Seems to happen in the 2500-3000 RPM range. More noticeable when car is cold, car bogs down, then starts ripping again. New O2 sensor, MAF works, coolant temp sensor seems to work (runs like poo when i disconnect it. Car is a 1991 loyale. Would the throttle position sensor have something to do with this? What does the throttle position sensor even do? Any advice would be appreciated! Thanks 

Hi there!

 

I just read somewhere on here about MAF Cleaning. My car had similar bogging in accelerating definitely when cold, and I sprayed some carb/throttle cleaner through the MAF sensor. It definitely helped out with "cold start and drive it" type of driving. Like when you're running late and hop in and go. I think the MAF sensor got dirty from age. Try spraying the heck out of the sensor and then reconnect it and fire it up. It might take a few turns to burn off the cleaner. Then next time you cold start it, drive it immediately and see if its better now.

Usually this type of symptom is an ignition problem. Look for arcing wires or cracked plugs, etc.

 

GD

Here's a brief on TPS:

 

http://www.ultimatesubaru.org/forum/topic/76637-have-you-checked-your-throttle-position-sensor-today/?do=findComment&comment=636556

 

I think it's worth checking, I assume there's no CEL codes.

I would also run a vacuum test on the engine and see what it reveals.

Edited March 6, 20179 yr by Dee2