Question- 86 w/302
Thread Starter
|
Junior User
Joined: Dec 2003
Posts: 52
Likes: 0
From: Dallas, TX
Question- 86 w/302
I am fairly new to this board. I am rather diesel saavy, but have very little experience with FI 302. The truck is an 86 with auto. It just got a new PCM. It also has no EGR components left on it, and has true straight piped duals. I have several questions for you guys, and would most definately appreciate any info you all could provide.
1-I don't believe the IAC is fuctioning properly. The engine tends to surge at idle and will not hold idle in gear. I have done all tests as listed in the Haynes manual, and come up with no solution to my problem. Any ideas? I have temporarily disconnected the IAC and bumped up the idle screw on the intake, and the truck seems to idle fine, but I am worried about cold starting, etc...
2-While driving, the tranny seems to shift very late into 3rd gear. RPMS will go very high say 3500-4000 under normal, not hot rodding, driving conditions. Fluid levels okay at hot idle and shifts are just a little too firm in other gears.
3-Would installing a pair of 2 1/2 inch flowmsater 40 series mufflers(vs. no mufflers at all right now) help at all with the idle problem by adding a little back pressure to the system?
4-Does the PCM see the tach readings to set the idle? My tach is not working properly. It floats around 1000 until I get some speed going.
5-Does the PCM control timing at all?
Again I would appreciate any input, and may post with some other question later on
1-I don't believe the IAC is fuctioning properly. The engine tends to surge at idle and will not hold idle in gear. I have done all tests as listed in the Haynes manual, and come up with no solution to my problem. Any ideas? I have temporarily disconnected the IAC and bumped up the idle screw on the intake, and the truck seems to idle fine, but I am worried about cold starting, etc...
2-While driving, the tranny seems to shift very late into 3rd gear. RPMS will go very high say 3500-4000 under normal, not hot rodding, driving conditions. Fluid levels okay at hot idle and shifts are just a little too firm in other gears.
3-Would installing a pair of 2 1/2 inch flowmsater 40 series mufflers(vs. no mufflers at all right now) help at all with the idle problem by adding a little back pressure to the system?
4-Does the PCM see the tach readings to set the idle? My tach is not working properly. It floats around 1000 until I get some speed going.
5-Does the PCM control timing at all?
Again I would appreciate any input, and may post with some other question later on
Elder User
Joined: Apr 2003
Posts: 627
Likes: 1
why not go to the wreckers and get a few IACs and try them until the surging stops and I have found the tps more at fault for surging have you checked the voltage on it or tried others, not sure what tranny you have but the tps controls the shifting on the E4od while the throttle valve cable does on the Aod it should normally have very little freeplay experimant with it a bit.
Thread Starter
|
Junior User
Joined: Dec 2003
Posts: 52
Likes: 0
From: Dallas, TX
I found the problem with the tranny. The TV cable was way way too tight, causing the tranny to think it was being kicked into passing gear. Got that one solved. Now, i need to kill the surging problem and get her to idle right.
