97 TJ sputters between 2900&3000 RPM if I am light on the throttle it worse than if I’m accelerating quickly 2.5 engine. New O2 sensor new TOS and MAP sensor
97 TJ sputters between 2900 & 3000 RPM
- Thread starter Srowland
- Start date
Correction the post should say between 2800 rpm and 3000 if that makes a difference
Unfortunately that year does not have a shader valve I was thinking about cutting in a tee in the fuel hose
Get one of these...you can either install a Schrader valve into the 1/8" port or just install a fuel gauge straight on to the rail.
https://www.racetronix.biz/p/adapter-qdf-5-16qdm-5-16-1-8-port/qda-56f56mp
-Mac
https://www.racetronix.biz/p/adapter-qdf-5-16qdm-5-16-1-8-port/qda-56f56mp
-Mac
TJRick
TJ Enthusiast
I just went through this exact same thing on my 1998 Jeep ZJ with the 4.0 engine.
Except I also cleaned the throttle body and the IAC valve trying to find the problem.
It ended up being a fuel pump that was putting out about half of what it should have.
Update on the pressure at idle and while running it sits around 44psi pretty steady when it misses the pressure drops to what I can’t really say it happens very fast but at least 10psi. And the part you recommend worked great. Thanks
Interesting. Wonder what's causing the intermittent pressure drop. Maybe an injector not holding pressure. Hmm.
-Mac
-Mac
swtrailboss
Member
Possibly the pump is worn and just can’t keep up with the volume demand when foot is on the accelerator. Have you verified if the RPM range is higher than 3000 does this pressure still drop to the 10 psi range? Even if it seems to be running normal ?
swtrailboss
Member
Bouncing between what readings? So what you are saying is it’s more noticeable between 2800 and 3000rpm but the fuel pressure will still drop into the 10 psi range when you are hard on the throttle and above the trouble rpm range?
Bouncing between 34 and 44. But the pressure gauge probably can’t react fast enough to show a good low end pressure
I just replaced the fuel pump on the 97 TJ. Unfortunately it did not solve the problem. Any ideas
What fuel pump did you install? What brand of O2 sensors did you install?
What's the fuel pressure? Is it holding pressure after shut down? Does it still drop pressure as RPMs increase?
Any codes? A Bluetooth ODB reader for $30 and Torque Lite will read live data. Where are your fuel trims? O2 voltages? Vacuum?
-Mac
What's the fuel pressure? Is it holding pressure after shut down? Does it still drop pressure as RPMs increase?
Any codes? A Bluetooth ODB reader for $30 and Torque Lite will read live data. Where are your fuel trims? O2 voltages? Vacuum?
-Mac
Napa fuel pump. O2 sensor OEM from jeep dealership.
Fuel trims?? O2 voltage?? I have no idea
Need to read live ODB data. Bluetooth dongle and Torque Lite app for your smart phone.
https://www.amazon.com/gp/aw/d/B06XGBKG8X?tag=wranglerorg-20
And fuel pressure...need to know what those numbers are.
-Mac
I will pick up a scanner and recheck fuel pressure. Thanks
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