98 6 bolt swap issues

[GsSkeeT]

Hello, I am new to the site but have had an interest in DSMs for a while now. I've owned several 1g cars that my uncle and cousin have built. Now I have a 2g with a 6 bolt swap. I purchased it already done and have questions regarding making the car perform better. I've rebuilt the throttle body, replaced the tps sensor and have done a boost leak test. It picks and chooses how it wants to idle, either high (1500 ish) or low (6-750 and rough), but it does not surge at all, stays steady. It has a 95 eprom ecu and the 10k pot mod. The pot mod doesn't seem to affect anything unless I turn it too far and the car dies. It has a 16g turbo from a gvr-4 set at 8psi. It runs great, doesn't buck jump or anything, I'm just frustrated with the idle issue. It has a 2g tb and elbo, but a 1g head and intake manifold. Thanks for looking and any help is appreciated. Once again it's a 98 GS-T with 92 6 bolt engine with wiseco 8.5-1 Pistons and eagle rods, ported 1g head.

 

[toddrs93]

Have you checked the IAC motor? Older style ones (brown housing) are junk and fail frequently. newer style (black housing) are usually fine. Theres a simple resistance test to check them, the plunger could be getting stuck.

 

[synthetek]

Check the throttle cable make sure its not to tight. Do you have the FIAV deleted?

 

[GsSkeeT]

I have not deleted the fiav valve. I live in Virginia, would it affect it bad in the winter? It's my daily driver. I replaced the shaft seals and the fiav gasket and the tb gaskets to manifold. I also replaced the biss because the old one was leaking very bad. I did read somewhere to disconnect the iac plug to set the biss if you don't have a special tool. I was told the iac was replaced but it is brown. The throttle cable isn't too tight but the head piece that inserts in the tb mechanism is a little bent/twisted. I made sure the throttle plate closes all the way and adjusted the throttle stop just enough to keep it from sticking closed. The past few days it's been fairly stable unless I turn on the defrost, then it sits at 1500 rpm

 

[GsSkeeT]

Have you checked the IAC motor? Older style ones (brown housing) are junk and fail frequently. newer style (black housing) are usually fine. Theres a simple resistance test to check them, the plunger could be getting stuck.

I live about 30 minutes from you. Are you open on Saturday? If so please pm me the name/address. I'd like for someone to check it out but don't trust too many shops these days

 

[spyderdrifter]

How long has the issue been happening? Has it happened the entire time you've owned the car? Have you researched the proper ways to have the 6 bolt swap done for a full swap compared to a partial swap (such as my spyder which I did a 6 bolt block with 2G head)? Have you inspected the CAS as it can cause idles fluctuations?

 

[GsSkeeT]

How long has the issue been happening? Has it happened the entire time you've owned the car? Have you researched the proper ways to have the 6 bolt swap done for a full swap compared to a partial swap (such as my spyder which I did a 6 bolt block with 2G head)? Have you inspected the CAS as it can cause idles fluctuations?

I've owned the car for a month and a half. When I first got it, it would idle around 2,200 rpm. The throttle body biss and shaft seals were completely shot. I rebuilt the tb and it's been much better. It's a 92 6bolt block, 1g head, 2g tb and elbow, 95ecu w/ 10k pot mod. The car runs flawless under acceleration. It's only the idle I'm having issues with.

 

[The Last AWD TSI]

Did you ever get to the bottom of your idle problem?

 

[GsSkeeT]

Yes I did, thanks for checking. It was the throttle body shaft seals and biss screw oring

 

[Tiki2777]

Yes I did, thanks for checking. It was the throttle body shaft seals and biss screw oring

Do yourself a favor now and ditch that potentiometer while you're at it, tuning is almost impossible with it cutting into the maf readings