Bumpy acceleration, intermitant, 2nd turbo

[Dodge]

hi peeps, ive trawled the threads and found numerous threads like this, but nothing that is exactly like my problem.

 

was driving normally about half hour ago, and put my foot down a bit to get round a car, and as it came off the 1st turbo into the 2nd it bumped about a bit. like bumpy acceleration symptoms, such as jerky motions, (only 1-3 jerks before it carries on as normal)

 

it happens once out of ten attempts in low gears, but at 30 mph in 4th, if you boot it and let it go right round the revs, its very prominent right at the 2nd turbo coming in (4k revs)

 

NOTE: im spraying my dash, fitting sterio, and loads of other stuff, so pretty much most of the dash is in pieces. could it just be that? i doubt it but thought id make note of that. NO ecu's are unplugged, just a/c controls etc

 

also i noticed the problem is not as bad if i turn the traction OFF

 

help!

 

[Swampy442]

Check your coil pack clips

[Dodge]

UPDATE: just took it for another drive, the slip control makes no difference. the car runs at 1 bar standard. it is 90% ok here, unless your low speed in high gear and floor it, then it gets a bit jerky. 2nd gear runs are fine.

 

with boost controller on, at 1.2 bar it bumps all over the place and im scared to let it go through the revs its that bad.

 

i also forgot to mention in the original post, as weird as it sounds, that the SECOND this came up, the car is feeling quite a bit more responsive, AND first turbo pulls a bit harder. just feels faster and smoother, except the bumpy jerking at around 4k revs when the 2nd turbo comes in.

 

WIEEEEEEEEEEEEEEEEEEERD

 

any thoughts/similar instances?

[Ian C]

What he said up there. Check your coil pack connections. As ignition starts to break down, you'll see intermittent misfires at high boost levels - this is why you get it more in higher gears, you're on full boost faster and longer. The intermittency of this problem makes it very easy to jump to false conclusions about what does or doesn't change the behaviour of the problem - I doubt traction control on or off actually affected it.

 

It'll get worse over time, at lower and lower boost pressures. The coil pack clips start breaking down fast once they are on their way out. It might even be the coils themselves, but only look at them after checking and replacing the connectors.

[Dodge]

i checked the connectors, they look fine, the car has only done 60k miles. the connectors look really good.

 

should i check for resistance and voltage capacity etc?

 

thanks for your help btw guys!

[Muffleman]

I presume you have a boost gauge, what vacuum do you have at idle ?

[Dodge]

280 mmhg +/- 10

[Muffleman]

Would expect to see nearer 600-700 on a healthy engine mate, have a look for split hoses off the inlet manifold, especially the one running to the fuel regulator. They're always worth renewing anyway

[Dodge]

oooh, ok. that is off my boost controller reading. my greddy boost gauge says 500 ish but i thought that wasnt reading right!!

 

as it reads a little bit under 0 when the engine is off or the gauge is unplugged.

 

the hoses are all relativity new as previous owner had all new red ones put on.

 

ill check all over though thanks