[fatboyracing]

Hey guys, I've got a 93 wrangler with a 2.5l and a 5 speed. While cruising down the road at a steady speed, it will spit and sputter like it is going to die, if I go to the floor with it, it straightens out and runs fine, try to hold it at a steady speed and a few seconds later it does the same thing. This only happens when it warms up, I can crank it and drive it for 30 minutes with no issues, but once it warms up, it is impossible to maintain a steady speed. And this can be any speed. It always idles fine and runs great at WOT.

 

[0III0forlife]

Could be a multitude of things. When was the last time the TPS (Throttle Positioning Sensor) was changed? Any vacuum leaks? How many miles are on it?

Sounds like if it is doing it at any speed, except for idle and WOT, I would look into it being a sensor. Is it giving any codes?

 

[fatboyracing]

No codes, it has 188k on the clock, new fuel pump, new O2 sensor, new plugs and wires, I went through all of the vacuum lines and didn't find any leaks, I've cleaned the throttle body and tried a new air filter. I guess a tps is my next step, I'll try that tomorrow. Thanks for the input, maybe I can get it lined out soon.

 

[Michael_Larsen]

My 89 is doing the same exact thing. It is frustrating as all get-out. I found that the coil wire on my distributor cap was just sitting there, not clicked on. That seemed to fix it but it was only a coincidence because today it did the same thing when it warmed up. Same engine. 132K miles. New plugs, wires, air cleaner, and no apparent vacuum leaks. Throttle body looks great and everything looks clean. Tics me off.

 

[Slowfoot]

Vapor lock maybe??

 

[peety]

Check the Crank sensor spec, it should have 200-275 ohm's of resistance and develop about 5v when cranking the engine over.
You can also try disconnecting the O2 sensor and driving it, just because it's new doesnt mean that is isn't faulty

 

[Michael_Larsen]

Check the Crank sensor spec, it should have 200-275 ohm's of resistance and develop about 5v when cranking the engine over.
You can also try disconnecting the O2 sensor and driving it, just because it's new doesnt mean that is isn't faulty

Where is the crank sensor located?

 

[peety]

On the Bell housing, drivers side. If you look at the trans from the rear, it's at about 11 o'clock. Trace the wire to the connector, this will be on the passenger side back near the firewall. It is a three pin connector.

 

[Michael_Larsen]

On the Bell housing, drivers side. If you look at the trans from the rear, it's at about 11 o'clock. Trace the wire to the connector, this will be on the passenger side back near the firewall. It is a three pin connector.

Awesome! Thanks. I'll check it out post-haste!!

 

[Michigan jeeper]

Injectors leaking? Clogged maybe?

 

[rockclimbingchris]

[QUOTE="fatboyracing, post: 7223113, member: 308177"] [B]Hey guys, I've got a 93 wrangler with a 2.5l and a 5 speed. While cruising down the road at a steady speed, it will spit and sputter like it is going to die, if I go to the floor with it, it straightens out and runs fine, try to hold it at a steady speed and a few seconds later it does the same thing. This only happens when it warms up, I can crank it and drive it for 30 minutes with no issues, but once it warms up, it is impossible to maintain a steady speed. And this can be any speed. It always idles fine and runs great at WOT.[/B] [/QUOTE] I've got all these exact same problems. What fixed yours?

 

[Luckymac]

Welcome to the Forum @rockclimbingchris

If you hold your cursor over the avatar of the person you want to communicate with you can see the last time they were on the forum. In this case, fatboyracing asked his question, got one response then thanked the first member that responded and hasn't been back since. That was over nine years ago.

It's best if you begin your own thread, describing your Jeep (year, engine/transmission and any mods you know of) and what you've done to try to fix the issue.

Here's a link we often refer new members to...

A better way to get help in the YJ Tech Forum

Originally posted in the General Discussion Forum by NonRubicon in May 2014. It's every bit as relevant today as it was then. ....................................................................................................... I think there are a few things members here can do to help...

www.wranglerforum.com

Good Luck, L.M.

 

[Old Dogger]

[QUOTE="fatboyracing, post: 7223113, member: 308177"] [B]Hey guys, I've got a 93 wrangler with a 2.5l and a 5 speed. While cruising down the road at a steady speed, it will spit and sputter like it is going to die, if I go to the floor with it, it straightens out and runs fine, try to hold it at a steady speed and a few seconds later it does the same thing. This only happens when it warms up, I can crank it and drive it for 30 minutes with no issues, but once it warms up, it is impossible to maintain a steady speed. And this can be any speed. It always idles fine and runs great at WOT.[/B] [/QUOTE] I've got all these exact same problems. What fixed yours?

Welcome to the Forum!

 

[Digger84]

If your year has 2.5 has 4 separate fuel injectors and you have an rpm specific miss/stumble first check injector harness plug order
Something about the 2.5 injector harness layout seems to make people plug harness connector 3 into injector 4 and harness connector 4 into injector 3
Still runs ok as timing of fuel entry into cylinder is by intake valve opening not injector firing but messing up injector firing sequence tends to produce an rpm specific miss/stumble
You check by comparing harness wire colors at injector plugs to FSM if not on correct injectors just move them to correct injectors