I have an Ef sedan (91) with a OBD1 LS in it. it runs great except for one unsolvable problem, i cant put the gas pedal to the floor. when i give it gas, it takes off then as soon as I hit the floor it bogs down and the RPMS just woooooo go down, until 1500 when the car starts shaking and bouncing off of 1500.

has anyone encountered this, or knows what it might be? (I have no check engine codes showing)

 

vac. leak.. that or crank position sensor.. maybe both

 

Sounds like your map sensor maybe messed up? Are you throwing any codes? Is everything converted to obd1 I assume? Which ECU are you running?

 

LS computer 0bd1 P75 i believe

yes its converted, i had the wiring done by someone i later found out was a little incapable, but with the no check engine code, i feel its gotta be mechanical.

to the vac leak comment, would tht happen only at full throttle??

 

Does the "check engine light" even work? You would know by when you first turn the key on, it will light up briefly. Did the car ever run properly with the swap? Some people forget to repin the tps wiring when they go from dpfi to mpfi, you might want to check that, just throwing out some ideas.

 

TPS, check to make sure its wired right

 

x2 try switching the two outer wires around on the plug take like 30 seconds if that

 

check engine light does work. i had a code for about 6months until the other day i finally solved the problem

i replaced the TPS with a blox one. but elaborate this wire idea, because my code was for IACV and i figured out tht the wrong plug was plugged into it

and the car has run well the whole time with the swap, short of this problem, which ONLY comes up at absolute full throttle, pedal pinned on the floor

 

I would check for a vacuum leak, full throttle would need no leaks to open everything up correctly

 

So. This morning I looked around the TPS for any addition plugs that maybe were over looked and are the correct one. found nothing. so i unplugged the one in the TPS to see if itd throw a code, I figured if it did this, that must be the correct plug, if it was incorrect this whole time its not gonna care if its there or not. well it did, threw code 7 (TPS) so i plugged that back in and tried to address the vac leak idea, but i had no clue how. so google came into play. another forum told me to take the intake off and put my hand over the throttle body, if it stalls no leak if it doesnt...leak. well i did tht (tht hurt pretty nice! lol) since it sucked my hand so hard i decided to try it with my sleeve over my hand, after id say less than 15 secs it stalled out.

So i took it for a ride. and floored it. and no bogging down, just took off. SUCCESS! or so i thought....i turned off my street onto the main road and opened it up just to have bahhhhhh down. It did this same thing yesterday. and the only factor I can see is its been rather chilly here the past 2 days. so ive reached the conclusion that when the engine is ice cold, it doesnt act up. but once it has the 1/2mi drive down my street, back to suck.


I hope this new info helps with anymore ideas. and if anyone has a better way to check for a vac leak or anything else please share.

 

helppp

 

Check your ignition timing (make sure you disable the electronic advance with a jumper before checking/setting).

Do a voltage check on the TPS not just a 'plugged in and not throwing a code' check.