water is heavier than gas, right? WELL if its heavier, then it stands to reason that it will separate somewhat and sink to the bottom of the tank and on inclines or certain angles, it can slosh around and be moved around closer to the pick up inside the tank, causing it to be sucked up only at certain times. Such as when the vehicle is angled in a certain way."
This actually makes sence, SO I grabbed some STP Water Remover from the shell gas station, dumped it in the tank and filled it up with 89 as opposed to 87 (to help dilute and other remaining water in the existing fuel). I just got back from a 30-40 minute drive all around the countryside. Up and down hills, into ditches sideways and whatnot to cover as many angles as I possibly could. LOW AND BEHOLD, not a single stutter.
Lets hope that solves the mystery. Time will only tell....Thanks for all the suggestions!
My mechanic buddy had a theory; A simple one at that. I have to admit, it crossed my mind multiple times, but I never really gave it much thought. WATER IN THE TANK.
His theory was this..."Water is heavier than gas, right? WELL if its heavier, then it stands to reason that it will separate somewhat and sink to the bottom of the tank and on inclines or certain angles, it can slosh around and be moved around closer to the pick up inside the tank, causing it to be sucked up only at certain times. Such as when the vehicle is angled in a certain way."
This actually makes sence, SO I grabbed some STP Water Remover from the shell gas station, dumped it in the tank and filled it up with 89 as opposed to 87 (to help dilute and other remaining water in the existing fuel). I just got back from a 30-40 minute drive all around the countryside. Up and down hills, into ditches sideways and whatnot to cover as many angles as I possibly could. LOW AND BEHOLD, not a single stutter.
Lets hope that solves the mystery. Time will only tell....Thanks for all the suggestions!
04-21-2013, 06:54 PM
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Year: 99
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That was part of my drive. LOL I found a backroad with about a 30-35 degree incline and parked for a bit to see. nothing. Reved it up and held it around 2000-2200 RPM and nothing...