Don - i thought that the RAD was for top end defueling.... not for mid range. I have had a couple people drive my truck that have had experiance with the defuel and said mine was the worst they had ever seen!!

 

Im not certain, but I think the truck will defuel at launch and even up at the top end. The top end might be from speed limit, but that is also dealt with using a RAD.

You WILL have to own a RAD if you plan on drag racing!!

Don~

 

I don't know if that the RAD will be the only fix on defueling like it was last year. I hear that the new blue chip box and the MAD ECM both defeat defueling.

There are several things that maybe causing SD's defuel issue. The thing I don't understand is being able to rev 2000 rpm's with the brakes on, this alone maybe confusing the ECM. When driving locked up does it still do the defueling?

 

Marco said on some trucks it does, and some trucks it does not. Verdict is still out ...to quote him

 

opie - yes even in lockup i can feel it defuel.....although it is not as pronounced. I drove a buddys DTT equiped truck yesterday that is set up fairly comperable power wise to mine, just without the twins. The converter started moving the truck at 1250-1300 r's under mild throttle. I did have to rev it to almost 2 grand to get the tires loose. I didnt feel any defuel in his. I am having another converter made that is tighter. I am also getting a MAD ECM. I dont want to wait for it to get here however, and i dont want to have to buy a RAD if it wont work. Any idea of someone that has one i can try for a hour and see if it cures my problems?

 

Eric, I have not forgotten about you Man. Im just swamped up to my eyeballs. I have your sticks on the bench and I am getting closer!!

Sorry for the delay,

Don~

 

Good to hear from you Eric, I heard about that both ways too I hope that mine is one of the trucks that the MADD works on.

SD I have the 93 torq converter I haven't tried the 89 which is probably the one you tested. But you have ruled out another possibility. Do you have access to someone that will lend you some smaller tires to check that theory out?

 

do you think 35's would be enough of a difference in size? I do have a set of those i can put on.

 

I don't know, I haven't delt with or heard of your exact problem before if you where in the hood I would let you use mine...

 

opie - you have a rad dont you?

 

i put my 35's on tonight and i dont like what happened. The defueling became more pronounced. i think with the engine revving faster due to the smaller and MUCH lighter tire, i am hitting my defuel spots faster and easier. I think it might be time for a p-pump.......

 

SD I do have a RAD. And it would probably stop your problem at the cost of not having a tach indication. There is definately something wrong and using the RAD to cover it up isn't the right answer, not yet anyway.lol

You have done a huge mod on your truck, during the mod did you have any problems with of the injection pump, EDM, APPS, Comp or associated wiring to them? Have you double checked all your connections if so the next thing I would try would be to completely unhook the Comp, hook up all the connections back to factory, disconnect the batteries, turn the ign key to start a couple times, rehook the batteries, recal the APPS and go out for a spin again.

 

This is going to sound dumb, but when you did the manual to auto swap, did you change the apps assy, the manual truck, and the auto's are different.

 

cd- yes the apps were changed between the 2 trucks

opie- the truck is just fine in every regard other then the defuel (well i actually have a few tranny bugs, but thats another story) I have tried taking it back to stock, (no comp) and it still does it, just less pronounced.

 

So now when are you taking the truck in to hook up the odbIII? I have my original IP that I keep around for a backup, I can send it to you to trouble shoot with if you want.

Also what is the gear ratio in your truck and what was it in the donor truck?