Engine dying at full throttle

[94.5stroker]

I've got a 2001 f250 with my 7.3 out of my 94 running 238/100 s369 for drag racing. Last week I took it out to test it for drags this last weekend and when I did a four wheel drive launch it launched and died then started back up and went. I figured cps so I pulled the codes and had a cps code. So I swapped in a used one I had lying around and took one out of a spare engine I have with me to the track and it did the same thing with both sensors but no longer throws a cps code. Tonight I messed with all the wiring trying to get it to shut off but can't. So I'm wondering what is causing it to die when I launch. It does it in 2wd or 4wd as long as it's full throttle. Only other codes I'm getting are output speed sensor on tranny and vehicle speed sensor. I had the oss code before and swapped sensors with no luck and finally fixed a wire I thought was bad and it went away. Could either of those codes cause it to shut off? Most times it dies right after the launch and comes right back on but all the gauge lights (least wts i noticed) comes on like you shut the key off, but a couple times I had to restart it with the key. I didn't pull the pcm out but I could feel the chip through the hole i drilled in the cover for the wire and it feels tight, I taped it in with gorrilla tape when I put it in. Only other thing I did before we went to test was my gf was asking me what the switch was for my hydra and I showed her how it works and even put it in no stsrt which I had never done before. Could the no start setting on the hydra be causing me trouble?

 

[94.5stroker]

Anybody got any ideas? I was wondering if it could be the ignition switch since it turns the was light on, but I can't find anything wrong with it even tried banging on it with my pliers and wiggling it to try to get it to shut off but didn't get it to.

 

[Magnum PD]

Only does it at higher boost levels?

 

[David N]

Sounds like its defueling or something. But I have Matt's tunes and haven't ran a boost fooler in years and mine runs great. Or maybe you're running out of HPO. Have you ran a scanner to see what ICP is doing under WOT?

 

[94.5stroker]

Only time I've gotten it to do it is full throttle usually 4wd boost launch but it has done it in 2wd but floored. I don't think it's only boost related cause I can push 45 pounds of boost through it when it doesn't die.

I haven't watched the gauge when it dies but it usually runs 2800-3000 on my gauge in cab. It completely shuts off the pickup I even had to restart it with the key twice, idk what it does when it defauels but I assumed it would just loose power not die completely. I have a boost fooled.

 

[superpsd]

Going to be a fun one to diagnose. I've had issues like this due to loose harness connectors or broken wires in which the heavy instant inertia opened the circuit and shut everything down. Beyond that I would possibly look at HPO and data log a few things if you can like ICP and IPR. Double check all pigtails like the CPS and IPR pigtails. If you loose HPO the engine will shutdown and or CPS. Also make sure you don't have some odd electrical issue going on. If the PCM sees less than 10V it will shutdown. Not likely but I threw it out there. Other shorted sensors I believe have been know to shutdown the PCM. However inertia is causing your issue so I would suspect loose connections or hot wire rubbing to ground somewhere. Or HPO issue under instant demand. What CPS are you using? My suspicion is you still have a CPS circuit issue but curious. To see what you find.

 

[Plzstrokeme]

I'm sure you probably have e fuel but the fuel bowl heater could cause this issue if its still installed.

 

[94.5stroker]

I'm with you on the inertia cause whenever I've had just a bad cps it would do it randomly and although I don't drive this pickup much other than racing or playing I did take it 40 miles or so round trip and it never did it until I went full throttle. The cps is a used one i pulled out of one of my spare motors, both of them i tried were used. I can't imagine they were both bad and both would do the exact same thing only at full throttle but who knows. I was planning on hooking up my laptop and seeing what icp and ipr are doing, but whether Icp is falling off or something else is shutting it off it's still gonna show 0 icp once it dies so idk if that will tell me anything.

Fuel bowl is gone.

I wonder if the chip could be causing me troubles, maybe it's loose or the contacts aren't cleaned well enough. But I find that hard to believe cause I got this thing put together in march and drove it a bunch including a lot of launches and never had this problem until last week. I will pull the chip out and go see what it does, least eliminate that.

 

[boggerr]

Does it only die when doing a boosted launch?

 

[mandkole]

Shutting off like a switch only on a stationary launch seems definitely electrical (especially if you can roll in and get to max load without dying). As said will take some troubleshooting, wire moving while its running, etc--good news is that its running about where it should. Keep us posted.

 

[boggerr]

If it's just on launch it could be the TC locking and stalling it out. Did that with my 7.3 a few times.
I would look into those codes you have. I have seen the wires going to the trans sensors messed up right at the plug more times than I can count. Grab the wire in your finger tips about an inch away from the plug and give it a pull. Either it will be good or you will start stretching the wire which means it's broke inside the insulation

 

[Arisley]

One other thing to check. Is part of your intake, between the filter and the turbo, made out of rubber? I have seen those collapse under huge load, but when eased up to speed and power, they don't collapse.

 

[94.5stroker]

Didn't think about tc locking up I can log the two shift solenoids and the tc lockup see what it's doing. I had both of those codes before thought i fixed them when I found a broken wire.

Only thing that has me wondering is it turns the gauge dummy lights on when it does it and I don't ever remember cps doing that. I just kinda wonder if it's in the key switch. It's an old farm pickup I picked up cheap and when I first got it some times when you shut the key off and pulled it out it would leave the radio on. But then it quit doing it so I didn't worry about it. And even now it has run start and a place to pull the key out, but no acc. Every ford I've ever had had acc when you turn it all the way back. Thinking bout Just throwing a new ignition switch in it just cause it's prolly pretty cheap and fast to try.

 

[94.5stroker]

Missed yours arisley the intake tube is stainless

 

[boggerr]

My 08 and I think my 2000 the key turned forward for acc.
Did the radio shut off when you opened the door with the key out?

Arisley has a good point. Is there any rubber boots on the intake?
All the dummy lights could be coming on cause it drops so low in RPMs that the PCM thinks it stalled

 

[94.5stroker]

I swapped ignition switches with a parts pickup of mine forgot it had one. Did three 4wd launches first two it never died third one I blew apart a powersterring hose trying to hold the brakes under boost. Got another hose coming tonight then I'll try it a couple more times if it don't do it I'm taking it to the track tomorrow.

 

[94.5stroker]

Well I took it to the track last night with the different ignition switch, made eight passes and it never died once. I'm thinking that was the problem. Looks like 13.2 is as much as I'm gonna squeeze out of this set up. I'm a lil bummed cause I really wanted to break into that 12 second range. Thinking bout putting a small kit of nos in to see if I can get it down there. 60' leaves a lot to be desired at 1.8-1.9, but I ran out of time trying to get the cal tracs set up. Also don't think the nittos are holding as good as I hoped they would from what I read. But it was also really hot and humid and the track was slick.

 

[sootie]

You've got a least a tenth in the launch alone I would think

 

[94.5stroker]

I definitely need some shocks... looking into some Rancho 9000's and I need to spend some more time messing with my caltracs. Think this set up has 12'.99 in it? Haha I haven't seen any faster than 100.2 out of it

 

[mandkole]

You might get another tenth in the front half with some more tuning/weight loss but I think you're tapped on fuel-- over the last 8 years of my setup, 100-101 is all that my truck has been able to do.