Help!!! Turbo Dragon wont run at full throttle

[gutterball]

Hello
I have a 07 Dragon 700 with a boondocker turbo on it, I run with egt's and an o2 sensor, the turbo is a boondocker racegas setup with the ada and the tunnel dump exhaust, it is running on straight VP111 at 6.5 to 7.5 pounds of boost. the symtoms are as follows: the machine starts great, idles great, at half and 3/4 throttle it seems good, but as soon as you go to full throttle, it runs like crap, coughing and sputerring. At 3/4 throttle under light load the egt's are at about 1150, as soon as you pin it, the egt's drop to between 850 and 950 and it misses badly. O'2 sensor shows an unusually high reading of 18 to 24. This machine has run awsome but this started as an intermittant problem and has gotten worse.

Im scratching my head
thanks in advance

 

[Jkinzer]

when you go to full throttle do you lose boost pressure? sounds similar to mine when i blew a hole in my throttle body boot.

 

[gutterball]

Sorry ran out of space.
Heres we know, I believe it is a stock system failure, as I have removed the turbo from the equation including all associated electronics and it still runs like a turd.
Heres what Ive tried: Checked every electrical plug for continuity,checked exhaust valves for power at solenoid and diaphram function, checked pistons and cylinders, checked all fuel filters including in tank, checked fuel pressure, checked compression.

Took it to the dealer and put it on the computer, it did show some codes, but they were all in history, and nothing showed up when running it while hooked up.

It showed a mag side coil error, a pto side coil error, a stator error, and a crank sensor error, but as I said none of these show up on the track stand.
any input would be greatly appreciated.

 

[gutterball]

JKINZER
Thanks for the reply
the most boost it will build at full throttle is 4.5 lbs and the most rpm it will make is 7500
We replaced that laminated throttle plate once as a preventitive measure, I have visually inspected it and it appears to be good.
I'm thinking its something else as it began as an intermittant problem.
The machine would not run one day, then the next day it would run perfect, and then one day later it ran like this.

 

[KAWGRN]

Fouled a plug been there and done that

 

[tabneil]

What is your fuel pressure reg set to? I have seen this with a Tdragon 800... bumped the fuel pressure up and pulls like a freight train. It Ran fine until the flipper was stabbed wide open and started building boost, bumped the pressure up and the slobbering went away.

 

[mn2mtns]

I had the same thing, put on a new fuel filter and it should run fine. At least remove the old one and try to blow through it with your mouth. If you can't blow through it easily, replace it. I know of others that have had this same problem.

 

[gutterball]

KAWGRN: plugs have been changed at least 3 times sinc i started trouble shooting this issue.

tabneil: Its my understanding this turbo doesnt run an adjustable regulator, fuel pressure is at 58 to 60 lbs and has been tested.

mn2mtns: Fuel filter has been replaced with a new one and checked and rechecked to be sure, also I checked the one in the tank to be sure.

Thanks guys keep'em comming hopefully someone will hit something ive missed, originally I was sure it was fuel supply, but that doesnt explain the low exhaust temps.

 

[subman]

09d8turbo

i think you are to rich on top.????

 

[Scott]

Did you put the fuel fuel filter in backwards?

 

[Jkinzer]

shot in the dark but on mine once the reeds start going bad it actually runs worse full throttle.... most people say that you should notice it low end and while chopping the throttle but on mine it was more noticeable to me on the top end.... the reeds were opening up way to far under load. i only have 1100 miles on mine and i'm on my third set of reeds.... might be worth checking

 

[gutterball]

subman: I agree its too rich on top, but why? Remember withe all of the aftermarket electronics removed it seems to do the same thing.

Scott: Funny thing I thought of that, the filter come as a filter and a line with two different ends on it that cant be reversed, the only thing that could happen is you could swap the lines where they come off the tank, but I have no way of checking this as my service manual only identifies the line with the filter as the supply line, but you cant tell if it should connect to the left or the right tank fittig.( without a picture)

Jkinzer: I dont feel this is the issue but I will definately pull the throttle bodies and check the reeds to be sure, the reason I say I dont think that is it, is because, this machine ran well on and off for about 3 days, if the reeds were shot would it not be consistently running like crap?

 

[Himark]

Too much fuel is cooling cylinder. Why? Loosing boost? Screwed up control box? That is where I would look first.

 

[EricW]

Did you put the fuel fuel filter in backwards?

Dont think you can do that, filter can only go one way

As far as crossing the supply/return lines that shouldnt be a problem either, at the tank cap one is 3/8" and one is 5/16" fittings.

Hope ya find it. EW

 

[nate18]

gutterball, let me know when you find something out...my 08 800(with 09 top end) with a ovs setup does exactly them same thing. After 3/4 throttle falls on it's face, sounds just horribly fat(scared the crap out of me first time it happened0. Lost boost, o2 sensor goes lean over 18(resets itself). I thought i was lean but was actually to fat. I don't have egt's. Started fouling plugs left and right which when i changed plugs would run better for a bit then back to bad in a short time. Travis at OVS thought i was just overly rich on the top end. I didn't have time to fully figue out what was going on b/4 we lost all our snow. So if you find something with your's please post b/c it sounds like mine is doing exactly the same thine. Thanks.

 

[gutterball]

Himark: This may be a rich condition, but it is likley not a boost related, or a control box issue, I have removed the turbo and all related electronics from the equation, and it still displays the same symtoms.
EricW: thanks for posting the picture, I thought the connections on the tank were the same size, is yours a 2007 or 2008 model 700, mine is a 2007, the 08 is diferent.
nate18: mine started the same way, fouling plugs in 1 mile, change them it was good for a little while and then worse.
It is not a control box issue, I tried adding a ton of fuel, and tried removing a ton of fuel and neither made a noticable difference.If I learn anything I will let you know.
Thanks again to everyone for your input.

 

[Silber]

1. Could be to rich causing the bogging, could explain the low egt's as it will misfire and raw fuel will spray on the probes.
2. Spark plugs have to much gap, causing misfire under hard load
3 Major lean condition, which will pop and bang, also lowering your egt's
I asume your wideband is doing funky things to as when its bogging it doesnt flow enough exhaust and makes it read very lean. Good luck Justin

 

[Himark]

Did you completely remove the jumper wire to the injectors or just the box and used a jumper at the plug? I found a wiring short in the lower harness before causing intermittant open injector syndrom.

 

[SNOW JW]

By chance did your dealer rule out the voltage regulator or put a new one in??

As Justin said plug gap if way out of spec can do this as well.

 

[TEC800]

just throwing this out there, don't know squat about turbos, but is the TPS set right?