I got the j tube back yesterday and tonight installed the 90mm tb. The truck wont' run.

It tries to start... chugs or performs one short Vroooomm ... and then just dies. Tried it about 20 times I guess with the same results and sometimes got a light "Reduced Engine Power".

So.. here I am with no help within 200 miles and I need some suggestions.

Need new tune?

 

did you test the TB before install? as in before bolting anything up, plugging everything in, turning key to accessory, and pressing the gas pedal to verify the butterfly is moving appropriately?

 

Didn't know I could and never thought of it. So you are suggesting I take the intake tube off and turn the key to accessory? (counterclockwise)... or to power but not activate the starter or maybe turn it over and see if the tb works?

 

didnt realize our trucks ignition turn cc. Anyway, essentially yes, turn the key to the last position before you would start the engine and have someone verify the butterfly is opening when you press the gas pedal.

 

And if it doesn't what do you suggest? I'm thinkin remove the tb, the harness I got from Speartech and the pcm and sent it all to ????? to get checked out. Who would the ???? be ? Speartech???? Or????

 

couple of possibilities

1. incorrect harness for application
2. incorrect harness and TAC module for application

Fixes:

1. Get a new harness made
2. Get new harness/TAC module verify volt ref signal

 

I appreciate your help but that doesn't tell me anything to do.

I can check the connections to see if they are tight and that's about it. Other than that I can remove everything and send it to somebody to have it made to work.

I don't know what a TAC is and I sure as hell don't know what it means to veryify the volt ref signal. I know NOTHING about computers or electrical systems. I mean NOTHING. So I'm completely helpless. Sad but true. Maybe pathetic, that's sure as hell how it feels. But regardless of how pathetic it is that still is the reality of the situation.

I've been up since 4:30am and it's almost 9pm here now and I'm beat. I'm not going back to the garage tonight anyway. I 'll check the tb to see if it works in the morining and if it does not I"ll call Speartech and ask for some help.

 

From the looks of things you have an early DBW set up, I think there might be some differences in your set up from others. Have you veryfied that the harness was the right one for your application? You will need to check into the TAC signal, there is a possiblity that you will need to change the TAC module along with your TB (as stated in several other threads) I dont think you can just change the TB on the truck, it is a package dea.

 

John at Speartech was aware that my dbw setup was different from the rest and sent a special harness he made up for this specific system. My stock tb had two plugs and he sent me a harness with correct connecters to plug into both of those plugs and then into the new tb.

I don't know what I have to say to get across that I don't have the ability to check the TAC signal. I don't have any idea what a TAC is or what a TAC module is.

I know it's hard for you to imagine that I'm as totally ignorant of this as I am. I say it again.... I have no idea what a TAC or a TAC module is... or what to change or how to change it or where to look to find it.

I don't have any memory of any reference to changing any thing but the tb and the j tube and getting the harness from Speartech. IF any mention was made in any thread about changing a TAC module (whatever that is) then I did not catch that reference at all. Edit: I just checked the original thread that you and moregrip put up and sure enough you mention that the correct TAC module has to be obtained.

Ok. Now what?? Where is the TAC?? What one do I get? Where do I get it? How is it changed? Thanks, Jim

 

good luck jim...all i have is moral support wish i could help ya....