I have a 1994 D21 pickup 2WD KA engine and recently the check engine light came on and engine would not rev past 2500 RPMS and pulled the code and got a 12 which is a MAF problem. I bought another MAF sensor from the junk yard and put it on and the truck will not staying running now in city traffic but on the highway the truck runs pretty good and gets over 2500 RMP but as soon as I decelerate starts running rough in the lower RMP 's but dies if I do not keep reving the engine but no check engine light. I also ran a ground wire on the new MAF to the battery and the truck will idle yet the truck will return to not going past the 2500 RPM.
I have checked the following on my truck:
Replaced MAF sensor with one from a junkyard
Tested old and new MAF and did notice that I couldn't get full continuity between port A on MAF and ECM.
Tested TPS,Fuel Pressure, IACV, Temp. Sensor
Clean Throttle body & MAF
Check the EGR valve
Checked MAF Relay
Checked Distibutor & Distributor Cap
Checked for Vacuum leaks
Checked spark plugs and they are carboned up.
I am at a loss on what to the problem could be.
I have read a ton of posts on this forum and hope someone can help me. I am ready to pull my hair out.
Thanks
