Ive got a problem with my 92 wrangler sahara. Its got the 4.0 h.o. Under moderate to heavy acceleration in any gear I get what seems to be lack of fuel flow to where sometimes I get excessive jerking in my whole drive train. This problem is very random and does'nt happen all the time. I believe that it is fuel related because of the drop in rpms. I have already replaced the m.a.p sensor but to no avail the prob. is still there, just not as constant. I dont believe it to be the t.p.s cause at idle the rpms stay an accurate 650. Any help in this dilema would be greatly appreciated. This does not happen under light acceleation. I cant figure it out..
acceleration prob. 92yj 4.0
- Thread starter CJ2YJ
- Start date
Collin the Hen
New member
Does it happen at all while cruising? If a distributor is bad they sometimes jerk like it looses fuel for a second.
Bounty__Hunter
Super Moderator
TPS would be my guess, your performance at idle is not related to the TPS condition. Idle is controlled by the IAC motor.
Also consider replacing your fuel filter and having your injectors professionally serviced.
Also consider replacing your fuel filter and having your injectors professionally serviced.
My distributer seems to be fine I think.
Collin the Hen
New member
It very well may be. That was just the first thing that popped into my mind. I wish I could help you with the possible other filter, but I've never messed with a 4.0. I have a gutted 258, so the only sensor is my brain deciding when to turn off my choke.
I thank you guys for your help. Hopefully I can diagnose it soon!!
Thanks for the help Collin.I should have never left the CJs.
SteelHeadz
Super Moderator
The Filter under the driver side frame rail is the only service filter for the fuel. the next filter is inside the fuel tank which is called a Strainer. if you have access to a fuel pressure gauge, that will be the best way to check for fuel delivery issues.
Never checked fuel pressure before.How easy is it to do and how?:?:
SteelHeadz
Super Moderator
The fuel pressure test port is located at the fuel rail. it looks like a tire valve. you will need a fuel pressure gauge that will thread into this fitting. Be careful when you screw or unscrew the gauge, the fuel rail is pressurized and the fuel may squirt or spray all over your face. use a rag on top of the fitting just in case...Turn the key on and start the engine. monitor the fuel pressure reading on the gauge. it should be at least 35psi @idle. watch for fluctuation as well..
Should I raise the rpms while doing this to look for fluctuation or just at idle? I appreciate your help!! Thank you
Bounty__Hunter
Super Moderator
Check the fuel pressure two ways at idle, once with everything hooked up and then again after pulling the vacuum line to the fuel pressure regulator (at the end of the fuel rail).
I really thank you for your help!! Will try this first thing in the morn. hopefully its not the sending unit. :-|
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