Hi guys i have a Greddy Profec II boost controller, my mate owned the car (1994 turbo 2000 uk with tdo5 boosting at 1bar) before me and it worked fine, turned it on for the first time since i have owned the car the other night and on full throttle i get a lot of jerking, is this hitting the fuel cut? or is it sumthing else?

Regards,

L J

 

If the 'jerking' is severe i.e. as if someone's rapidly switching the engine on and off, and it's like hitting a brick wall, then yes- that's fuel cut, meaning you're overboosting. Never used a boost controller myself but first thing to check is what the boost setting actually is. 1 bar should not be a problem.

 

yea i was just setting it up to boost at 1bar but it still jerks very hard as you described, dont know wot i can do differently

 

should i get a HKS fuel cut defender and an uprated fuel pump?

 

it may just be dodgey coil packs or spark plugs! any idea what boost she's running with out the controller?

 

1 bar is probably fuel cut as the Turbo UK fuel cut is seat at approx 1bar.
this will be very vilolent though and not just s miss-fire.
A miss-fire is more likley to be coil packs, see Damaged Coilpack

 

well i cant see it being the fuel cut as the owner said his mate used to own the car and it ran fine at a bar!

unless your not running it on the same settings??

is it spiking at all? if yes then i could see it being the fuel cut

 

the settings were changed due to a young person fiddling! hence y i was trying to set it up, should i try setting it up to run at a lower boost? what would be a save amount of boost?

 

try setting it at 0.9 and see what happends? could you see it spiking at all?

 

what is spiking exactly? im new to this turbo stuff

 

Say you've set your car to run at 1bar, when you put your foot down it spikes to say 1.1 and then back down to a bar! catch me drift?

 

ok, i couldnt realy say as i was just tryin to set the controller up at the time and couldnt get it to jus run normaly lol i shall try setting it at 0.9 bar and let you know the outcome. Thanks

 

no worries mate

 

ok guys, went for a drive last night (without the boost controller on) and occasionaly when using full throttle i get a missfire around 3.5/4k revs, could this b a coilpack breaking down and be causing the problem with my boost controller???

 

check the plugs /coilpacks (easy enough to do).