1G install 2g tps on 1990

[caldixiechick]

My apologies if this has been answered but I couldn't find it.

The TPS is bad on my 1990. Since the OEM replacement is no longer available, I'm supposed to be able to replace it with a 2g TPS and a wiring adapter that I ordered from STM Tuning. The new TPS arrived and there's a problem. There is a shaft that the new TPS does not allow for.

What is the resolution? I did see where this question was asked before but there was no solution given.

Please see photos illustrating the problem. TIA

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[steve]

Sorry, as you've noted the 90 TPS only fits the 90 TB.
If you put a later '91+ TB on, the '90 Fuel Rail gets in the way, IIRC.

 

[caldixiechick]

Thank you. That's good to know as I was thinking replacing the TB may be the only fix. Or on the off chance I can find a used 90 TPS that still works. What started this search for a replacement is the check engine light is on and the code is a problem with the TPS.

 

[DSMPT]

90 throttle body has different shaft/TPS/ISC, that's why many 90 owners swap with 91-94 throttle body because it's easy to find parts.

You may be able to find a used 90 TPS easily if you make a wanted post here or in DSM related facebook groups. I'm sure some 90 owners still have it and they are willing to sell it.

To use a 2G TPS, your throttle body needs be 91-94 or 2g. But as @steve mentioned above that it will interfere with fuel rail inlet flange on a 90 (if my memory serves me well, you can install it by rotating the TPS 180 degree).

And to use a 91-94 throttle body on a 90, it would also require some wire work since TPS/ISC plugs are different.

 

[enriquez2000]

I actually might have one in my shed

 

[caldixiechick]

Thank you everyone. I was able to find a 90 TPS from a seller on marketplace that I recently purchased another item from. Hopefully, this will fix it for a while, clear the check engine light and solve the cold start problem so I can drive the thing. The long term plan is to source a 91-94 TB and a fuel rail if needed to have ready to go when this now 30 year old part fails. The wiring adapter that I ordered I'll keep since who knows how long that item will remain available.

My goal with this car is to keep it mostly stock with some modest improvements, something fun to jet around town and save miles on my truck. Aside from the immediate problems above, the usual oil leaks and a tired motor, it's in great shape for it's age. This forum is such a great resource. Know that those of you who take the time to post is very much appreciated.

 

[enriquez2000]

You will 100 percent need a fuel rail when you swap. My friend killed my perfectly good tps on my 93 throttle body when we put things back together.