Q: Car is running rich - 1990 Jeep Wrangler

asked by on

Hoping to get some direction here. Im good with basic mechanical fixes but not a mechanic. More of a hobbyist.

Bought a 90 over the summer. Previous owner did a Howell TBI conversion and got rid of the carb. I knew it was running a little rich when I got it. Every once in a while it gives a problem starting (about 1once every 100 starts). The easiest way it seems to get it started is to remove the air filter. Im not too worried about that but figured I would add that for context. Also the floor seems to get hot when driving for a while.

Now that its gotten cold out I have the following happening:

Starts fine. Runs very rough until warm Has no power almost at all until warm

Any idea on what may be causing this would be really appreciated. If more information is needed let me know and I'll be happy to provide it.

My car has 120000 miles.
My car has an automatic transmission.

Starting any engine in cold weather is never an easy task as they simply do not like cold weather and do not run well in it. When you first go to start your Jeep on a cold morning and turn the key, there is a coolant temperature sensor which reads the temperature of the coolant relaying this information back to the computer.

The computer then makes an adjustment to the fueling of the motor to enrich the fuel mixture needed. This happens when the air is cool due to the density of the air requiring more fuel to maintain the same amount of power.

To avoid any unnecessary repairs, I would highly recommend having an expert from YourMechanic come to your location to diagnose and service your cold start injection system firsthand.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Car is running rich - 1990 Jeep Wrangler

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Got a check engine code of 1899

Hello. The symptoms you describe can be caused by a few different things. If you are showing code P1899, for a park / neutral safety switch that is stuck in gear then it may be possible that the switch needs...

Q: Put key in ignition. Lights and everything come on for a second, then went off as I turned the key. Now no power, key stuck

Hi, thanks for writing in. This sounds like your battery cable connections are corroded or loose at the battery. Try to see if the battery connections are loose by wiggling them and see if power returns. If power returns, then...

Q: Putting in a new battery but the horn, lights, and wipers come on and won't stop.

Check the light switch, the horn switch, and wiper switch. If the switches are not working, then they will need to be replaced. If the switches are good, then there is a loose or broken ground wire on the steering...

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...