4x4utahcherokee

Here is the problem: When the jeep has started, it idles fine, after rolling about 100 feet at normal suburb speed (around 2000 RPM), the engine sputters and backfires in the intake i think and has problems accelerating: The engine doesn't stop, it just has a hard time providing power. The RPM acts accordingly to the engine perceived rev. If I gently insist on pressing down on the accelerator, the engine complains and doesn't seem to appreciate it.
Gently removing my foot from the accelerator and pressing slowly back (a few times) will eventually solve the problem. Another way that solved the problem is if I step completely on the accelerator. The engine responds with full power and full acceleration (making the first method the preferred way in my quiet suburb).
The engine has always been maintained. Regular checkup and all. I recently replaced plugs, rotor, cap, wires . I explained the issue to the mechanic and he has pulled the code DTC P1282 from the computer.
The code has a wide spectrum and since a fuel pump is costly, he proceeded with a few diagnostics, To make sure that the electrical wires to the fuel pump were good, a electrical spy (a led connected at the end of the wire) told us that the voltage to the pump was okay.
Also when I turn the key to on, I hear the pump humming as it has always done. We are now trying to find out if the fuel pump spits out the proper pressure, it is our next step. I was wondering if you ever saw this before and if you could help.

• 1997 Jeep Cherokee Sport 4WD
• 4.0 liter I6 engine
• Automatic transmission
• 160,000miles
• Fuel Injection
• P/S, A/C, Cruise control
• Rack and pinion steering

4x4utahcherokee

68 views and no one has any clue or guess?

joelfett

Have you checked the TPS? You have the exact same symptoms that I had about a year ago with my 92 XJ. I replaced the TPS and my problem was solved. Hope this helps.

dyte2004

could be the tps

4x4utahcherokee

I'm gonna replace that this weekend. i've been getting a few hits on other sites saying crankshaft position sensor, o2 sensors and map sensor. I'm just trying to get it narrowed down to one maybe two possibilities since I don't have 400-500bucks to replace all of them at once. Trust me if I did have the money I'd just do it all. lol My cousin said don't fix it if it ain't broke but being that it has 160k on it I like to call it preventative maintenance.

Mr2Jeep

I'd also go with the TPS.

4x4utahcherokee

Just went and bought a tps sensor on my lunch. I'll install it tonight and let you guys know on monday when I have access to the net. Hopefully it works and can help someone else out in the future with this post cause I've seen a few posts out there with similar problems. Thanks for the help guys and wish me luck.

captainwoot

Just another thought I had simliar problems with mine....upstream o2 sensor(also a little corrosion on the harness side of plug inside the connector) search my threads ,I posted the findings from another site, it fixed mine!

4x4utahcherokee

K so I installed the tps friday after I got off work. My jeep ran alot better but still had the sputter problem a few minutes after starting it. My cousin recommended I clean the idle air control sensor so I went and got some mass air flow sensor cleaner and cleaned the iac which made my jeep start running like crap again. One of my buddies unplugged my map sensor and that leveled my idle out and so that makes me think that my map is gone and possibly my iac. I unhooked my battery hooked it back up and ran it for the rest of the weekend. My CEL came on so I did the key trick to check the codes and got a 21 which means now my o2 sensor isn't working. On the positive side this weekend I changed out my transmission filter and installed a pinion seal in my front axle so I'm finally not living evidence of where I've been. lol Anyway so I guess my next step in my troubleshooting is MAP, IAC, and o2 sensor replacement. It could possibly have to do with my downstream o2 sensor. i replaced it a month ago but they only had the universal connection. I'm starting to think my butt splices didn't hold up. I'm gonna have to borrow a soldering gun and fix those and hopefully that does the trick as far as my o2 sensor goes. Thanks for all the ideas guys and keep coming at me with ideas cause anythings possible when it comes to sensors. I like my 97 cherokee but I think I like my old 90 cherokee better. It seems the obd1's aren't as picky when it comes to sensors and electrical. I owned my old one for 3 years and never had to replace any sensors and it ran like a champ. I've owned this jeep a year and have had nothing but one small issue after another.

rich

could be all the above you listed,but a universal os is a bad idea the best ones are from the dealer unfortunally.Check to see if the little hose under your map sensor is plugged up.(any junkyards around you maybe you can get those parts cheap enough to try out)map,iac,etc good luck

4x4utahcherokee

I checked the little hose to my map when i checked my IAC. it was good. The only reason why I bought a universal o2 was cause the previous owner decided to cut the connector off. To save the 20 bucks between universal and oem i guess. Another problem I'm having is that after I've been driving around and then my jeep idles a little while like at a drivethrough or waiting for someone my engine seems like its starting to bog and sputter like it's starting to flood. Could that just be because of the sensors or do you think its something more like leaking/bad injectors? Thanks for your help guys and keep the ideas coming.

4jeepers

Before you replace the TPS make sure that it is not only out of adjustment. There are websites that will show you how to adjust with a volt/ohm meter!

rich

Posable dirty injector, carbon buildup on vavles ever try seafoam?

01LimitedXJ

verify 02's are working, and also verify that the fuse to the 02's hasnt blown.

4x4utahcherokee

As far as the tps I don't think you can adjust my year. I believe from what I've read so far that the ecm does the adjusting for my year.

I have used seafoam before but not in about 6 months and I never put it in my tank just in the throttle body so I'll probably grab some after work and give it a shot.

I actually checked my o2 fuses last week but I wasn't getting codes for that at the time. I did unplug my upstream o2 sensor to check for corrosion or grime in the connection but didn't think to recheck my fuses. I guess it's time to check them again huh. I'll check them out after work.