JenSHO1

Hi all
I have a 93 SHO automatic, and...... I'm in love with my car!! I don't want to have to send it away!!!

It has some problems.....

when I start it, it is fine until I step on the gas. If I step on the gas, then take my foot off, it immediately stalls.

The only way I can keep it going is if, when I start the car, I hold the throttle at 900RPMs for like 5 minutes, then I slowly take my foot off the gas to see if it will stay at 900. If it does, then I can go. During the first couple minutes of the trip, the revs go up and down, sometimes down to 500 where it almost stalls.....

HELP!!:)

Johnny Mullet

Try cleaning or replacing the IAC (Idle Air Control) valve.

tbird100636

And the throttle body too. Use carb. cleaner or brake clean. Spray the gunk, get an old tooth brush and scrub the gunk some, then remove it with the cleaner.

JenSHO1

Thanks guys, hey Johnny Mullet, I'm in ohio too.

The mechanic I took it to said that it might be the ERG valve, which he is going to replace in the morning, but he said that he didn't know if that would fix it...he said he doesn't know anything about SHOs, should I have him go ahead and replace the IAC?

Johnny Mullet

The EGR would set off a check engine light if bad. Is it on?

JenSHO1

Intermittently....
He said that the ERG code did come up.... that's why he suggested replacing it, because he said he had no other clue what to do

JenSHO1

I got a call back from the mechanic this morning
He said that only 4 cylinders were firing because "the coil for the last two cylinders is blown"
he said that he cleaned out the egr valve and throttle body, and that it ran a little better after that..... but that he thinks the main problem with the revs is the fact that the cylinders aren't firing

does this sound reasonable to you guys?

SHOZ123

Make sure the coil power plug is inserted fully.

To see if the EGR valve itself is the problem when the engine is idling apply vacuum, watch the stem to see if it moves. This should cause the car to stumble.

More than likely the EGR code was for insufficient flow and that would be the DPFEgr sensor. The EGR is know to coke up the passageways too not allowing enough gas to pass. :) But the valves themselves rarely go bad.

What is the particular code?

bertha66

If the coils are not firing all 6, it would be something like what he is saying. My 93 mtx does not have a EGR valve, it does have a tube system in it's place. I don't know if having a autotrans would be differant or not.

__________________
Allen D
64 Galaxie, 66 F100 4x4, 80 Bronco, 90 Areostar,
68 F350 Crew Truck, 93 SHO 93 MTX,93 SHO ATX

SHOZ123

And if just one coil is bad the tach will read 66% of true engine speed.