I know this has been talked alot but Im at my wits end. I replaced a fuel pump on my 2001 cherokee an Airtec I knew it wasnt the most popular but at the time it was all that was available. It started and worked great for less than 2 weeks then started acting like old one. Then it got worse as it would barely start and stumble and you had to rev it up to get an idle. I knew I had a injector problem so I replaced them It helped with the starting but still had to crank it alot to start. Well now Im getting tired of this so I get a Carter pump assembly from Rock auto. After install it wasnt much better it starts but it takes some cranking. Now what is with these pumps is it the quality manufacture I dont know anyone else go through this. With old pump I once just disconnected the battery and it started and ran fine for a few weeks then crapped out again. Is there a chance a problem with pcm. I have a 99 also not nearly as bad as this 01.

 

Nobody has had a hard starting problem. Everything has been changed just wondering if there could be a problem with the computor. Or is there a prefered fuel pump assembly. It started great for a while with the airtech then it just went bad. The carter I put in doesent seem to hold pressure either.

 

Any codes? No idle sounds more like issues with the IAC. Whats the fuel pressure in psi? Ever perform a compression test to rule out dead cylinder(s)?

 

If you've gone through 2 or 3 fuel pumps and they all act the same, then it's not the fuel pump.

Not unless you have an extraordinarily dirty/rusty fuel tank that is clogging up the filter.

 

cant rule that out completely... i have seen it..

 

Tank is plastic. Filter is not plugged. Fuel pressure on start up and idle is good. It does bleed down some I will time it. It is unpredictible when cranking sometimes it lights off in a couple and other your cranking 4-5 revalutions. It starts just very irritating. It was real nice like a new car than after 2 weeks the Airtek failed. Carter starts is just not right like a new pump should be. I read off another thread where some one stated there is a tie in to how the a/c is pressurized and working properly. I fail to see how that works. Though the a/c pressure has fallen and not blowing cold.

 

Quote:"It is unpredictible when cranking sometimes it lights off in a couple and other your cranking 4-5 revalutions."

I don't see where this is unusual for an XJ 4.0.