NEW to Canada3si...just bought a 92 TT..need help!

Doberman77 · 08-29-14, 11:29 AM

Hi, I bought a '92 R/T Turbo a few weaks ago. I drove it home about 240km. It ran just OK, a bit of a hestitation around 3500rpm, rough hig idle, and a bit of backfiring(lean miss). I knew it needed a tune-up. So I changed the plugs and wires, oil, etc....all the normal "tune-up" stuff. I even changed the caps on the ECU. It ran 10x better than when I drove it home but, it still idled way to high and had a pretty good hestitation mid rpm's under load. I then fixed a tonne of vacuum leaks, adjusted the TPS and BISS which were WAY outa wack. It seemed like after all the leaks were fixed up, it ran way too rich...it'll barely pull it self down the road now! But it idles ok at around 750rpm. I also installed a new fuel pump and filter, front bank o2 sensor(the only code it spit out for like 5 minutes), and IAC. The speedo bounces a bit below 20mph(its an American car) and once and a while "skips" at other speeds. The ECU has since stored a vehicle speed sensor code but no CEL. I'm not sure the VSS would cause these sort of issues though.

I'm totally stumped and I've worked on cars all my life. I'm starting to get really frustrated!! The car is in great shape otherwise, rebuilt t-case, new driveshafts, brakes...I WANT TO DRIVE IT but I cant even get it E-tested!! PLEASE HELP>>>is it some other sensor?? the ECU?? a turbo issue?? CRIPES!!

rez604 · 08-29-14, 10:28 PM

that was a bit hard to follow, what symptoms are you having now?

what plugs did you use? what gap?
what wires?
are you running stock boost?
what are your fuel trims sitting at?
what gas are you using?
did you verify your tps&iac with a logger?
you're sure your ecu is good?

Doberman77 · 08-30-14, 06:05 AM

Quote:

Originally Posted by rez604

that was a bit hard to follow, what symptoms are you having now?

what plugs did you use? what gap?
what wires?
are you running stock boost?
what are your fuel trims sitting at?
what gas are you using?
did you verify your tps&iac with a logger?
you're sure your ecu is good?

Sorry....the plugs are NGK double platinum I believe, OEM wires, stock everything, no mods, only HKS SBOV, 93 octane gas. I don't have a logger...I checked the TPS A's per the shop manual, and the IAC is brand new. As for the ECU...I guess I'm not 100% sure it's ok...the board showed no signs of damage. I had my father change the caps...he has a lot of experience repairing electronic boards on machinery.
It files fine now, but has absolutely no power when you go to drive/accelerate. It will barely pull itself down the road. Pulled out one of the plugs...it was all black and fuelly. It's like it needed all those leaks to lean itself out to run before!

Doberman77 · 08-30-14, 06:04 PM

Ok, I think I've got one of its issues sorted out...it sure didn't like that HKS BOV! I put the stock one back one and it seems to run way better. Still rough acceleration under heavy throttle and some backfiring though.

95teetee · 08-30-14, 07:25 PM

Quote:

Originally Posted by Doberman77

Ok, I think I've got one of its issues sorted out...it sure didn't like that HKS BOV! I put the stock one back one and it seems to run way better. Still rough acceleration under heavy throttle and some backfiring though.

I was wondering if it could be a case of an externally venting BOV (or lack of, I don't know much about those things lol) causing issues- good to see you're on the right track.

2501 · 08-31-14, 03:12 PM

A few things can cause what you are dealing with. I had the same issues.
I would check the following:
-ignition coils and make sure they are not rotting
-boost leaks
-MAS sensor (difficult to test but at leaks make sure the honeycomb is not damaged or shifted.)

O_ROD · 09-01-14, 12:52 PM

The stuttering on accel sounds like a defective MAS. Try and find someone local and borrow their's to test it out... A logger will be your savior with these cars!

BlackStealth · 09-04-14, 06:54 AM

When an O2 sensor goes bad, it reports low, the ECU responds by richening the AFR mixture. A quick fix to a bad O2 sensor is to unplug both O2 sensors, and unplug the battery for a couple seconds to reset the ECU fuel trims back to 100%. With the O2 sensors unplugged, the ECU will eventually report bad O2 sensors (since they're unplugged), but the car will be much more driveable until you find the time to replace the O2 sensor(s).

Also if you want a device that monitors ECU parameters in real time, see here:

http://www.3si.org/forum/f4/lcdbc-de...onitor-639073/

I also accept payment in Canadian dollar equivalent.

08-29-14, 11:29 AM	#1
Doberman77 Registered User Trader Rating: (0) Join Date: Aug 2014 Location: Sarnia area Posts: 4	NEW to Canada3si...just bought a 92 TT..need help! Hi, I bought a '92 R/T Turbo a few weaks ago. I drove it home about 240km. It ran just OK, a bit of a hestitation around 3500rpm, rough hig idle, and a bit of backfiring(lean miss). I knew it needed a tune-up. So I changed the plugs and wires, oil, etc....all the normal "tune-up" stuff. I even changed the caps on the ECU. It ran 10x better than when I drove it home but, it still idled way to high and had a pretty good hestitation mid rpm's under load. I then fixed a tonne of vacuum leaks, adjusted the TPS and BISS which were WAY outa wack. It seemed like after all the leaks were fixed up, it ran way too rich...it'll barely pull it self down the road now! But it idles ok at around 750rpm. I also installed a new fuel pump and filter, front bank o2 sensor(the only code it spit out for like 5 minutes), and IAC. The speedo bounces a bit below 20mph(its an American car) and once and a while "skips" at other speeds. The ECU has since stored a vehicle speed sensor code but no CEL. I'm not sure the VSS would cause these sort of issues though. I'm totally stumped and I've worked on cars all my life. I'm starting to get really frustrated!! The car is in great shape otherwise, rebuilt t-case, new driveshafts, brakes...I WANT TO DRIVE IT but I cant even get it E-tested!! PLEASE HELP>>>is it some other sensor?? the ECU?? a turbo issue?? CRIPES!!

08-29-14, 10:28 PM	#2
rez604 Registered User Trader Rating: (0) Join Date: Feb 2008 Location: Ca Posts: 457	that was a bit hard to follow, what symptoms are you having now? what plugs did you use? what gap? what wires? are you running stock boost? what are your fuel trims sitting at? what gas are you using? did you verify your tps&iac with a logger? you're sure your ecu is good? __________________ 9b@13psi / 226awhp / 3750lb / 13.04@103mph 1.9' 15g@18psi / ???awhp / 3500lb / 12.50@115mph 1.9' build thread my visit to pitroadm full vinyl wrapped 3000gt the GTO bible - the JDM differences

08-31-14, 03:12 PM	#6
2501 Registered User Trader Rating: (0) Join Date: Nov 2006 Location: Ottawa, Ontario Posts: 266	A few things can cause what you are dealing with. I had the same issues. I would check the following: -ignition coils and make sure they are not rotting -boost leaks -MAS sensor (difficult to test but at leaks make sure the honeycomb is not damaged or shifted.) __________________ 91 Stealth TT 95 3000GT Pearl Yellow -SOLD

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes	Rate This Thread
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode	Rate This Thread:

08-30-14, 06:04 PM	#4
Doberman77 Registered User Trader Rating: (0) Join Date: Aug 2014 Location: Sarnia area Posts: 4	Ok, I think I've got one of its issues sorted out...it sure didn't like that HKS BOV! I put the stock one back one and it seems to run way better. Still rough acceleration under heavy throttle and some backfiring though.

09-01-14, 12:52 PM	#7
O_ROD Registered User Trader Rating: (0) Join Date: Jun 2007 Location: Cornwall, Ontario Posts: 284	The stuttering on accel sounds like a defective MAS. Try and find someone local and borrow their's to test it out... A logger will be your savior with these cars!

09-04-14, 06:54 AM	#8
BlackStealth Registered User Trader Rating: (5) Join Date: Jun 2003 Location: Leamington, Ontario Posts: 396	When an O2 sensor goes bad, it reports low, the ECU responds by richening the AFR mixture. A quick fix to a bad O2 sensor is to unplug both O2 sensors, and unplug the battery for a couple seconds to reset the ECU fuel trims back to 100%. With the O2 sensors unplugged, the ECU will eventually report bad O2 sensors (since they're unplugged), but the car will be much more driveable until you find the time to replace the O2 sensor(s). Also if you want a device that monitors ECU parameters in real time, see here: http://www.3si.org/forum/f4/lcdbc-de...onitor-639073/ I also accept payment in Canadian dollar equivalent.