88fox50

ok im still baffled, the car has a slight miss of some kind , electrical issue i think...if you press the gas pedal and hold it at 2000 rpm it will sit there for a min..then slowly start to climb in rpm on its own and when it settles in it will occasionaly miss ..then at idle, sometimes it is all over the board... it will idle fine for a minute,,,then rev up to 1200 stay for a minute..then fall down to 700and chugg for a sec then back to 1000...and sometimes its not as bad.. ...it drives pretty good with decent throttle response but i know something is wrong .im stuck

so, so far i have done the following to resolve..

plugs, wires, cap & rotor, fuel filter, IAC valve, Coil, checked base timing =10*, checked vacume hoses from MAP to upper plenum, ...

here is a video to help explain what i mean....its about 4.48min long cuz my camera wont break the shots into seperate files so i can just post the important ones ...sorry - http://www.youtube.com/watch?v=yvCMOup_OL0

aode08

do you have a MAF SENSOR and is it mounted vertically and cleaned with electrical contact spray on the inside ?

aode08

checked vacume hoses from MAP to upper plenum

???MAP Dont have a hose to it just vent????? unless the 88 is different then the rest

ttoppedgt

replace the tfi module on the distributer also if u have another distributer install that and see what it does i had this problem on a 91 ho motor also my pops had the same thing happen in his 4x4 88 pickup went nuts tring to fix it replaced everything and all it was was the tfi unit and or distributer check it out and goodluck

mjr46

I wouldn't be so concerned about the idle hang ....that is often a normal characteristic but do make sure the throttle body is clean and free of any carbon build up around the throttle plate and or behind it.......run a koeo/koer test and check for codes

Joel5.0

Idle is set too high........ suggest a Base Idle Reset Procedure + a DIY KOEO/KOER/Cylinder Balance Self-Test as MJ suggested above. If your setup is MAF, the VSS will cause the idle to stay higer than the idle setting as long as the MPH reading is above 6 MPH.... that is the "dashpot" function at work, and it is normal. LUK what the self tests show.

uedlose

Whats your TPS voltage set at?and is it good?

88fox50

you know what, that went thru my mind actually...i found one at napa for 40 bucks so i will try that too.. thanks!

88fox50

great info, do i need a jumper for the test then? something i can pick up at the parts store? thanks for your help

88fox50

yea my MAP sensor is mounted to the firewall and has 1 vac line running to the intake.