Car acting funny in first and second gear

[mkgearhead]

My son has a 1990 Gst that we just replaced the head and turbo on (stock turbo) and it was running fine but yesterday it started to act up between 4 and 5000 in first and second gear like it wasnt getting any fuel or not enouf fuel to meet the demands of boost i was thinking fuel filter or sprak plugs (right now it has bosch Platnum plugs in it) but it only does it between 4 and 5000 RPM in first and second gear so i have ruled out the fuel filter does anybody have any ideas??? Thanks

 

[andymoraitis]

I had SEVERE backfiring and sputtering problems under boost when I first bought my GSX. While I knew the wires needed to be replaced, the major culprit was that the previous owner was using Bosch Platinum plugs in it. Our engines aren't receptive to these at all. Swap them out for a set of NGK's (BPR6ES if you're on the stock turbo) and your driveability issues should disappear. Also make sure these are gapped correctly (I run mine at .028) to prevent the spark blowing out under boost.

Hope that helps,

Andy

 

[Prez]

First off throw those Bosch Platnum plugs away and go buy some NGK BPR7ES Plugs. They work the best in our turbo cars.


May check for boostleaks if the plugs don't fix ya up.

 

[andymoraitis]

Yup, boost leak testing is a damn good idea too.