1994 ranger with CEL and some other issues

[quinn2]

Hi, I recently bought a 94 Ranger with the 4.0 and 160k miles. I'm hoping to get some help with a few things.

1, on a cold start, it'll rev up to 2500rpm and then drop after a second or two. is there any way to fix this or is it normal? the warmer the truck is the less it revs up

2, I pulled a few codes, 189 and 543. What should I replace to try and fix the 189? it says its a "Fuel system at rich adaptive limit at partial throttle/system lean." the truck runs normally to me so idk what the issue is.

thanks

 

[4x4junkie]

Normal cold-start rev-up should be 1200-1500 RPM.
It's been a long time since I had a similar issue on mine, but I want to say it was the time I found the vacuum hose to the cruise control solenoid disconnected (rodents maybe? it was undamaged, just unhooked), Plugging it back on solved whatever issue I had at the time (I think it was when it was fast-revving on cold starts... it would sometimes die right afterward too).

Something to check for, anyway (vacuum leak).


Welcome to TRS.

 

[rumblecloud]

A a couple of things to check after you have resolved the possibility of a vacuum leak:
IAC and/or TPS.
Intake Air Control can be removed and cleaned.
Throttle Position Sensor can be checked.

Personally, a little higher rpm at cold start wouldn't give me a cause for concern ---
I'd just be happy it started at all