bad idle strange "electrical sound"

[akujiki87]

hey guys, got a 1g 90 gst, when i bought it it would sometimes randomly stall at idle, i figured because BOV was vented. i recirculated it and same issue. so i thought ICS, so i did the 91-94 throttle body swap, didnt adjust my TPS to the propper ohms, it reads about .812 as it sets, so i had a higher idle. but now the odd part is my car has started idling lower again but rough, was holding around 1500=2k, now drops to 1k and under but studders.

Then my battery went. So i jumped the car yesterday, listened and i could hear what almost sounded like sparking when you have the wire off, but fainter. So i swapped plugs and wires and its still there, and i can smell a slight burning smell, not the kind of burning oil makes but more plastic or electrical, can anyone give me any tips to where to look? thank you!

 

[Scoobystyl]

Id say you have a really bad ISC that burnt up the drivers in the ecu and its causing the mpi relay to click, my friend just went through this and burnt up 2 ecus before figuring it out. check your ecu.

 

[akujiki87]

ok question, is the ISC the part on the bottom of the throttle body that tends to go out, or is it the small switch on the top with the single fuse like plug? if its the one on the bottom i checked it the other day with a multimeter and it checked good.

 

[Scoobystyl]

Yes its the one you checked then with the square 6 pin connector, id still pull the ecu its a 5 min job and then you can narrow it down

Im guessing it looks something like the pictures i have in the my post at the bottom of the page
http://www.dsmtuners.com/forums/dsm-build-journals/442013-co-saving-95-tsi-high-hp-build.html

 

[iwillnotbleed]

Sounds like your ISC is going crazy trying to adjust your air coming in. Where did you smell the burning? Inside the car or in the engine bay?

 

[akujiki87]

i smell the burning under the hood, and hear that sound as well. ill pull the ecu to look at it, ive been meaning to yank it to see if its eprom or not as well. would the ecu still function propper if it looked like that? when i drive the car it drives fine, just gives the issues at idle

 

[iwillnotbleed]

Yeah, check the ECU just to make sure it's not leaking and it looks good. It sounds more like you're getting too much air at idle. Make sure you're CAS is adjusted properly (correct timing). Could also be something as simple as needing to replace the BISS o-ring or the BISS just being screwed out too far.

 

[akujiki87]

the biss is actually almost screwed all the way in this damn throttle body swap has been a PIA

 

[iwillnotbleed]

Hmm.. I know this is an overly used question on this site, but have you done a boost leak test?

 

[akujiki87]

not yet, i have yet to get the time to make a tester or order one online, been extremely busy with work and overtime i barely have time to check the ecu after work tonight.

 

[iwillnotbleed]

I understand the work thing. Another thing you could do if you can't get a hold of a BLT is to use a vacuum hose. Just a foot or two. Turn the car on, put one end of the hose real close to your ear and run the other end around where there could be a leak. Wont help too much with small leaks but if it's all you've got at the time, it works. Keep updating when you get a chance to test all this stuff.

 

[akujiki87]

I can hear a nice hiss when the motor is running around the throttle area but I'm almost thinking its the intake mani gasket itself? I do know vacuum lines are disconnected and plugged.

 

[iwillnotbleed]

As long as the ports are plugged it should be ok.One place that could be overlooked is on the underside of the throttle body in between the manifold and throttle body. When I started tinkering with my car I figured out, after much cursing, the gasket between the TB and Mani had to be positioned and rotated in a certain way when putting everything back. If it wasn't that certain way, it let a reasonable amount of air through.

 

[akujiki87]

I'll Deff check that today. I havnt pulled ecu yet but I did notice when I had it idling last night's it would idle around 1k pretty steady, then it would make a click almost like a spark and then idle lower and rough then get back to 1k smoother.