Check Engine Light at WOT

[tbrown1986]

Yesterday while coming home from Brians Truck Shop in Lead Hill, Arkansas my check engine light came on. I had just left Brians shop after he installed my new transmission. I was pulling a 30ft tandem axel gooseneck trailer with duals with my buddies 08 F250 loaded on it. For anyone who's not been to Lead Hill, its exactly that, very hilly! I was accelerating towards the first hill, it was blowing smoke then the check engine light came on. When I got to the top of the hill it was running rough just like it was missing. I turned it off and restarted it. The check engine light was off and we started home again. The next hill it did exactly the same thing.

I've got Full Force stage ones, TS 6 Position with BTS tunes..now, exhaust and a home made intake. Am I running out of oil because of my stock HPOP? Whats the deal? This problem

 

[ToMang07]

My guess is a weak HPOP, "Low ICP" code. I'd check it. Mine will do it if I hold WOT for more than a couple seconds. Comes on, let off throttle, goes off a minute or so later.

 

[Rideracelivemx7]

that's exactly what that sounds like, if your running stage 1s try a T500 pump. cheap and super effective, youll like it

 

[Russ]

agreed hpop

 

[tbrown1986]

My guess is a weak HPOP, "Low ICP" code. I'd check it. Mine will do it if I hold WOT for more than a couple seconds. Comes on, let off throttle, goes off a minute or so later.

Here is the deal. I went to BTS to have a transmission rebuilt. He put it in, went for a test drive. All of this is with Brian riding shotgun..... The shift from 1 to 2 was so hard it would bang your head against the headrest. He asked me what tunes I had and I said Wildman tunes purchased from Complete Performance in Jasper, TX. I'd never had trouble with my chip before and was very happy with the increased performance. We rode back to the shop. Brian told me that Wildman's tunes increase line pressure and that's what it was. He convinced me to let me reburn my chip with his tunes on there. I agreed. He burnt my chip, reinstalled it, and we took off again. It was doing the exact same thing... hard 1-2 shift while the rest of the shifts were smooth as silk. We took it back, he scratched it head for a minute and said he would remove the valve body and adjust it. He did and when he reinstalled it all again we went for a another ride.

This time 1-2 was a lot better and I was happy. My point is that with the Wildman tunes the light would only come on if I held WOT for 5 or more seconds. When I let go and came to idle it idled just fine with no miss. The light stayed on but it wasn't missing. Now the light stays on and it runs like a 2 Stroke Detroit.

 

[tbrown1986]

If its the HPOP why before when I had Wildman tunes the light would come on but not miss. Now the light comes on and it runs like Sh*t. I got mad last night and drove the 160 miles with the light on and it missing.

Come to find out it was a problem with the valve body and my tunes were fine. Brian said the Wildman tunes were increasing the line pressure and that's what was causing the hard 1-2 shift but come to find out it was the valve body...

 

[ToMang07]

This time 1-2 was a lot better and I was happy. My point is that with the Wildman tunes the light would only come on if I held WOT for 5 or more seconds. When I let go and came to idle it idled just fine with no miss. The light stayed on but it wasn't missing. Now the light stays on and it runs like a 2 Stroke Detroit.

Well this sounds very different from your original post.... could you describe how it's running better? Misfiring? One bank not working?

I would talk to Brian some more if it's a tuning problem. Either way, really.

So the light doesn't go off at all anymore?

Time to locate a good scanner, like AE, Snap-On, etc

 

[tbrown1986]

The transmission is fine now. Brian adjusted the valve body. Brian told me that my tunes were what was causing the transmission to shift hard from 1-2. Brian redid my chip with his tunes. The chip was reinstalled and we took another drive. The transmission, with his tunes, was still shifting hard from 1-2. We got back to his shop. He redid the valve body. Reinstalled it and took another test drive. The transmission shifts great now.

Now my problem is that at Wide Open Throttle the check engine light comes on and stays on. The truck also starts missing. If I shut the engine off and restart it the engine light goes away and the truck idles correctly. As soon as I get on WOT again the same problem occurs... check engine light, rough idle.....

Before Brian put his tunes on my chip I would get the same engine light at WOT. The light would stay on but it wouldn't miss. So with Wildman the light was on but it WAS NOT missing. With Brians tunes I have a check engine light and it misses.

Hopefully that clears up the confusion. I never was a very good story teller!!!!

 

[old man dave]

Brian's tunes may be more aggressive in HPO demand causing loss of HPO pressure near peak oil demand.

 

[OldschoolPSD]

Did you pull the codes? Low ICP code wont cause it to run funny afterwards, but an overboost code will.

I'll go ahead and nip this one in the bud (because I'm sure some keyboard mechanic is going to say otherwise) by saying that an OBS WILL throw overboost codes.
I have had this issue with my truck and witnessed it with others. It will give you a CEL and then run rough until you shut the truck down and restart it.

 

[tbrown1986]

I put a code reader on it last night. The reader said it didn't have any codes stored. I cleared all the codes, even though it wasn't showing any, and I'm going to try it today. I think I might have my chip sent back to Tony to have his tunes put back on.

Everytime the check engine light comes on that's means its throwing a code right? When it throws a code it should store that code until you clear it out..right? I was using a Snap-on reader btw...

 

[ToMang07]

I put a code reader on it last night. The reader said it didn't have any codes stored. I cleared all the codes, even though it wasn't showing any, and I'm going to try it today. I think I might have my chip sent back to Tony to have his tunes put back on.

Everytime the check engine light comes on that's means its throwing a code right? When it throws a code it should store that code until you clear it out..right? I was using a Snap-on reader btw...

Weird...if the light was on there IS a code present. What model scanner is it?

 

[old man dave]

Did you pull the codes? Low ICP code wont cause it to run funny afterwards, but an overboost code will.

I'll go ahead and nip this one in the bud (because I'm sure some keyboard mechanic is going to say otherwise) by saying that an OBS WILL throw overboost codes.
I have had this issue with my truck and witnessed it with others. It will give you a CEL and then run rough until you shut the truck down and restart it.

I guess I'm a keyboard mechanic then since my '97 California (MME-7) will throw a p0238 temporarily and then a permanent one after several temporary ones. Just a code and did not run better or worse with a stored p0238. Boost fooler cured CEL and code. MME-x PCM strategy is different than any of the Federal ones. If it was running worse with a stored p0238 then I have to wonder just how much more it would make than the 408hp@32psi that it did?

 

[dieselmandustin]

I used to have this same issue at wot with the check engine light and it also would run rough like you are saying. Of course this was back in the superchip days many moons ago. a boost fooler fixed that issue for me. I would start with getting a boost fooler. Its fairly inexpensive. Hope you get it straightened out bud. Good luck!

 

[fordfreak4life]

I still haven't figured out why you were dragging a trailer at wot

Sent while spinning 18 wheels

 

[DIESEL SHOP LLC.]

Did you pull the codes? Low ICP code wont cause it to run funny afterwards, but an overboost code will.

I'll go ahead and nip this one in the bud (because I'm sure some keyboard mechanic is going to say otherwise) by saying that an OBS WILL throw overboost codes.
I have had this issue with my truck and witnessed it with others. It will give you a CEL and then run rough until you shut the truck down and restart it.

The obs are funny like that some throw a overboost code some don't, but sounds like hpop or overboost codes for sure.

 

[DIESEL SHOP LLC.]

I still haven't figured out why you were dragging a trailer at wot

Sent while spinning 18 wheels

very true.!!

 

[OldschoolPSD]

I guess I'm a keyboard mechanic then since my '97 California (MME-7) will throw a p0238 temporarily and then a permanent one after several temporary ones. Just a code and did not run better or worse with a stored p0238. Boost fooler cured CEL and code. MME-x PCM strategy is different than any of the Federal ones. If it was running worse with a stored p0238 then I have to wonder just how much more it would make than the 408hp@32psi that it did?

So what do you want, a cookie?

 

[old man dave]

Sounds like you're a pretty bad a$$ keyboard mechanic:shocked: putting out some bad info.

 

[OldschoolPSD]

What info was that?