1987 turbo 5-speed
Pretty much stock:
-Cone filter
-Upper hard pipe with knock off blow-off valve to atmosphere
-3 inch exhaust turbo back no cats
-12 gal fuel cell with external fuel pump and filter (probably an ebay kit)
All mods were done by the previous owner, I've just been fixing his mistakes.
A couple problems with my car at the moment:
The MAIN problem:
1) So after finally getting my car running and driving, I'm having some trouble with a code 31.
It idles fine, with a slight miss every so often. Pulls -18 vacuum at idle. Running very rich, just installed new plugs a couple weeks ago and they're already covered in carbon. (Barely ever drive it)
Every so often when I'm driving, the CEL will come on and stay on. The engine will run a little rough, then the CEL will turn off and all is back to normal. It has done this at an idle too, but only after driving it; It was a rough idle and eventually died. It had no power at all. No lights, no cranking. I removed the + cable off the battery and put it back on, and I got it to start.
When driving, I can accelerate fine, but once I hit a certain RPM, it's like I hit fuel cut. No CEL and no stored code from this. Tach doesn't work, so I'm not sure what RPM; but I'd guess roughly 4000 RPM. It happens whether I'm in vacuum or boost. Roughly -3 vacuum or +4 boost.
I just replaced the AFM around when I replaced the plugs. With the old afm, the idle would rev up and down and barely stay alive. If I tapped the gas, it would die. With this AFM I don't have those symptoms.
Checked it out with a multimeter:
THA-E2: good per TSRM (I think 1750 Ohms at roughly 75 degrees)
VC-E1: 4.99V
Then I tried to check frequency..
KS-E1: 23Hz, at first. After a second or two it jumped up to 35Hz, then 45, then 60,80,95,130,80.. Couldn't get a good reading. The most constant it stayed was 45Hz though.
I tested the KS wire for continuity and it checked out, but I ran a new wire anyways. No surprise, it didn't change much.
I'm guessing the RPM problem and the code 31 are related, and the ECU is in fail safe mode. That would explain the running rich situation too. Although I can go WOT and it'll accelerate until that certain RPM without a problem.
With the way the AFM frequency checked out, I guess it could be another faulty AFM though.
2) Tach doesn't work. All the wiring has continuity. Tach used to bounce when cranking, but the engine never started. Replaced the coil packs and igniter, car started but the tach stopped bouncing. Tried putting the old igniter on, didn't make a difference. Ordered a new tach, will try to replace it and see if that's the problem.
EDIT: Fixed the tach. I'm an idiot. When I had the original igniter, I re-pinned the tach wire to the blank spot next to it. When I switched igniters, I hadn't moved the harness side pin back. Swapped it back and it works fine.
A couple other problems I need to resolve, just not my highest priority.
3)Interior lights don't work. This includes: dome, footwells, glovebox, door open warning, courtesy, key ring, door key cylinder, rear hatch, cig lighter lights. The 20A Dome fuse is fine, I've tried multiple fuses and tested with a multimeter. I know the rear hatch, door key cylinder, courtesy, and door open warning lights used to work. The dome lights would work if I wiggled them. Now none of them work at all, possibly integration relay 1?
4)Weird bell-ringing noise from transmission. Metal on metal sound, increases with speed. Usually occurs at lower speeds and goes away at cruising speed. If I'm rolling with the clutch in, out of gear, and put pressure like I'm going to put it in gear, it goes away.
Pretty much stock:
-Cone filter
-Upper hard pipe with knock off blow-off valve to atmosphere
-3 inch exhaust turbo back no cats
-12 gal fuel cell with external fuel pump and filter (probably an ebay kit)
All mods were done by the previous owner, I've just been fixing his mistakes.
A couple problems with my car at the moment:
The MAIN problem:
1) So after finally getting my car running and driving, I'm having some trouble with a code 31.
It idles fine, with a slight miss every so often. Pulls -18 vacuum at idle. Running very rich, just installed new plugs a couple weeks ago and they're already covered in carbon. (Barely ever drive it)
Every so often when I'm driving, the CEL will come on and stay on. The engine will run a little rough, then the CEL will turn off and all is back to normal. It has done this at an idle too, but only after driving it; It was a rough idle and eventually died. It had no power at all. No lights, no cranking. I removed the + cable off the battery and put it back on, and I got it to start.
When driving, I can accelerate fine, but once I hit a certain RPM, it's like I hit fuel cut. No CEL and no stored code from this. Tach doesn't work, so I'm not sure what RPM; but I'd guess roughly 4000 RPM. It happens whether I'm in vacuum or boost. Roughly -3 vacuum or +4 boost.
I just replaced the AFM around when I replaced the plugs. With the old afm, the idle would rev up and down and barely stay alive. If I tapped the gas, it would die. With this AFM I don't have those symptoms.
Checked it out with a multimeter:
THA-E2: good per TSRM (I think 1750 Ohms at roughly 75 degrees)
VC-E1: 4.99V
Then I tried to check frequency..
KS-E1: 23Hz, at first. After a second or two it jumped up to 35Hz, then 45, then 60,80,95,130,80.. Couldn't get a good reading. The most constant it stayed was 45Hz though.
I tested the KS wire for continuity and it checked out, but I ran a new wire anyways. No surprise, it didn't change much.
I'm guessing the RPM problem and the code 31 are related, and the ECU is in fail safe mode. That would explain the running rich situation too. Although I can go WOT and it'll accelerate until that certain RPM without a problem.
With the way the AFM frequency checked out, I guess it could be another faulty AFM though.
2) Tach doesn't work. All the wiring has continuity. Tach used to bounce when cranking, but the engine never started. Replaced the coil packs and igniter, car started but the tach stopped bouncing. Tried putting the old igniter on, didn't make a difference. Ordered a new tach, will try to replace it and see if that's the problem.
EDIT: Fixed the tach. I'm an idiot. When I had the original igniter, I re-pinned the tach wire to the blank spot next to it. When I switched igniters, I hadn't moved the harness side pin back. Swapped it back and it works fine.
A couple other problems I need to resolve, just not my highest priority.
3)Interior lights don't work. This includes: dome, footwells, glovebox, door open warning, courtesy, key ring, door key cylinder, rear hatch, cig lighter lights. The 20A Dome fuse is fine, I've tried multiple fuses and tested with a multimeter. I know the rear hatch, door key cylinder, courtesy, and door open warning lights used to work. The dome lights would work if I wiggled them. Now none of them work at all, possibly integration relay 1?
4)Weird bell-ringing noise from transmission. Metal on metal sound, increases with speed. Usually occurs at lower speeds and goes away at cruising speed. If I'm rolling with the clutch in, out of gear, and put pressure like I'm going to put it in gear, it goes away.
Last edited:
