MSP Severe Jerking

[bayanrabbani]

My friend has a 2003.5 MSP with an Injen Cold Air Intake and an HKS Turbo Timer. Since November of last year he said the MSP will jerk violently from about 3200rpm up till 5000rpm+ regardless of the amount of throttle; it will also occassionally idle rough, and also has periodic check engine light stating the Injector Bank 1 is running lean. The problem gets a lot worse when it is cold outside, i.e. it barely happens in the summertime, but in the wintertime it gets really bad. It also gets worse while the turbo timer is on. He said the problem started after 1 of 2 things: he got his first TX inspection done in Nov. 2005, or it could have been when he took it up over 100 under hard acceleration.

He looked at all the vacuum lines and made sure they're tight. After checking all the lines, putting some fuel injector cleaner in the tank, and taking it to the dealer (told him to take off the CAI and put the stock airbox on) it still does the jerking. He loves his MSP, and he really wants it fixed. Any suggestions?

 

[jestermsp]

get a wideband n boost gauge n see what the car is doing while it happens.

 

[blthlt]

It sounds as if your friend is hitting fuel cut. When it's summer the air is less dense therefore the mass airflow sensor (MAF) doesnt max out and hence he doesnt have the issue. When winter the air is more cold and dense therefore the MAF cuts ignition to the plugs. There are a few ways around this problem, the one I WOULD NOT!!! recommend is any type of fuel cut defenser. Is your friend running stock boost?

 

[Blake]

Check the wastegate please!

 

[bayanrabbani]

Yea, the boost is stock

 

[OrngSpd03]

Same problem. Dealer replaced the wastegate which solved the problem. Then they found oil leaking out of the turbo and replaced it but thats a different problem.

 

[Kypatrick]

Same problem. Dealer replaced the wastegate which solved the problem. Then they found oil leaking out of the turbo and replaced it but thats a different problem.

Has everybody had a wastegate problem?
Wonder when mine is gonna is gonna fail!

 

[03MSP]

Mine is still goin good so far (over 40,000 miles)

Definately sounds like fuel cut, kicks in pretty early when cold.

 

[OrngSpd03]

I was looking at my service invoice, the pice listed for the wastegate actuator was $374.85. Aren't acuators $60?

http://www.atpturbo.com/Merchant2/m...p&Product_Code=ATP-WGT-011B&Category_Code=BCS

 

[03MSP]

I was looking at my service invoice, the pice listed for the wastegate actuator was $374.85. Aren't acuators $60?

http://www.atpturbo.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=tp&Product_Code=ATP-WGT-011B&Category_Code=BCS

Invoice from a dealer? If so I wouldn't be surprised...

 

[Pmpkinhead]

My Waste Gate Actuator (WGA) just failed and was replaced ($500.00 US). I am completely stock with over 40K miles. The car spiked between 3K and 5K RPM, it was like ridin' a bronco! Dealer said the boost will go beyond 10PSI when it fails and I will notice a lack of power when it is fixed because the boost level will be back where its safe for the MSP engine. Sounds like you have the same problem. If your not under warranty, buy the "fixed", not adjustable, aftermarket WGA for $80.00 US. Do a search for WGA and you will find all of the info. In fact, we just had a major thread on this subject about 3 weeks ago.

My CEL came on for a day before the WGA was replaced but I did remove the gas cap with the engine running by mistake back then. I don't know which one caused it.

367 (mp3yellow

 

[jmv]

actually the atp wga is $60. But its not adjustable, not stock, yadda yadda./...

 

[OrngSpd03]

The stealership forgot to tighten the clamp on the intake pipe at the turbo when the replaced everthing! Damn thing shook itself off. Got a CEL and car started running bad. Jacked it up on the side of the interstate crawled under the car and tightend it back down with a plastic knife I had in the car. Burned myself good on the turbo. Need to start keeping mechanic's gloves and tools in the trunk. Calling the service manager today. Woder what he will have to say about it!

 

[Mutmatt]

i was going to say check all piping ie- top of SMIC, bottom of SMIC, TB, turbo intake, turbo outlet. and make sure they are all still attached

 

[Kooldino]

My initial guess is a MAF issue, or something related to the MAF.

 

[Kypatrick]

actually the atp wga is $60. But its not adjustable, not stock, yadda yadda./...

So you can replace the WGA for $60? Do you have a link to that website that sells it. The only other fix i have seen is the stupid $356 kit from ***************

 

[nazgul350r]

I am having the same problem but my tubro charger assembly was replaced.

 

[Rush]

Holy s***, I'm glad I found this thread.

Sporadically, my MSP does something very similar -- but it does it only when I'm jumping on the gas, and NOT every time. If I put the gas pedal down hard from any lower RPMs, the car will occassionally jerk like mad -- but as soon as I take my foot off the gas, and then press back on more gently, it's smooth and fine.

I've managed to have it happen not as 'harshly' a few times, during which I've watched my boost gauge -- nothing, it's steady. And the few times the car has started bucking HARD, I've thrown a CEL. But the CEL is always gone by the time I'm able to get to any shop to have it diagnosed.

Does this sound like it's falling under the wastegate problem, too?

 

[Pmpkinhead]

Yes

 

[mzdalvr]

Not to throw a wrench in this post, but my N/A protege started doing this too. The explaination from a few places suggest that my fuel injectors are clogged, clutch may be going, or thats how the transmission is (I'm like pick a card, any card at this point).

Mine usually does this when i shift into second or down into second and at low rpms try to step on the gas and the car bucks pretty harshly. I don't know if this is the same thing your experiencing, but I'd be happy to know if anyone has any ideas on what this is.