ihblarp
NAXJA Forum User
- Location
- Las Cruces, NM
My 89 4.0l has been idling rough and stumbing right off idle and all the way through the rpm range. stutters so bad that sometimes it takes more than a mile or so to get up to 50-55 mph. Happens more often than not, but some times i'll get in start it (cold motor) and it will run great for the first few minuts but then starts stumbling and being cranky. tps checks out fine (4.9v in .7v out), but i just ran a fuel pressure test and something seems funky.
Start-up fuel pressure is 30psi
drops to 20-23 psi (no change with disconnecting p. regulator)
turn off engine and pressure drops to 0 in less than 10 secs
Does this sound like a faulty pump to you guys. I've replaced the pump twice in the two years I've had this jeep but it never acted like this. Usually when the pump went south the engine would just start and die, or not even run.
Ive been told it could be the egr valve, but without a vaccum pump and guage i dont know.
Should i just throw yet another pump at it and hope for the best or continue searching and testing things? (ok, maybe this isn't such a quick question but still any help would be much apreciated)
Start-up fuel pressure is 30psi
drops to 20-23 psi (no change with disconnecting p. regulator)
turn off engine and pressure drops to 0 in less than 10 secs
Does this sound like a faulty pump to you guys. I've replaced the pump twice in the two years I've had this jeep but it never acted like this. Usually when the pump went south the engine would just start and die, or not even run.
Ive been told it could be the egr valve, but without a vaccum pump and guage i dont know.
Should i just throw yet another pump at it and hope for the best or continue searching and testing things? (ok, maybe this isn't such a quick question but still any help would be much apreciated)