ok guys you all are my last hope! ive searched all forums and even through google im at the end of my rope here. i got a 92 formula 350 sd tpi. it has been converted from auto to t56. problem is i cant get it to idle smooth for long. ive had recnt probs as well i have changed out the knock sensor and the iac sensor. before i replaced the iac i cleaned the old one and adjusted got it to idile fine for a while restarted the car and idile started to flucuiate again. i slapped the new one on same deal.ive also blocked off the egr valve as well. the only other code i have come up with is bad o2. i know its not a vac leak because it idiles for a while then flucs. the car is stock with only a spd polished runners and plenum. please help any opinoins are greatly appreciated thanks im tired good night

 

It sounds to me like the computer is going into closed loop and is getting a bad reading from the o2. Does it run fine cold and bad when it warms up a bit?

-By the way I like the member name you have.

 

I am sure you have addressed this but, If the speed sensor isn't hooked up on the T56 the engine will stall when you come back to idle. I know this is the case on a MAF car because I have had that problem. I believe my problem will be solved shortly with the additon of an Abott box. Do you have your electronic speedometer working correctly with the T56?

 

thanks man i stole it from motley crue and since are our cars are in that era perfect! ok yes i do have a electro speedo i have bought the box yet but iam looking into it. i also replaced the iac with a used one my buddy had it works better but now idiles a little high. going to look into the box and keep you guys posted. i also got o2 code replacing it tomm thanks

 

The product that you need is a Dakota Digital speed odometer calibration unit. I did the conversion to t56 and without the box the inputs from transmission are way to high for the speedo. the dakota digital box down converts those signals for use in the older systems that we have. w/o the box in the system and the vss not hooked up the ecm doesn't know the right idle to set to when the rpms come down. Price for the unit is around $80. The abott box (Cable X) is used for cars where the speedo is mechanical and the transmission is electronic. If this is the product you bought then you need to return that and get this product.

http://www.dakotadigital.com/index.c...rod/prd126.htm

 

thanks alot everyone here is the latest. i orderd the box today for electric speedo, dgi-5 changed the o2 no real differance in that area. i also plugged the lines to the egr sensor the right way. checked all other vaccum lines to the engine and found everything good. checked the map sensor and also found it good. the car still idiles like crap when intially started. also the car idiles high when i drop into neuatral from gear, i tap the idile and it goes to normal. do you guys really think the speedo is causing all of this? has anyone had problems converting from auto to stick on tpi? thanks man

 

I definitely think the speedo is causing your problem with the drop in idle when you go from gear to neutral. I had this problem also b/f I put the Dakota Digital box on the car. I could tap the gas and the idle would smooth out until the next time when the car was in motion again. The box should fix this problem.

 

You may want to start searching for a 5 speed prom mine would not run right until i installed one in my car.

 

ok thanks again everyone im still waiting for the box to come in the mail so i can wire that baby up. as far as the prom goes i need to pick up the piggy back from a freind so i can swap it to stick car. i also tested my map sensor and plugged up more vac lines and there was no change so i will just cross my fingers on the box for the idile. once again i appreciate everyones help and im glad this site is up for us. im on my 4th third gen i just love these cars thanks