sesshona

hi this is my first posting, so please be gentle! i've also
searched for solutions for quite a while.

anyways, my car is a bone stock '91 n/a fc and here are my problems:

1. when it starts it dies immediately. if i give it some gas for a few seconds, it will hold an idle.
2. there is a severe hesitation when giving it gas. its through the entire rpm range and the car will shake a lot.

i have not checked the bac yet, but i have adjusted the tps to spec and have checked the resistence of the coils (1.6 ohm) and cas. new spark plugs, battery and air/ fuel filters. there are no vaccum leaks either.

the compression is 90psi in the front rotor and 95psi in the rear rotor.

thanks for the help!!! need to get this running or it's getting parted

hIGGI

iTrader: (7)

hows timing?

sesshona

timing has been set for the leading coil, but when the light was hooked up to the trailing coil, there was no signal. when i checked for arcing, there was plenty of spark available.

could fuel delivery be a problem?

91_fc

yeah. i think its possible. maybe clogged injectors or a dirty fuel filter? hmm..

sesshona

the fuel filter was changed, so i guess i should get the injectors cleaned...

DR_Toast

iTrader: (1)

are the sparkplugs in the right order?

sesshona

yeah, the trailing on top and leading on bottom. wires are pluged in correctly as well.

sesshona

originally the leading plugs were both on the front rotor and trailing on the rear rotor. the previous owner did this, but installing new plugs in the right slots didn't do a whole lot.

Kim

Im not sure but check if the AirFlowMeter(AFM) plug is loose or disconnected

sesshona

nope, it's plugged in.

jacobcartmill

iTrader: (6)

did this problem happen out of nowhere?

this REALLY sounds like an AFM problem as Kim said. go check the voltage AT THE ECU for the AFM signal and see what it reads while you have the car running, (you may have ot have a friend help you with that since the car wont idle on its own)

sesshona

thanks, i'll check that tomorrow. the problem sorta happened after leaving the car in storage while i was out of the county for a month...

i also gutted the precat since it was melted, but left the main cat alone since it still appeared fine.

RETed

Dying trying to idle is a good indication that there's an intake vacuum leak somewhere - a good sized one.

Hesitation?  Dunno - not without more info.
Does it do it all the time?
At a certain RPM?
When the engine is cold?
When the engine is warm?
Does it change as the engine warms up?
Is it just an isolated spot or just gets worse the higher the revs?


-Ted

sesshona

well it only dies at startup. if i give it some gas for like 15 seconds, i will stay alive for as long as i leave it on.

"Hesitation?"
Yes, the car shakes and bucks. when i give it gas, it feels worse.
"Does it do it all the time?"
Yes
"At a certain RPM?"
At all rpms.
"When the engine is cold?"
Yes.
"When the engine is warm?"
Yes, but not as bad.
"Does it change as the engine warms up?"
above.
"Is it just an isolated spot or just gets worse the higher the revs?"
its actually worse at lower rpms, when it gets higher it smooths out a bit.

sorry if my explainations don't help too much><

sesshona

ok, i checked the afm itself and it works fine, the resistance is also good.

with the car running like jacobcartmill said, the voltage on the ecu was 14V for the AirFlow meter when its suppost to read at 2-3V. could this be the problem?

the fuel injectors were 13V (3W, 3Y) and 14V (3X, 3Z) and a few other things read as 14V that are suppost to be 12V.

I also retested the tps and it reads as 6.5k at WOT.

thanks very much for the help guys!

RETed

Have you tried scanning for error codes off the ECU?
It sure sounds like it's running in limp home mode.
Cross your fingers it's not an code #27.


-Ted

sesshona

yeah i tried looking for codes when this first happened, but nothing comes up! could my computer or the self-diagnosis thing be toast?

RETed

With the key in the ON position, and you ground out the coupler, the ENGINE check light should stay on for 3 seconds before it goes out.&nbsp; If you don't see the light go on for the initial 3 seconds, there is something wrong with the ECU or the wiring.&nbsp; The 3 second light is it's own self-check function.


-Ted

sesshona

the check engine light does come on for 3 seconds when i put the key in. could the ecu be bad if the voltage is off on the ecu itself for many of the systems?

sesshona

ecu toast?

sesshona

bump

sesshona

bump

nerid25

here's a bump just for you

rxhaven7

definantly try a new tps cause my car did the hesitation thing and i got a new tps and it runs strong now

sesshona

thanks for the bump. i guess i'll try to get a working tps.