so i got a new trans in.. at low cruise say around 15 or so it surges like its shifting 1-2 and back again.. also sometimes it will pop thru the tb too. and at idle in park will start to idle real ruff and get a loud sucking noise and possibly die.....

i know i need a new iac and plan on picking one up today or tomorrow.. do any of you think this will fix my issue? talked to a buddy today and he seems to think that it will solve my issues....

 

The IAC dosn't sound like your problem, and for reference, I just had this problem and it ended up being my crankshaft position sensor.

Seeing as you said you had a transmition popped in, it could have been hit or crushed while installing it, it's in a sucking location, but I'd like someone else to confirm this.

IAC would only affect idle though, and the sucking noise is the IAC opening, so it possibly could be working correctly, I am not sure how to test it.

 

maybe some vaccume lines? im no tranny geek but worth a check

 

could it be the plenum?

With that siad maybe it affect the 02 sensor and cat?


i may be off, but worth a check.

 

Isnt it always the plenum?

Adjust your TV (Throttle Valve) cable.

 

all thats been done already... and the truck did this before the trans went out.... i got a new iac today for like 32$ so ill throw that in and see. cant hurt nothing,

 

For the surge, i was told by a couple people that a broken accumulator spring (in the valve body) will cause that.

for the idle issue, that sounds like the IAC to me.

 

the surging only happens when say going about 10mph.. thats why i was thinking iac.... no springs broke new trans everything is new.. all rebuilt and all upgrades done.

 

I just had the same problem with my 01. Pre Cat O2 sensor turned out to be the problem.

 

thats intresting.. on the way home tonight at about 65-70 it started hesitating backfiring missing and crap.. then when i floor it it would clear out. but as soon as i would let off to go back to 65 or so it would do it all over.. wide open it would run like a raped ape but other then that it would cut out and crap... iac is replaced and still have idleing issues to. so i have a truck made in 12-96 so what do people think? map sensor? crank sensor? or throttle position sensor or as twisted said pre cat o2?


need help as this is getting annoying.