CPS Causing miss

supradjza80

Mr. Formula SAE
Apr 24, 2007
782
0
0
38
Appleton, WI
www.uwracing.com
thevork;1394448 said:
I have that too and am not bothered by it although ofcourse mine is modified in some way (lexriemer) and yours seem to be stockish.

I'd point at the coilpack/wires/ first but hey that's just me.

well, coil packs all ohm fine, wires ohm fine and are NGK's bought last fall. Plugs were changed at the same time to Denso Iridiums, so tried new NGK coppers, same problem with .028 gap.
 

CajunKenny

PULL MY FINGER. PLEASE!
Nov 15, 2007
3,255
0
0
Washington
An awful lot of supras out there have a slight idle stumble or miss. Mine included. When I first got mine it didn't stumble at all. It idle'd smooth and perfect.

I got a bhg and after repairing that, I got the typical idle stumble/miss. As with yours, mine is fine in all other ways. Power is good, no hiccups under throttle, etc...

My buddy just got a 91T and his idle is perfect! He's stock though.

I don't know man....I wouldn't say that your idle is "normal"; but, I would say that it's typical of our cars. Now if you EVER figure it out, LET ME KNOW!!!! ;)

Nice car by the way. And a 1992 to boot! :)
 

supradjza80

Mr. Formula SAE
Apr 24, 2007
782
0
0
38
Appleton, WI
www.uwracing.com
dumbo;1395152 said:
Did you try the external ignitor ground?

Nope haven't done this yet, I guess I will try that next. It seems to be a common consensus that the CPS could not be the cause just due to higher than normal resistance so I have to keep trying things.

CajunKenny said:
An awful lot of supras out there have a slight idle stumble or miss. Mine included. When I first got mine it didn't stumble at all. It idle'd smooth and perfect.

I got a bhg and after repairing that, I got the typical idle stumble/miss. As with yours, mine is fine in all other ways. Power is good, no hiccups under throttle, etc...

My buddy just got a 91T and his idle is perfect! He's stock though.

I don't know man....I wouldn't say that your idle is "normal"; but, I would say that it's typical of our cars. Now if you EVER figure it out, LET ME KNOW!!!!

Nice car by the way. And a 1992 to boot!

Well we have something slightly in common here. When I first got my car and all last year (about 10,000 miles put on the car last summer while slowly upgrading it and doing basic maintenance) The car had a perfectly smooth idle.

Then I stored it all winter and a few days after I took it out the Water outlet gasket where it meets the head started leaking really bad (took it apart and one of the bolts was missing and the gasket had shifted. To do this I had to take out the CPS. I put everything back together and right away after that I it began missing (before I timed it even). This lead me to beleive after checking so many different things that it was caused from the CPS since I had messed with it just prior to the miss beginning. And when I tested the Resistance and saw it out of spec I thought I had my answer, but who knows. Anyway the car has idled with the miss ever since.

I will try the igniter ground trick to see if that fixes it but I'm not holding my breath.

And thanks for the kind words on the car, I have been pretty lucky so far with it, and I'm pretty happy its a 92, although I would have been happy with any clean 89+:naughty:
 

CajunKenny

PULL MY FINGER. PLEASE!
Nov 15, 2007
3,255
0
0
Washington
The igniter ground mod is definitely worth your time. Even if it doesn't fix the idle, it's a preventative thing. It's something I plan on doing this winter myself.

I am also going to completely rebuild one of my spare CPS's this winter. I plan on doing the whole thing, including all wires.
 

slightly_red_MA70

Holy S*** I own a Racecar
Jan 24, 2009
417
0
0
Canada
Im having the same problem with my N/A. It has a miss that makes the car backfire every once in a while when im idling. I checked my plugs and they were massively gummed up with carbon residue. Would this be related to supradjza80's problem but his being CPS and mine distributor??
 

CajunKenny

PULL MY FINGER. PLEASE!
Nov 15, 2007
3,255
0
0
Washington
redma70;1395573 said:
I checked my plugs and they were massively gummed up with carbon residue. Would this be related to supradjza80's problem but his being CPS and mine distributor??

Nope he changed out his plugs. :)
 

TurboStreetCar

Formerly Nosechunks
Feb 25, 2006
2,776
3
38
Long Island, Ny
3p141592654;1390593 said:
Looks like the pickups were replaced and the CPS rebuilt, or its nearly brand new.

Did you get measurements for the gaps? Also, is the top reluctor flush with the top of the G1/G2 pickups?

Any place to source new pickups? im going to be rebuilding my CPS because of the oil leak and the wires are so hammered the insulation cracks if you move them.

I would LOVE to put new coils into this thing, especially because im going standalone and i want as many new sensors as possible.