89 formula TPI

since i've owned my bird from time to time it will surge/hesitate for a few seconds. to describe the feeling, it's as if i am taking my foot on and off the gas rapidly. it only does it when accelerating from a stop and after the engine's warm

i have read this could be EGR valve, i know it has a tinyyy leak when i tested it last time i was under there by depresing it and holding my finger over the opening. any thoughts?

it's a 5 spd, but i know i am not missing the shift because it does it after it's already in gear. also, fuel pressure is fine, and fuel pump is new

any help/ideas are appreciated!

Tuned Performance

iTrader: (92)

Ohm The injectors when the engine is warm sounds like the engine is running lean. It could be a bad spot on the tps you can do a slow voltage sweep to catch that.

89 formula TPI

could you explain how to ohm injectors and how to do a voltage sweep on the TPS?

sry, don't have much experience w/ a multi meter

rdhanded2

iTrader: (3)

This ^^^^ Also check your coolant temp sensor and timing.

rdhanded2

iTrader: (3)

Ohm injectors:


Check TPS: https://www.thirdgen.org/forums/tpi/...o-i-check.html

89 formula TPI

thanks for the vid!
the fuel injectors are brand new but i will still give this a try since it seems so easy. any other ideas tho? i have a feeling its not this, only because they're new injectors. also, i just timed the car a couple weeks ago.

rdhanded2

iTrader: (3)

Coolant temp sensor. Tps.

dwillis

iTrader: (6)

trust me dude it doesn't matter..I've worked on mine doing basically the same thing for quite a while now to finally find out it was the icm in the "new" distributor I installed after a rebuild..was actually the 2nd "new" dizzy I installed..I guess third times a charm for me.heres a link to my thread on here that I really think will help ya bro.BtW mine is a tpi 5-speed 305 also...Good luck man

dwillis

iTrader: (6)

forgot to post link so here it is
https://www.thirdgen.org/forums/tpi/...el-issues.html

89 formula TPI

too funny, i am on my third dizzy too! couldnt believe the second i bought went so quickly so i was throwing parts at other things for a while.

i will ohm the injectors today and try a TPS sweep test. would like to swap out the EGR as well

coolant temp sensor is new, but cheap enough that it can't hurt to buy another and just swap it out. will keep you guys posted!!

thanks for all the help!

89 formula TPI

so i ohmed the injectors while cold, it read 14.7 across the board.

i am trying to test the TPS but i have an autoranging voltmeter and cant tell if it's reading correctly, i suspect it may be faulty. here is what i am doing:

-set to DC Volts
-turn the key to one click before it starts, so i hear the fuel pump prime
-red lead into the middle hole of the TPS, ground the black
-the meter should read .54, but its jump all over from 1 to 100
-when i try opening and closing the throttle, no effect on reading, still jumping all over
-the OHM setting worked fine for the injectors, and it read okay for the battery, 12.1V but it took a while to eventually settle down to 12.1

not sure if my sensor is actually broker or my meter just sucks!

rdhanded2

iTrader: (3)

The surging is a plague of these cars, and so many different things can cause it that it can drive you crazy. Good luck to you.

johndinu

the conclusion of this? what was the cuprit?
thx