1988 2.9L running rough when warm..

[Bfg95 88 Ranger]

Hello

I'm having this issue with my 1988 Ranger Xlt 2.9, Starts just fine in cold or hot weather but after 10-15 min driving (starting to get to operating tempeture) it starts to die and go rough and starts to spit small ammouth of black smoke out of the exhaust, but if i floor it it changes gear and goes just how it should but as soon as i hold it to normal speed 80km/t (50mph) it starts to go rough again..

Anyone know what could be wrong? haven't been changing anything yet.

 

[Shoddy Cologne]

Could be a number of things. My fuel pump went kinda like that lol. Dies it start good when the engine is warm?

Sent from my LGL16C using Tapatalk

 

[Bfg95 88 Ranger]

Could be a number of things. My fuel pump went kinda like that lol. Dies it start good when the engine is warm?

Sent from my LGL16C using Tapatalk

hmm okei, yeah it starts right off when it's warm. sometimes it goes as it should, but it use to stand there and sound rough almost dying.

Accelerate just fine until i stop pusing it to 50mph and then it starts to smoke a little and starts to spitting a little.. can't figure out what it could be :/

 

[rusty ol ranger]

Sounds like a coolant temp sensor or possibly an O2...is it throwing any codes?

 

[Bfg95 88 Ranger]

Hmm.. Yeah could be the O2 sensor.. i haven't tried doing that code testing ( not sure how to do it on this one), it also uses alot of fuel but might be because of the problem.

 

[enjr44]

My first and easy guess is the engine temperature sensor and they are cheap enough. The two wire sensor. The one wire sensor is for the gauge.

The ETS is used to determine when the computer can lean out the fuel ratio for a warm engine.

 

[Bfg95 88 Ranger]

My first and easy guess is the engine temperature sensor and they are cheap enough. The two wire sensor. The one wire sensor is for the gauge.

The ETS is used to determine when the computer can lean out the fuel ratio for a warm engine.

Yeah could be that one too, I also noticed that he can start going rough already when i fire it up when the engines cold and it goes up to 1500rpm and stays like that for 10sec - 30sec and then to 1000(normal rpm) , and then sometimes starts to go down to 500 and jump to 800 and back to 500, keeps on like that until it dies or goes back to 1000 then it sounds just fine (cold engine)

 

[Bfg95 88 Ranger]

I tried to disconnect the Oxygen sensor, and he ran just fine with some driving around and got it to normal temperature, when I was going to park it, he started to go a little rough, I gave it some throttle 2 times and the Check Engine light came on, but it ran just fine after that. the check engine light came of after i connected O2 sensor again.

I suggest the O2 sensor is the problem? or anyone have any other ideas?