HELP! Many problems with unknown causes

[fartman]

Hi, all. Hope I can get lots of input from you guys.

My 90 5spd turbo is giving me problems with boost and idle. So far, it has a new rebuilt (reconditioned) engine put in, a recirculated HKS SSQV, Magnaflow CAT, and Tanabe SMH. But I don't think that these could be the cause of the problems. I made sure there were no leaks with intake. Before the engine was put in, it had no idle problems, but did have a problem with boost. When approaching 2500rpm, and going uphill, it did the complete opposite of what the turbo should be doing. Instead of going faster, it bogged big time. Since the car had 220k miles on it, and the previous owner did not know much about the car, I thought an engine change would be good. Well, after an engine change, getting the BOV installed, and the rack-and-pinion replaced, this morning, the car bogged again! This time, it is whenever I go beyond 2000rpm. I hear the turbo whining, but nothing on the end of acceleration, just deceleration.

Also, I had this car go to numerous shops. I reside in Livermore, CA, and had the car go to some shops in the area. But nobody knows much on the car. To the NorCal guys, do you guys know a good shop that really knows how to work on this car? I do as much as I can by myself, but the heavy stuff is something I can't do. Any help is appreciated.

 

[Poodles]

Is it showing boost on the gauge?

Sounds like the symptoms of a slipping clutch to me...

 

[grimreaper]

my bad afm connector caused HORRIBLE bogging as well in the 2000-3000 range at part throttle. it would go then stop on its own. how ever i soon threw a code after it started doing that. any codes?

 

[fartman]

Is it showing boost on the gauge?

Sounds like the symptoms of a slipping clutch to me...

It isn't really, but I don't know if the gauge is busted. The oil gauge doesn't work, and neither does the trip meter. But then, it could also be the oil pressure and turbo pressure sensors themselves, huh?

 

[fartman]

my bad afm connector caused HORRIBLE bogging as well in the 2000-3000 range at part throttle. it would go then stop on its own. how ever i soon threw a code after it started doing that. any codes?

Haven't checked for codes. How would I go about doing that?

 

[teedoff00]

This should help you out! You could have easily found it by searching, but the link is easier i suppose.
http://www.cygnusx1.net/Supra/TechTips/engine_error_codes.aspx
Good Luck!

 

[fartman]

This should help you out! You could have easily found it by searching, but the link is easier i suppose.
http://www.cygnusx1.net/Supra/TechTips/engine_error_codes.aspx
Good Luck!

Thanks! I never knew that. I always thought you had to have a special electronic tool to plug into the diagnostic, and then it would display the code. I don't have time to check rite now, but I'll keep this updated after I get a chance tomorrow (hopefully...).

 

[ForcedTorque]

Sounds also like signs of a boost leak.

 

[fartman]

I did a little more research here. I noticed some oil in the intercooler pipe, which could mean that the turbo is going out. Do you think I have a dead turbo?

 

[enjoi.this]

I believe it is normal to have some oil in your intercooler lines. Unless you have a catch can installed then you could eliminate the oil in pipes. Correct me if im wrong...

 

[fartman]

UPDATE: I checked the error codes, and received 12 (RPM signal), 14 (Ignition signal), and 52 (Knock sensor signal). I highly assume that it is the knock sensor wiring that could be causing this problem. What do we think? From what one of my previous mechanics told me, he replaced 'a' knock sensor, which could mean he didn't replace the other. But researching on this forum more, most of the problems involve the wiring for it, and not the actual sensor. Since it causes the ECU to retard the timing, could this be the reason why the engine would run like crap whenever I go above 2000rpm? Also, does someone have a picture of where the 2 knock sensors are located? Can't seem to find it off of the TSRM. I checked my hard copy TSRM as well (yes, I have the actual TSRM) and could not find which section it was in. Thanks in advance, everybody.

 

[Rennat]

fartman - PM me sometime and i'll come out to help work on your car. i live just over the altamont in tracy!!!

 

[fartman]

fartman - PM me sometime and i'll come out to help work on your car. i live just over the altamont in tracy!!!

Thanks for the consideration! Technically, I shouldn't even be working on my car. My apartment complex doesn't allow it...

 

[jdub]

A code 52 will make you car run with reduced power output, but it won't cause what you described.

I'll give you a hint - the TCCS Fail-Safe for IGf failure (code 14) is fuel injection is stopped

 

[fartman]

A code 52 will make you car run with reduced power output, but it won't cause what you described.

I'll give you a hint - the TCCS Fail-Safe for IGf failure (code 14) is fuel injection is stopped

I'm a little bit confused about 'fuel injection is stopped'. Mechanic said he replaced something with the ignition, but I was confused on what he was talking about too. He said something about 'distributor' but I told him that it is a distributorless system, but he said that there still is one, and he replaced that one. What in the ignition system should I check then? Do you think that it is the igniter?

UPDATE: I start the engine, and it runs like nothing ever happened, but I highly assume that this problem will occur again.

 

[jdub]

1st - You don't have a "distributor" - you have a Cam Position Sensor (CPS).
If he replaced it (a very expensive part), the code 12 should have gone away unless wiring was the issue. The RPM input to the ECU is generated by the Ne and G1/G2 pick-ups in the CPS.

2nd - "Fuel injection is stopped" means exactly that...the IGf signal is required for the motor to run. When a coil fires it sends a signal to the igniter which then sends the IGf signal to the ECU. If the engine still runs with this code, think about what the most likely culprit is

3rd - Code 52 is most likely due to the KS wiring.

Codes 52 and 12 are compounding the main problem...code 14.

Pull the EFI fuse in the engine bay fuse block for a minute and put it back. Run the car again and check codes to see what pops up. The codes you show now may be left over from when you had the car worked on previously.

I think I'd get a new mechanic if I were you.

 

[92TealSupra]

1st - You don't have a "distributor" - you have a Cam Position Sensor (CPS).
If he replaced it (a very expensive part), the code 12 should have gone away unless wiring was the issue. The RPM input to the ECU is generated by the Ne and G1/G2 pick-ups in the CPS.

2nd - "Fuel injection is stopped" means exactly that...the IGf signal is required for the motor to run. When a coil fires it sends a signal to the igniter which then sends the IGf signal to the ECU. If the engine still runs with this code, think about what the most likely culprit is

3rd - Code 52 is most likely due to the KS wiring.

Codes 52 and 12 are compounding the main problem...code 14.

Pull the EFI fuse in the engine bay fuse block for a minute and put it back. Run the car again and check codes to see what pops up. The codes you show now may be left over from when you had the car worked on previously.

I think I'd get a new mechanic if I were you.

As jDub said new mechanic would be my 1st step towards repairs

 

[fartman]

Hell yes, gentlemen! I'm already tired of him. I had a great mechanic once, but he closed his shop. I always went to him for work on my AE86. So far, no good ones after him. Which is why I ask, does anyone know of any good mechanics in NorCal San Francisco area, except for yourselves :icon_bigg?

 

[jdub]

Do this:

Pull the EFI fuse in the engine bay fuse block for a minute and put it back. Run the car again and check codes to see what pops up. The codes you show now may be left over from when you had the car worked on previously.

I beginning to suspect you have wiring issues (i.e. old, brittle wiring) from the igniter to the coils and from the CPS through it's connector (and perhaps the CPS wires over the front of the motor). You may also have a bad coil.

Lets see what codes there are after you clear them per above.

 

[fartman]

Do this:



I beginning to suspect you have wiring issues (i.e. old, brittle wiring) from the igniter to the coils and from the CPS through it's connector (and perhaps the CPS wires over the front of the motor). You may also have a bad coil.

Lets see what codes there are after you clear them per above.

I cleared the codes, and then checked the codes. It is continuously blinking, meaning that there is nothing 'wrong'. So I took it for a spin, revved to 3000-3500rpm before each shift, only hitting 4th gear though, and it drove like it should normally. But it was like this before. When I drove it from Fresno to Livermore, which is about 120 miles away, it didn't give me any problems, unless I had the A/C on, which hella sucked power. But two days after that, I tried driving it to work, and it gives me the problems I listed when I first started the thread. Does anyone else find this weird?? If anyone has had this happen to them, tell me your story.

Hey jdub, since you're a motor oil expert, can you answer me this question? I live in Northern California, and I prefer using Mobil 1 oil for my vehicles. Which grade should I use for this engine?