omaharam

Ok
I've dynoed at 502hp with turbo, Hot Juice, and mp-8.
I've dynoed at 547 by adding Diablosport Predator.
The truck has always pulled hard clear through redline.

So I went to pick up my truck yesterday after having 90hp DDP tips installed and we threw it on the dyno. It maxed out at 460hp at 2200rpm. We tried different combos of boxes and settings and got the same results every time. It had a good strong power curve up until 2200 rpm and then just flatlined. We pulled the pressure box off and made a run with the Juice on 5 and the Diablosport on performance. This should have pulled the rail pressure down quite a bit with no pressure box. Instead, the pressure climbed just like normal. That means that the ECM is pulling the pulse duration away from the injectors. The question is why. No electronics have changed. The only thing changed was a mechanical part - the injectors. The ecm shouldn't even know they are different from stock. But every pull - I think we did around 10 - at 2200 rpm the power curve just went dead straight accross to redline.

Any thoughts?

TORQUE BEAST

new injectors take a little while to loosen up. I had the same problem on our tractors. The longer we ran it, the more hp it had.

Totallyrad

My first thought would be that you were draining the rail but..... I'm not up on all the stuff out there and how to put it together but, before you did the injectors you had adequate air for the fuel supplied by the injectors. Now that you've added more fuel, you may have to add more air. Also, I saw something Don M from F1 posted that went against everything that people accept as the gospel. I believe he stated that larger injectors actually retard the timing. Up to that point, I'd always seen people post that bigger sticks advanced the timing. I'd have to do allot of backtracking to find it but I think I quoted him correctly. Maybe all you need is a little more advance.

cquestad

I hate to have to question the injectors...

What did your rail gauge show as actual pressure?
Did the smoke clear up?

morkable

One thing I would try is to clear out all programmers from the ecm, take all boxes off. Then unhook the batteries, after they are BOTH unhooked, touch the positive and negative cables together on the drivers side battery (not sure if it would make a difference as to which side) This will drain all energy from the ecm. After a couple of minutes of this, rehook up the batteries. Start truck, then put on boxes and programmers,, I think this might fix up your problem.

The ECM's on these trucks have a certain ammount of adative learning capabilities and sometimes they get screwed up so you need to retrain them

Kevin

omaharam

With no pressure box, the rail gauge was about 20k when we started the run. It dropped down to about 15k and then quickly recovered and climbed to about 25k. That was with the 90hp injectors, and a theoretical 250hp worth of timing and duration. My cp3 shouldn't have been able to deep up with those fueling demands. John said it should have fallen to like 9 or 10 and then not really recovered much if any. He believes the reason that it recovered and climbed is because the ecm was pulling all of the pulse duration away from the injectors and then the pump could keep up. I wish I had a picture of the graph to show, but we didn't even bother to print one. It absolute flatlined at 2200rpms.

I wasn't really watching the smoke as I was in the cab with John helping to watch gauges and the drb. If you're thinking the rail relief valve, he checked that. he talked to Lenny at DDP today and has another call out to one of his "secret" sources. The truck is going back down next weekend to hoepfully figure out what's going on.

I guess the other part of this is that on the street the truck feels like it has more than the 460hp the dyno showed. All I have hooked up at the moment is the Hot Juice. I have never driven or even ridden in a truck with injectors before, so it's hard to compare. It even sounds different. I have also been driving a vehicle with a lot less power for the past two weeks.

omaharam

It was mentioned taking the boxes off and then beatin' on it for a couple days, but what is the battery cable thing suppose to do? If there is no power from the batteries, I can't imagine what touching dead cables together could possibly do.

morkable

That will drain the ecm,, the ecm will hold power for a period of time,, so either you can unhook the cables and wait an hour or touch them together and wait 2 minutes

Kevin

dodgezilla04

instead of touching cables, you can turn the key on. that will dump the capacitors too.

cquestad

It has capaciters....

dodgezilla04

yes, but not the flux kind.......

ramtd02

are you batteries supplying the needed 1.21 gigawatts?? Sorry had too.

cquestad

This one is getting good!

dodgezilla04

here i was trying to help someone out, and you guys start turning me into Dr. Emmet Brown

blownsmoke2

Well now I know I'm not the only truck with this problem now. My last dyno on a mustang was 511 and I know the truck pulls alot harder than it did when I had 547 on a dyno jet. I always thought the injectors were hurting me but couldn't prove it as everything was done all at once. But now I've got 4 melted pistons so i'll start all over.