I'm not new here and have been reading posts for quite a while...

I've currently had a 6# lower pulley chnage on a SVTL 01 and have since had problems... The car has had the correct tuning and has a CAI by JLP... Here's the problem...

At half throttle the car is normal and has always been... Once im at WOT the car just won't go! It's like someone put a sock in the fuel line! The car begins to shudder and drop... Im getting normal reading's on the boost gauge... I've had all the sprakplugs changed to NGK (Like they were before) It's been like this for about a month and everytime i ask someone no one knows whats wrong! It's not one of the coils cause ive had those recently changed (bout a week ago)

(PS: The problem is only at WOT not anywhere else...)

NEED HELP! SERIOUS HELP!!!

Thanks!

 

Hey MiMiK
Are you sure it's not Detonating ???
and
When was the last time you changed your Fuel Filter ???

I can tell you that I have experienced WOT problems like this back in 02 and
"it was the Fuel Filter"

Few more questions for you
So your saying it did it before the new plugs, and after ???
But not before the 6lb pulley ???

Was it re-tuned AFTER the pulley change ?
Was it tuned by a L Tuner, any idea of the timing and AF ?

 

Im kinda new so can you please explain what you mean by detonating?

The fuel filter was changed about 2 months ago...

It did it before the new plugs and now still does it after except its worse... before the 6# pulley it did do it but wasn't this bad... Ive had it tuned after the pulley was installed...

But i doubt its the tuning cause to of my bodies have he smae tuning but don't have the problem...

Thanks... Please reply to my post! Im going to buy a filter now! Please reply im stuck on this one!

 

New problem! Back firing! Once im at full throttle! It pops repeatedly!!!

Help!

 

What gap have you set the new plugs to?
They need to be at 34 - 36 and not the stock gaps or the boost snuffs the spark out like a candle.

 

..from Rob02 original question...
Was it tuned by a L Tuner, any idea of the timing and AF ?
What kind of tuning, flash, chip??

 

OK
First off is Detonation (extremly dangerous for a Lightning)
On a normal car it's that marble sound you'll hear when your octane is too low, or your running too much timing. On a Lightning that noise can be very diff and almost impossible to hear (Silent Detonation). And it can destroy a motor in no time.

The fact that you are saying it did it a little before the pulley but more now is scary, sounds like you are having Detonation, hence the reason 0light1 wants to make sure you understand what we're asking. A Non Lightning Tuner may not understand how timing sensitive a Lightning is, and more important how dangerous a lean AF mixture is

Why we're asking is it sounds like your timing is set too high, "or" your running too low octane. If you happen to not know this, "you MUST" run the highest octane and grade available on the Lightning. 94 octane if possible, 93 octane AT THE LEAST. Less octane or a bad grade of fuel can also equal death on a Lightning.

Now the worse news, if what your explaining is what I think I'm hearing
At the best you cooked some spark plugs, And thats at the best,
(unless you have a differant issue outside the norm)


Keep us up to date, AND GOOD LUCK

 

my truck did this same thing. ended up being the plugs were fried. to much timming for the level of mods you have will do it. put a fresh set of tr6's in @ .034 and youll be set unless you have just to much timming

 

Were running a 93 octane and the tuner is lightning tuner who works at the modular performance center here in Kuwait... He warned us bout the octane problem... I'll have to check the spacing on the Spark plugs... THis happened before and turned out to be that one of the coils was basically destroyed so im having those check and replaced if needed...

As for the questions:

1) Flash or chip?
It was chipped...

2) As for fuel...
93 octane and above... The highest fuel octane available basically...

Ill have to check on the timing and get the numbers from the tuner... This is a headache! It's been like this with the plugs and coils ever since i got them!

Some guys on SVTPerformance.com said it might be a Gasket and others said it would be the fuel pump...

Whats funny though that when it's at Idle its normal even if i put my foot to the ground... Nothin shudders! It's also normal untill 4100RPMS! I don't get this! Will get the stuff checked and keep you posted!

 

maybe one of your 2 fuel pumps is bad????

 

Very good possibility that you got a bad batch of fuel. If it had water in it, it will take a few tanks, along with some fuel additive to dissipate the water, to get you back on track. This happenned to me a while ago.

 

Ah but you just mentioned something "COILS"
They can be a MF to trouble shoot
A bad coil usually WONT throw a code, and in most cases will work fine untill high RPM (making it even harder to trouble shoot)

For the record when ever I cooked a plug it would back fire, thats what made me think bad plug/plugs, and a bad plug or three will actually fire fairly normal under normal driving, but spudder on high RPM

If you have a multi chip, you may want to try a 14/15 degree program...

 

Im going to check it today! I hope its bad fuel or just a plug or coil those things are a quick fix! Other than that im pretty much sure it's electrical or with the fuel!

 

My guess is this.....

I would say plugs/coil, but you've changed them and it still did it. They could be damaged again from the current problem, but I don't think it's the route cause.

Fuel filter is 2 months old. Anything could be in there. If it did it before you changed it and still does it, probably not it, but cheap fix if it is.

The fact that it does it at WOT makes me think that it could be in the tune, but probably not likely. I'm going to say either a bad fuel pump relay..........bad fuel pump.........or you had one of the hoses pop off the tank.

I've done ****loads of research on problems like this. Mine turned out to be a coil pack the first time, and a tune issue when I switched to headers and high flows the second time.

 

Why don't you try pulling the chip and take it out for a spin.

:santa: