S.O.S JEEP HAS SPUTTERING ISSUES

Ok well i have been searching through different sites google jeep forumes etc.. i ran into a problem last week with my rig while i was offroading. this is wat happened i was going up a steep hill in 4 low in 1st gear about to shift into 2nd but as soon as i gave it gas 1 more time a load pop underneath my truck like if i blew the motor so i slowly came down in reverse and park it and let it cool off for a bit. wat came to mind was my cat was clogged so i unbolt and nothing same sputter.....so I take it back to the shop to look more into it i replace the cap, rotor, sparkplugs and still the same thing this i check the injectors all function, 45 pds at the rail. so then i decide to do a compression test and it was 135 across on a 200k motor so not bad i replaced the distribitor nothing then the cps and the same so tommorrow im gonna replace the wires and keep checkin the truck, so after all this the truck turns on and sputters to the point where i cant drive it. i need and want my truck so i really need ur help wat it can be.


1. spark plug wires
2.check for loose grounds
3.next to do is check the timming chain replace if needed
4.?
5.?

S.O.S

has anyone gone through this ??


ALSO my truck is a 1987 Jeep Comanche 4.0 5spd

How full a tank of gas did you have?

I have seen an engine lean out and sputter and even quit going up steep inclines. Then because the engine is hot, if a slug of gas comes along, you can end up with a backfire.

oldskool023 said:

Ok well i have been searching through different sites google jeep forumes etc.. i ran into a problem last week with my rig while i was offroading. this is wat happened i was going up a steep hill in 4 low in 1st gear about to shift into 2nd but as soon as i gave it gas 1 more time a load pop underneath my truck like if i blew the motor so i slowly came down in reverse and park it and let it cool off for a bit. wat came to mind was my cat was clogged so i unbolt and nothing same sputter.....so I take it back to the shop to look more into it i replace the cap, rotor, sparkplugs and still the same thing this i check the injectors all function, 45 pds at the rail. so then i decide to do a compression test and it was 135 across on a 200k motor so not bad i replaced the distribitor nothing then the cps and the same so tommorrow im gonna replace the wires and keep checkin the truck, so after all this the truck turns on and sputters to the point where i cant drive it. i need and want my truck so i really need ur help wat it can be.


1. spark plug wires
2.check for loose grounds
3.next to do is check the timming chain replace if needed
4.?
5.?

S.O.S

has anyone gone through this ??


ALSO my truck is a 1987 Jeep Comanche 4.0 5spd

Click to expand...

you shouldn't see 45PSI at the rail on an '87-- you want 31PSI with the vacuum line on the regulator and roughly 39PSI with it disconnected and plugged off.

I'd check for a restriction in the return line if you're sure about the 45PSI

I'd look into possibly a plugged fuel filter of pump strainer if you're not so sure about the 45PSI. It's easy to stir up some sediment in the tank at steep angles.

@ old man i had about half a tank & @ shorty yes it i check it again and at the beginning it was like 37-39 and i pulled off the fuel filter and i blew through it and it flowed ? so wat should i do replace the strainer ? or fuel filter ?

Have you tried a message in a bottle?
http://www.youtube.com/watch?v=MbXWrmQW-OE

didnt work @ souske

You know, you've covered your bases on most of the typical issues.... however that fuel rail pressure does seem to be high, you might want to check vacuum lines. I wouldn't think tank strainer would be an immediate worry, but you might want to check that you're getting proper voltage to the fuel pump (I don't think this is it though, but worth checking).

I'm personally kinda've inclined to blame the O2 sensor, and while a somewhat expensive replacement, usually when I look at a jeep that's running like crap, O2 sensor is usually a welcome fix. You may want to try testing the voltages on the O2 sensor, or perhaps just start by unplugging it.

Just had this sorta issue the other day.. My jeep ran like total crap when the MAP sensor hose disconnected from my carb. It spit and sputtered real bad, refuses to start and when it did, it ran rough. U could try checkin there. It's a 2 plugs 1 plastic hose lookin fittin on the passenger side of the throttle body

I had a 97 jeep laredo. And it had the same sputtering noise even witha full tank of gas. It was my fuel pump. I need it replaced.This also happends when you run your vehical out of gas alot. it causes your pump wear and tear on it. It also might be you o2 sensor as maxxXj has mentioned.

sspring said:

I had a 97 jeep laredo. And it had the same sputtering noise even witha full tank of gas. It was my fuel pump. I need it replaced.This also happends when you run your vehical out of gas alot. it causes your pump wear and tear on it. It also might be you MAPsensor as maxxXj has mentioned.

Click to expand...

There, fixed it for ya ;-)

sspring said:

I had a 97 jeep laredo. And it had the same sputtering noise even witha full tank of gas. It was my fuel pump. I need it replaced.This also happends when you run your vehical out of gas alot. it causes your pump wear and tear on it. It also might be you o2 sensor as maxxXj has mentioned.

Click to expand...

A 97 ZJ is way different than a renix rig.

The fuel pressure should be 31 PSI, not 45. Sounds like the FPR on the front of the rail is bad, and maybe the vacuum line is bad going to it? Also the only time I had one backfire, was a loose vacuum line to the Map sensor (at the throttle body, backfire blew it off TB), so check the vacuum lines on both!!!

oldskool023 said:

Ok well i have been searching through different sites google jeep forumes etc.. i ran into a problem last week with my rig while i was offroading. this is wat happened i was going up a steep hill in 4 low in 1st gear about to shift into 2nd but as soon as i gave it gas 1 more time a load pop underneath my truck like if i blew the motor so i slowly came down in reverse and park it and let it cool off for a bit. wat came to mind was my cat was clogged so i unbolt and nothing same sputter.....so I take it back to the shop to look more into it i replace the cap, rotor, sparkplugs and still the same thing this i check the injectors all function, 45 pds at the rail. so then i decide to do a compression test and it was 135 across on a 200k motor so not bad i replaced the distribitor nothing then the cps and the same so tommorrow im gonna replace the wires and keep checkin the truck, so after all this the truck turns on and sputters to the point where i cant drive it. i need and want my truck so i really need ur help wat it can be.


1. spark plug wires
2.check for loose grounds
3.next to do is check the timming chain replace if needed
4.?
5.?

S.O.S

has anyone gone through this ??


ALSO my truck is a 1987 Jeep Comanche 4.0 5spd

Click to expand...