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Discussion Starter #1
When I go raceing and snap change from 1st-2nd- my car jerks about 3 times b4 going. What can be the cause of that. It is a mk2 with the 7mgte conversion. Doing 150km/h in fith and putting pedal to the metal the same thing happens!! pls. I need help!!!
 

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it sounds like axle tramp/hop, just from the quick description, but i didnt think IRS cars got that problem, maybe its just wheelspin??
 

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dogstar said:
it sounds like axle tramp/hop, just from the quick description, but i didnt think IRS cars got that problem, maybe its just wheelspin??
It could be axle tramp/hop. From what I recall, Ross P from the mk2 list had this problem in his 7m-gte mk2...

What kind of suspension setup are you running? If you're still running the standard stuff that hasn't been replaced in a while that could be the problem.
 

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You're hitting fuel cut, bud! Not sure what setup you have (stock or modified) so we can't help ya unless you tell us what you've done to your 7mgte. If it's all stock with shimmed wastegate then you've definitely hit fuel cut. You gotta back the boost down some and do some proper upgrades. Also, make sure all of your ic hoses are in good shape and not leaking at hose clamp connections.

BTW, I doubt it's related to axle hop as he said it jerks in 5th!
 

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I really doubt he's hitting fuel cut, especially if it will take off in fifth after the stuttering. My car did a similar thing and it turned out to be the accelerator pump feature on my ECU. It was dumping to much fuel when I stepped on it so I turned it down and it runs very well. I don't know if the 7M has something like this but it's worth a shot.
 

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Discussion Starter #7
I'm running the 7m still in stock form. I have the 7mgte feul pump installed! Could it be a feulproblem, if ,how do I fix it?

I have a suspension teqnique suspension upgrade and the rest of transmission is still a ok!

Some times, especially in mornings the car does not do it and then she really goes well!!

pls. help!!!
 

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Discussion Starter #8
Racefiend said:
Do you notice a stall when you rev also? Could be a bad TPS.

She revs smoothley.
 

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hmm, stock? Using a 7mgte fuel pump shouldn't be the cause. If you still retain a 7v/12v fuel pump setup instead of using full time 12v then I would check the action of the fuel pump relay while driving under the same condition causing the stuttering problem. Get a couple long (5', 12-14 gauge) wiring and hook up to E1 and Fp terminals in the diagnostic block (in the engine bay which is part of the 7mgte engine wiring loom) to a digital voltmeter (with you in car). Then go for a drive and check fuel pump voltage action. It should register approx 10v then switch over to 12v without any hesitation when accelerating.
 

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Discussion Starter #10
Thank you for your help so far. I really appreciate it. I didn't install the 7m feul pump regulator, just bridged it out on the old afm wireing!! Coul be the problem then!! Must it split between 7v and 12v or could it run constandly on 12 volt?
Will check ic pipes for leaks as well!
 

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It could be running to rich and bogging from your description. The car should run fine with the pump running full 12V all the time. Does the car have any codes?
 

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Discussion Starter #12
no fault codes at all. Once gave a knock sensor code, but that problem dissapeared with sensor replacement. Does the old 5m run a 12 or 7v feul pump supply?

Why does it run smoothly when engine is cold?
 

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Discussion Starter #14
I fitted a brand new clutch kit, do not think that is the problem, it feels as if the engine dies down and ignite again. I wish I could explain better what the car does, all I can say it jerks about three times on a snap change and it feels like the engine wants to stall. Could it be the blowoff that have a problem , or feul pressure?
 

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MikeD said:
hmm, stock? Using a 7mgte fuel pump shouldn't be the cause. If you still retain a 7v/12v fuel pump setup instead of using full time 12v then I would check the action of the fuel pump relay while driving under the same condition causing the stuttering problem. Get a couple long (5', 12-14 gauge) wiring and hook up to E1 and Fp terminals in the diagnostic block
Eh. I just tried that and blew the EFI fuse! lol
 

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Re: jerky 7mgte

supra_mkii said:
When I go raceing and snap change from 1st-2nd- my car jerks about 3 times b4 going. What can be the cause of that. It is a mk2 with the 7mgte conversion. Doing 150km/h in fith and putting pedal to the metal the same thing happens!! pls. I need help!!!
Check for vacuum/boost leaks. Today I just found 7 freaking leaks on vac lines and IC piping! It runs much better now but not perfect. If your 7m is heathy it should idle at about 21 inches if vacuum. Anything less than that with a warm engine then it's likely you have some leaks.

If you don't have any leaks test/replace the TPS. Also, the mechanical-spring-loaded-catch-lever portion of the TPS (connects to the TB) can get gummed up. I cleaned/oiled the one I thought went bad and it worked fine afterward.
 

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Discussion Starter #17
could it be a feul spike? :lol:
 

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WadeT said:
Check for vacuum/boost leaks. Today I just found 7 freaking leaks on vac lines and IC piping! It runs much better now but not perfect. If your 7m is heathy it should idle at about 21 inches if vacuum. Anything less than that with a warm engine then it's likely you have some leaks.
Are you serious Wade? Idle as in engine warm at a stop light? 21inches of vacuum? Boy do I still have major issues. My 7mgte has never Idled anywhere near that high.

Leslie
 

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Discussion Starter #19
Where can I get hold of a set of 550cc injectors? I'm hopefully getting a lexus afm soon. If I don't get it is there anybody out there that's got one for me? This might hopefully solve my problem. Upgrading. Hoping it is a feul spike problem. :?
 

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Discussion Starter #20
Bought my afm, just waiting for shipping. Still looking for injectors :(

What do you guys think, could this be my problem?
 
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