Breaking up/Jerking & other problems
Feb 7, 2010, 01:06 PM
#1
Breaking up/Jerking & other problems
My buddy came over with his Evo IX Mr last week which he recently bought and said the car was fine until recently.
The car has:
TBE
MBC
Intake
and the HKS SSQV bov.
Then I saw the car under the hood and it was a total mess! Beyond recognition. My friend said the car was bucking/breaking while in WOT and sometimes when cruising too.
So i do a boost leak test and guess what - the wastegate was completely broken!! Changed that one with another one I had at my place and then did a boost leak test. Lot of leaks here n there that I got them all fixed. While at it, I wanted to have a look at its MAF sensor and boy that thing had oil n dirt all over it!
Changed it with another one and removed the lousy MAF and replaced it while doing the rest of the Boost leak testing. Everything fixed and I did another boost leak test. The BOV was leaking so I thew in another BOV and the leaks are down to zero.
Now I drive around and from 1st gear.. the car was really heavy. AFR read 16's and then suddenly back to normal. 3rd gear and I push the car and the car builds boost - startes jerking- builds boost- starts shuddering and then afrs are @ 10.0!
No clue as to why this might be the case. The weather suddenly got colder but I dont think it would affect it this bad.
Thanks in advance. If not.. i will try changin the cam sensors tomm and give it a try. Till then I appreciate all the feedback!
The car has:
TBE
MBC
Intake
and the HKS SSQV bov.
Then I saw the car under the hood and it was a total mess! Beyond recognition. My friend said the car was bucking/breaking while in WOT and sometimes when cruising too.
So i do a boost leak test and guess what - the wastegate was completely broken!! Changed that one with another one I had at my place and then did a boost leak test. Lot of leaks here n there that I got them all fixed. While at it, I wanted to have a look at its MAF sensor and boy that thing had oil n dirt all over it!
Changed it with another one and removed the lousy MAF and replaced it while doing the rest of the Boost leak testing. Everything fixed and I did another boost leak test. The BOV was leaking so I thew in another BOV and the leaks are down to zero.
Now I drive around and from 1st gear.. the car was really heavy. AFR read 16's and then suddenly back to normal. 3rd gear and I push the car and the car builds boost - startes jerking- builds boost- starts shuddering and then afrs are @ 10.0!
No clue as to why this might be the case. The weather suddenly got colder but I dont think it would affect it this bad.
Thanks in advance. If not.. i will try changin the cam sensors tomm and give it a try. Till then I appreciate all the feedback!
Last edited by evo_q8; Feb 9, 2010 at 08:54 AM.
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Feb 8, 2010, 10:25 PM
#9
well here is the story. My buddy wanted to act all "Mr. I know" and got his AEM EMS on the car and started playing around with it. Well... didnt quite run well so he swapped it back with the OEM ecu. Since then the cars been an ***!
It was tuned for those mods previously. But now...its just acting up all crazy! For some reason.. it feels like somethings acting up with the mivec...
It was tuned for those mods previously. But now...its just acting up all crazy! For some reason.. it feels like somethings acting up with the mivec...
Feb 8, 2010, 10:44 PM
#10
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Pulling hard up through RPM range and then violent bucking is usually boost cut or fuel cut. Most likely boost with the MBC cranked past what the ECU threshold is set for.
Do you have any means (Tactrix cable + Ecuflash) to check?
I'm guessing the HKS BOV is VTA? Probably fail point #2.
Leave the cam angle sensor alone.
Do you have any means (Tactrix cable + Ecuflash) to check?
I'm guessing the HKS BOV is VTA? Probably fail point #2.
Leave the cam angle sensor alone.
Feb 8, 2010, 10:53 PM
#11
Yes. I feel its fuel cut. I see the wideband hitting 10.0's. Have zero boost leak. changed his bov to a recirc bov and his crappy MBC to the perrin inline. Still the same.
I have the cable and ecuflash. What do u want me to check?
I have the cable and ecuflash. What do u want me to check?
Feb 8, 2010, 11:05 PM
#13
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Oh boy.. dude, you need a reflash, remap everything.. The car was tuned on the crap you had on there before. good job getting everything cleared up. Just an observation, but Im guessing there was another turbo kit/mods on beforehand with the AEM. I would sell the AEM, unless you plan on going big. Basic ECUflash will do the trick as you sit now with possible mods later. definitely have the plugs checked.. Good Luck
Feb 8, 2010, 11:10 PM
#14
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