Azrael91966669

i have a 91 tpi non adjustible tps but yet when i 1st installed it i did have to make some adjustments to get it to idle correctly
i just wonder if it really matters how you line up the tps on the 2 bolts or not
its not like the older type where it moves alot but diffently dose make a differance if its not lined up perfectly or to far up the idle bounces up and down
if its pointed to far down it holds idle at 1300 centering it it will idle flawlessly at 800

i just wonder if this is why people with speed density do sometimes have issues with tps after installing a new one
i didnt hook up a volt meter but from what i can tell it dose seem to have to be placed correctly even if not adjustible

also when i got my tpi i was told to use a tpi iac looks the same as the tbi iac but the tpi iac dosnt seem to react correctly currently im useing the tbi iac with no issues
the tpi iac would hold the rpms up way to high comeing to a stop or when i would floor it from a stop it would make loud sucking sound "loud wooop"
for a half sec then take off fixxed both issues useing my old tbi iac
is this normal

the tpi unit and harness/ecm came from a 91 formula auto and my car is a 91 rs

ill be it the car is much stronger then when it had tbi as in much faster 1/4
but why is it that the car is very fast out of the hole but at freeway speeds it seems down on power
i raced a freind that has 04 v6 mustang out of the hole i can have him by a few langths but on the freeway from 70 we are about even with him pulling a bit till around 120 i seem to pull away at that point

is that just the nature of tpi or is something up with my car

formula_novice

iTrader: (1)

You always want to make sure the TPS sensor is adjusted correctly!

See this article for the procedure...

https://www.thirdgen.org/tpimod2

Azrael91966669

that really was kinda what i was thinking the maf tpis are adjustible but speed densitys are not but still have to be set correctly

i was going to post as a reply to another thread but hit the wrong button so i figured id ask a few qwestions

the thread i was reading said speed density ecm dont care where the base voltage is it just starts with what ever its at and counts how high it gose

i had assumed it needed to be set at a correct voltage for idle

to low it hunts to high its revving and out of idle mode

i also had a very hard time setting min idle did the procedure 8 or 9 times
it would work for 1 start after but the 2nd start it wouldnt hold an idle just stall

then i decided to try useing my tbis iac and just set it tell it would idle and would do the "whooop" noise when giving it full throttle from a stop

also what port should the fuel pressuer reg be hooked to the larger or smaller port? dose it matter?
i know one small one gose to the hvac

Fast355

iTrader: (2)

Let me see here, you have the SD ECM and the TBI Peanut cam. There is a mis-match there as ALL 305 TPIs from 1990-1992 had the larger L98 cam in them. If you want more power, you need to upgrade the cam in your 305 to a L98/LT1 grind or an aftermarket grind and pay attention to the exhaust system by replacing it from the head ports back.