ST185 with an ST205 WRC Swap, A few concerns

fastrax203

New member
I recently picked up a 1990 Alltrac with an ST205 WRC swap installed. The car runs great for the most part but I have a few things that concern me. Some info on the car first, the engine was installed prior to me getting it and they used the ST205 wiring harness and fuse box. For the most part the install is well done. The wiring could be a bit cleaner but it doesn't have any strange voltage draws or CELs that are from faulty wiring. The only CEL I get is a Code 42 (Vehicle Speed Sensor) which is strange as the speedo works.

One concern I have is that the car hesitates when cold. Not bad but when I'm using constant pressure on the throttle (about 30%) in 2nd gear starting around 1500rpm I can feel the engine sorta hesitate until around 3000rpm. Sorta feels like it can't quite figure out where to set the ignition timing. The car has an aftermarket temp sensor installed so the stock gauge doesn't work. Once the car gets to around 140deg F the hesitation goes away. This is where my second concern comes in.

Lag. The car has an extreme sort of boost lag. The previous owner thought it might be a worn out/bad wastegate so he had it replaced with a Kinugawa adjustable one. I don't think this fixed the problem. In 5th gear cruising around 60mph if I roll into the throttle I won't get more than 4psi. If I floor it in 2nd I can get around 6psi. I'm guessing I've got a pretty bad boost leak. I'm going to build a boost leak tester this weekend when I have time to try and pinpoint where the leak could be. Could this also be related to my previous problem with hesitation?

Another question I have is once I have the previous problems sorted what kind of boost is the stock ST185 fuel pump capable of handling with the ST205s 540cc injectors? I plan to install a larger pump in the future but I'm actually enjoying the car as it is but would like to figure out the few character building things this car has haha.

Oh, I almost forgot the interior lights and hazards don't work. The turn signal works just fine but the hazard won't engage. The sunroof doesn't move either. I thought I could hear the relay or motor "click" when I hit the switch but the panel doesn't move. Anyway, any light you guys could shine on my issues would be great! Thanks!
 

Aaron

Member
I'm fairly certain Code 42 refers to a specific VSS sensor in the transmission that informs the ECU of your speed. It is unrelated to the functionality of your speedo. It's been a while so I'm not 100% on the specifics, but you should definitely at least check into it.
 

quieter

Member
did you try using Seafoam to remove carbon buildup? that may be your hesitation on cold starts. did you install an aftermarket radio? maybe the ground or something similar is the culprit for why your lights arent working.
 
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