Scrubos
Probationary Member
- 14
- 2
- Feb 11, 2018
-
Marshfield,
Missouri
Hello, title pretty much sums up my situation.
Just purchased this mostly stock 90 Talon TSI awd, this is my first turbo car, so it's all a little new to me, but I rebuilt my 4g37 1ga, for what that's worth.
Long story short, I've gone down the list confirming everything mechanical. Fixed all boost leaks, including TB shaft seals, set throttle stop, confirmed TPS working, etc. It idles great, but the problem I'm chasing is a quick blip of the throttle makes the motor bog down for a full second or so before it adjusts and recovers. A slow crack of the throttle hides the issue and it has no other signs that anything is wrong, EXCEPT the CEL will illunate for half a second under boost (or it might just be kind of random, it doesn't do it consistently, but always under load).
So, having chased my tail long enough, I hooked up a bulb to pin 1 and 12 in the diag port, and... Nothing. Confirmed 12 has ground, confirmed no short between 1 and 10. Finally pulled the ECU and was pleasantly surprised to find a reman from 03 with good caps and a virgin EPROM, BUT no hat flippin connection between diag port and pin 1, and more importantly the wire for pin 2 at the ECU is completely gone. It's not hanging in the wire loom at all. Furthermore, I noticed the wire for pin 1 at the ECU is yellow with a red stripe instead of solid yellow like at the plug.
is going on here?
It's definitely a 90 motor, or at least a 90 throttle body.
I'm about to just run new wires, but don't know if I've got an oddball car (even more oddball than 90s in general), or I've someone just ape f***ed the wiring when they rebuilt the ECU. Maybe it had a socketed ECU at one point? I don't know.
Why on earth would someone remove pin 2 wire from the ECU and then just leave it? Can't be...
The car hasn't been abused per say, but the previous owner seemed to think an EVO 3 16g turbo was a good idea, but then never followed up with supporting mods. What I understand from reading other posts, this won't hurt the car, (he claims he drove it for about a year like this), but is ultimately kinda dumb without supporting mods as you aren't actually making more boost, it just takes longer to spool.
Can anyone confirm or deny? Is this accurate? Or has this motor potentially been suffering by leaning out in the high boost/high rpm?
Final thought, I was cracking the throttle under the hood the other day, and noticed that during the second of hang where the engine is bogged down, I can hear something happening up front, either turbo area, or possibly just coming from the air intake tube. It sounds like something getting sucked closed. To describe it, you blip the throttle and the rpms fall as you hear a faint sucking sound, almost like a quiet woosh of air, quickly followed by a little thud like the sound of something sealing shut real quick.
Is that the wastegate sticking open at idle? This is where my complete lack of experience with turbo cars shines, because I don't see how that would be possible with the spring pressure able to hold it closed under boost, but I have no idea if this even abnormal.
Any help there is appreciated, obviously I'm more concerned with my pinout issue right now.
Just purchased this mostly stock 90 Talon TSI awd, this is my first turbo car, so it's all a little new to me, but I rebuilt my 4g37 1ga, for what that's worth.
Long story short, I've gone down the list confirming everything mechanical. Fixed all boost leaks, including TB shaft seals, set throttle stop, confirmed TPS working, etc. It idles great, but the problem I'm chasing is a quick blip of the throttle makes the motor bog down for a full second or so before it adjusts and recovers. A slow crack of the throttle hides the issue and it has no other signs that anything is wrong, EXCEPT the CEL will illunate for half a second under boost (or it might just be kind of random, it doesn't do it consistently, but always under load).
So, having chased my tail long enough, I hooked up a bulb to pin 1 and 12 in the diag port, and... Nothing. Confirmed 12 has ground, confirmed no short between 1 and 10. Finally pulled the ECU and was pleasantly surprised to find a reman from 03 with good caps and a virgin EPROM, BUT no hat flippin connection between diag port and pin 1, and more importantly the wire for pin 2 at the ECU is completely gone. It's not hanging in the wire loom at all. Furthermore, I noticed the wire for pin 1 at the ECU is yellow with a red stripe instead of solid yellow like at the plug.
is going on here? It's definitely a 90 motor, or at least a 90 throttle body.
I'm about to just run new wires, but don't know if I've got an oddball car (even more oddball than 90s in general), or I've someone just ape f***ed the wiring when they rebuilt the ECU. Maybe it had a socketed ECU at one point? I don't know.
Why on earth would someone remove pin 2 wire from the ECU and then just leave it? Can't be...
The car hasn't been abused per say, but the previous owner seemed to think an EVO 3 16g turbo was a good idea, but then never followed up with supporting mods. What I understand from reading other posts, this won't hurt the car, (he claims he drove it for about a year like this), but is ultimately kinda dumb without supporting mods as you aren't actually making more boost, it just takes longer to spool.
Can anyone confirm or deny? Is this accurate? Or has this motor potentially been suffering by leaning out in the high boost/high rpm?
Final thought, I was cracking the throttle under the hood the other day, and noticed that during the second of hang where the engine is bogged down, I can hear something happening up front, either turbo area, or possibly just coming from the air intake tube. It sounds like something getting sucked closed. To describe it, you blip the throttle and the rpms fall as you hear a faint sucking sound, almost like a quiet woosh of air, quickly followed by a little thud like the sound of something sealing shut real quick.
Is that the wastegate sticking open at idle? This is where my complete lack of experience with turbo cars shines, because I don't see how that would be possible with the spring pressure able to hold it closed under boost, but I have no idea if this even abnormal.
Any help there is appreciated, obviously I'm more concerned with my pinout issue right now.
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