[FrostKing]

Just a couple of relatively minor bugs that are starting to get on my nerves. First of all my truck wants to idle at 1800 rpm while at low speeds. If I pop it into neutral while rolling, the engine will actually maintain 1600-2000 rpm bouncing up and down. Cruising around it really pushes and requires a lot more braking effort than I am comfortable with. This seemed to coencide with a 180* stat that I installed (modified for 185*). When at a stop, in gear or park/neutral, the rpm is normal. Would this be the truck trying to warm up further via a fast idle??(not while parked though)

Second issue is related to spraying meth./water on 8 psi boost before the throttle body. The more methanol I use, the more unstable the truck gets.(on a weekly scale) After a run the truck will wildly swing between 11 and 17-20+ AFR. Even after a short burst around town, the same will happen. I'm leaning towards the factory O2 sensors overheating at the track causing the fuel control loss, but this wouldn't be the case around town. And my wideband has never glitched and shows the problem when the engine begins to buck. It gets bad enough where the engine will starve and sputter badly waiting in line and staging at the track (almost stalling). Could this be an issue with blowing methanol through the throttle body, screwing with the TPS? How about pooling of meth. inside the intake? In fact I am getting the same results now with no meth. and 3psi boost.

I disassembled the throttle body tonight and found everything spotless inside drive section. I just can't reason why fuel delivery would almost completely stop for 5-10 seconds after a good blast down the road. This is only coming to a stop, there are no problems during hard acceleration.

Any thoughts are appreciated.

 

[sdogre]

how rich is your AFR while spraying meth, my truck will do the same rough running if while i am sprayin nos the nos runs out and I run rich for a second, I have to reset the computer to get is to run properly again, as for the other problems I cant help you

 

[kenihemi]

The high idle problems sound like tuning issues in the smt-6.

Don't know squat about meth, Hemifever does.

 

[FrostKing]

I don't think the smt-6 can affect the idle speed or throttle position. I just finished running my wastegate reference up to the throttle body after the meth nozzle instead of the compressor outlet. I'm going the test everything out tonight and log as much data as possible.

 

[Canadian Hemi]

Good luck with it hopefully you can get the bugs worked out. Too bad your having problems as your truck seemed to run well while you at the GTG.

 

[kenihemi]

I had an idle problem and it was caused by the tune. Mine was a little different, the idle would jump up and down and sometime stall.

 

[FrostKing]

Was specifically in the tune was causing that? The first row of the fuel map?

 

[hemifever]

Are you using the smt6 to control your meth?

 

[FrostKing]

Yes. I'm using the larger nozzle that came with the kit, the original injection map sent in the unit with the multiplier column set to all 1.00 (MAP column I believe)

Without testing on a dyno, I haven't been able to feel a difference making any changes or switching between 75%meth and 50% meth mixtures.

 

[kenihemi]

Yeah, my tune problems were with the bottom row, 1st 3 or 4 numbers on the fuel map.
I was trying to tune by ltft, but found I needed to push that a little.

Actually, hemifever and srt10kllr told me what to look for.

 

[SRT10KLLR]

quote:Originally posted by FrostKing:
I don't think the smt-6 can affect the idle speed or throttle position. I just finished running my wastegate reference up to the throttle body after the meth nozzle instead of the compressor outlet. I'm going the test everything out tonight and log as much data as possible.

Running the wg reference up front will help spool your turbo up just a tad quicker.

IF your a/f is dead on and you introduce meth which has a different(lower - 6:1 vs 14.7:1) stoich a/f than gasoline then that could be causing some stumbling. Try leaning out the gas when you introduce the meth.

 

[FrostKing]

It only stumbles AFTER a run when I'm putzing around. I've got WOT tuned in no problem. I do know the truck is very rich below 3500RPM, so that is this Friday night's project. I didn't think it would be so hard with this truck to get a 60' quicker than 2.2 seconds! (I'm excited to drop this time as it pulls like a freight train on the top end.) Still hitting over 103 MPH with a slow start.

 

[SRT10KLLR]

Running a rich a/f will cause stumbling issues so check you a/f during decel and part throttle driving. Lean them up a little bit at a time so the pcm can adjust.

If you send me a data log I can help you tune it.

 

[4dhp]

Hope you are getting things figured out... or we will have to see if Sharadon will have a 2-for-1 Canadian motor build week, lol. Keep us posted.

I am also interested in what you did with the wiring on the SMT6 for that P0129, I am still getting it and wondered if you went to the gel connectors rather then the solder.

 

[TheBoss]

Your 60' won't vary much with added hp. That's more to do with the setup of yer truck itself. (i.e. suspension, tires, weight transfer, etc.)