87 2.9l a4ld to fm146 swap post ?s

[Zejokee]

Ok I got a few questions pertaining to the transmission swap I just did. The tech page says you need to re-time you engine is this correct and what is the logic behind this. I know the transmissions work differently on the engine. I grab the pcm/ecm from the donor vehicle and swapped it out with mine. It also seems like I am running at high rpms while idling and holding the clutch. Usually around 1900rpm. It drives great and shifts great. I am also having a check engine light come on after about 5 mins of driving or so. Could this be a sensor issue b/c of the swap?

 

[Zejokee]

Bump? Any ideas or tips?

 

[The_Dealer]

try to retime it, but i bet the problem is the auto ecm with the 5spd. get a 5spd pcm n u should be good to go

 

[Zejokee]

Well I already grab the computer that is under the passenger side dash from the Bronco I pulled the trans out of and installed it in my ranger. Is there two separate ones on the 87? I am still not to familiar with my Ranger yet. I am use to working on Jeeps.

 

[Zejokee]

bump? Any other suggestions?

 

[mhughes165]

automatic trucks are designed to idle higher then manual trucks, its only a 50 rpm difference though IIRC

 

[Zejokee]

I understand that but it is throwing a check engine light and I would like it to idle normally. I have noticed that it only throws a check engine light if I am accelerating a lot like in the city and my rpms are constantly dropping below 1800rpm. If I am cruising in 5 gear and my rpms are around 2000rpm the check engine light never comes on.