Perplexing Idle Problem

Justin

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Mar 31, 2005
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Spokane, Wa
I am having a problem with the 88T. It is having trouble idling, as well as terrible throttle response. I have taken three ZT2 Wideband logs and two videos that will be at the end of this paragraph. The mods to this car are as follows: SP58GT, VPC, eMan, e01, ZT2, Catch Can, Defcon DP w/ 3" open exhaust, 550's and a Walbro (I think that's all that is relevant)

<throttle response problem>

Lets start with the throttle response problem. This was happening slightly before the VPC, SP58, 550s and Walbro were installed, however the problem has been exaggerated severely since the install (as the video will show)

Here is what happens: I will be sitting, idling around 650 smooth as can be. I will floor the pedal and the car will bog down terribly, I swear the RPMS drop, but they don't according to the ZT2 logs. There will be a horrible hiccup where the car attempts to die and then it'll start climbing and the exhaust will humm away...

When I'm cruising along enjoying the weather with the top off and floor it, there will be a slight hesitation, however nothing as poor as what happens at idle.

</throttle response problem>

<idle problem>

on to the idle problem. We’ll start out with me in any gear going full throttle, full boost till redline. when I shift into neutral to slow down the tach will fall down to around 200 RPMs then catch itself and climb back up to ~650

if I am just treating the car nice, driving around a neighbor hood or by a cop, nice and easy and let the RPMs drop the tach will fall down to ~650 and stop. no hiccups or anything!

I've also noticed sometimes I will turn the car on and it will idle llloooowww, below 500, then after a few moments it will bring itself back up to ~650

</idle problem>






Standing Still, Revving (small file) .zto extension


Way home from my G/Fs (small file) .zto extension

Way to my g/fs (small file) .zto extension

Video From the outside of the car (5 MB File) .mpg extension Pay close attention to around 7 seconds

Video From inside (20 MB File) .mpg extension

Link to .ZTO reader
 
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siman

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Mar 31, 2005
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Word from the wise.

The more you "mod" your car, the worse the idle will be.

As for the throttle response. Have you checked your codes lately? You may have a TPS code in there....I know I do and its KILLING my power on low end! But the Lex afm makes up for it on top end....lucky you running a VPC.

The VPC thought may be to blame. If I am correct those you VERY slow 8 bit or less processors....remember, that is a PIGGY BACK interuption type computer that converts the AFM signal into map based signals...and reverts it back to the computer as an AFM signal.

Maybe its just OLD technology and you wanting the "new" feel.....its not going to happen.

Just like buying an old FCON for our cars......its just NOT going to compare to nowdays electronics and their speeds to inherently "change" the performance of the car on a whim.....

and you have your (HKS??) VPC mated to your E-Manage?? THAT could be your problem again.....old and new technology piggy backs really dont belong together....if your going all out, go all out. Dont substitute.

at least this is what I have gatherd from my personal friend in town that had a 518whp mk3....

-Jonathan
 

Justin

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Mar 31, 2005
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forgot 'bout this thread :)

The problem turned out to be the fuel pump and the 12 volt mod. I applied constant voltage to the Fuel Pump and it fixed the problem.

all the files are gone because I pulled 'em off my server.

and there are alot of people running vpc/eman with no ill effects. LIKE ME! :)
 

siman

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Mar 31, 2005
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Justin said:
forgot 'bout this thread :)

The problem turned out to be the fuel pump and the 12 volt mod. I applied constant voltage to the Fuel Pump and it fixed the problem.

all the files are gone because I pulled 'em off my server.

and there are alot of people running vpc/eman with no ill effects. LIKE ME! :)

Thats great to hear! I just thought I would put some speculation into that situation pertainting to the two individual computers working together....thats like a Knight from the 12th century and a soldier from WWII working together to fight aliens...LOL

I guess it can work though.... :icon_bigg

-Jonathan