i did the tb mod on a spare tb. moved the tps over to the mod tb and installed the tb. now here comes the screwed up stuff. car started up fine. idled ok. when i brought the engine up to 3000 rpm (and kept it there) it started to surge, from about 2k to 3k. so i tried it at different rpm's. i noticed it didnt do it above 3k. so, left it at idle, plugged in a jumper for idle adjustment, got a multimeter and tried to adjusted tps. meter wouldnt ge a reading unless tps was unplugged. adjusted to 1.2 ohms and plugged it back in. and adjusted idle with screw on top of tb to 1200 rpm (lowest it would go), unplugged jumper. still, with any pedal input under 3k, would surge. for some wierd reason i unplugged the tps, everything ran fine. idle at 800 rpm. took it out for a nice drive, stumbled throughout rpm range. came back home, now no idle just dies. so i plugged back in the tps, working fine. HELP plz. any ideas would really help me.

 

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What "mod" did you do?

B

 

http://fc3s-pro.com/TECH/HOWTO/TBM/tbm.html

 

Thats the problem mine had for the longest time. After putting in a rebuild, it woulnd't hold a steady idle. It would always bounce back and forth in the RPM range. Most likely if it doesnt do it when the tps is unplugged, its the TPS causing the problems. Try bringing the idle down to 750 RPM idle using the BAC valve and the TPS. That should clear it up.

 

how do you do it with the BAC

 

probably a big vac leak

 

There is a screw on the BAC valve. It might be covered with a cap, it might not. Turning it to the right lowers idle speed, to the left raises it. You will probly wanna go all the way to the right to start.

 

thanx areexseven.....ill give that a try

 

all right. all the surging stopped. that part is good to go. thanx for all the info on that. now i think i have a new problem. i adjusted the idle to about 900ish rpm using the BAC. idled good until i took it for a healthy drive. after the drive the idle was lower around 600. and when i use the brakes or the lights it drops even lower. did i screw things up by adjusting the idle with the BAC. another question, why would i have to adjust the BAC if it worked fine before. i appreciate any info anyone can give.

t

 

BTW, TPS should be set to 1K after car is fully warmed up. 1.2 Ohm is WAY TOO LOW. I don't think that's even possible.

 

what i meant was 1200

 

Because when you did the TB mod, you removed alot of stuff that effected the idle. The BAC valve was set to a certain point to hold the idle at 750 with those parts. Once removed, that setting doesn't match up.

 

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