Power pulse

[Guest subist]

Hi,

 

I've got a 92 Gt legacy turbo. I recently found that the outlet for the tubro boost controller solenoiud vale had been deliberately blocked up! I cleared it & now the car boost much harder BUT the power pulses baldly, especailly if you put your foot down! What may cause the power to fluctuate quite badly (while maintaining fairly high boost)? It tends to pulse less when you only put your foot halfway down. maybe the knock sensor? I've put in higher octane fuel (98 instead of 96) & it made no difference.

Thanks for your help.

 

Luke

[Guest Legacy777]

Luke,

 

may want to check out <a href="http://www.bbs.legacycentral.org" target="top">legacy central bbs</a>

 

Alot more turbo owners over there, which can probably help if you can't find an answer here.

[Guest Strakes]

The car is designed so that the turbo doesn't overboost the engine. If overboost is sensed, then the fuel cutoff kicks in, temporarily shutting the car down...but since you back off the gas, the car starts up again. It's kind of like the fuel cutoff at redline. Since the overboost controller valve has been deliberately plugged, then I bet someone was trying to circumvent this feature in order to gain more performance/boost, or there was a problem with this overboost controller and they couldn't afford to replace it. Anyway, diagnosing and then correcting the problem may be a long and drawn out procedure. I had a similar situation on a turbo-charged car that I used to own. The previous owner had made an elaborate system of wires and vacuum hoses to get more boost. I spent a long time chasing it down (un-doing the tangled mess) and I finally gave up. I then paid a mechanic to fix it...and it took him about 2 hours.

 

Ask the guys on legacy central bbs...like Josh said. They might have a solution that's better.