My son's ranger is having an issue. At start up in the morning, it has a rougher than normal idle. In the evening, after work, he said starts fine. Just an issue in the a.m.. He did have the radiator and some sensor replaced at just under $900.. It's a 99 with 182k miles. He also said that while driving home, going up a long hill on the highway, it seemed like the transmissoin was slipping. Not sure exactly what was happening, we're going to try and reproduce the issue this weekend, but was hoping someone would have an idea on the rough idle in the mornings.

 

All gasoline engines need to be "Choked" when cold
Choke, in this case, means to run Rich with high idle and advanced spark

The computer does this on fuel injected engines, on carb engines there was a "choke plate" that did this

The computer needs to know engine/coolant temp so it can set the Choke and how much choke to set
It uses the ECT(engine coolant temp) sensor for this, no connection to dash board temp gauge.

IF..........engine has a higher idle cold then ECT sensor and Choke is probably working


So this problem started after he had the working done?
Right after, or its been a month or two?

Get the bill and list the sensors that were replaced, its important

Only sensors that need to be replaced are the O2 sensors, they use a chemical reaction to detect oxygen in the exhaust and they use up the chemicals, same as a battery does

Any sensor can fail, like the ECT sensor

MAF sensor can be cleaned

 

Ended up being the #6 spark plug. Fixed the rough idle at start up and the stutter at shifts under load.

Yesterday, the oil pressure gauge went wacky, bouncing between both pegs about 20 times a second, the temp gauge pegged hot, and the check gauge light came on. Pulled the radiator over flow tank cap and it was fullof slughe and brown liquid. Pulled the dipstick, the oil looks ok. So back to the shop it went.

Time to upgrade to Mustang.

 

Mustang is a downgrade, but still a serviceable vehicle