Boost Problems

nikp · November 10, 2006, 02:20:28 PM

Yeah, so as i was saying, try swapping the electrical connections round on the pre-control and wastegate solenoids - the ones that are bolted to the upper inlet manifold

allstaruk · November 10, 2006, 02:31:06 PM

Quote from: nikpIf you are getting a solid 6 psi from 4,500 RPM up, Check the electrical connections to these two solenoids, as they can get mixed up while working on the engine. From the front of the car, the right hand solenoid and the electrical connector of the engine electrical harness have a painted white dot, these two go together. Note that over time these painted white dots tend to dissapear

But this says if your gettting a soild 6psi from 4500 up I\'m not I\'m getting a solid 6 below 45000k I\'m getting bugger all from 4500 up mate, will check though.

A

nikp · November 10, 2006, 02:36:32 PM

ah, right, yeah. Sorry, my bad. I mis-read.

allstaruk · November 10, 2006, 02:38:19 PM

Thats cool thoght I was going crazy for a min there mate.

Still everything that helps me understand this setup is helping even thought i\'m prob gonna go non sequential.

A

nikp · November 10, 2006, 02:51:22 PM

Yeah, i think the troubleshooting instructions say, remove BOTH electrical plugs from those two solenoids, and you should get 7psi boost from zero to redline.

If you\'re losing boost after 4500rpm, then it suggests something wrong with something that controls the second turbo operation.

allstaruk · November 10, 2006, 03:01:26 PM

Or a leak on the second turbo? The only place that it can leak from the second but not the first as far as i can see is the charge relief valve setup.

nikp · November 10, 2006, 03:07:28 PM

Quote from: allstarukThe only place that it can leak from the second but not the first as far as i can see is the charge relief valve setup.

That\'s what I\'m thinking. These valves can leak. I wonder if you took if off and tried to blow through it, whether you could?

allstaruk · November 10, 2006, 03:19:59 PM

I dunno we\'ll see in min.

A

allstaruk · November 10, 2006, 04:36:22 PM

Right the charge relief valve is good, the hose from it to the car however was not, so boost leak sorted but unfortunatelty the boost problem persists.

I re-connected everything and took it for a drive, Now this is definately an intermitant problem as twice during my test drive I saw a purfect boost patten. The 1st turbo now works fine, unfortunately the second is not being anywhere near as co-opperative it still loses boost, dipping the throttle to re-charge the vac system also doesn\'t seem to be the cure.

I\'m lost.

A

nikp · November 10, 2006, 04:40:27 PM

Charge relief solenoid then? Always open?

allstaruk · November 10, 2006, 04:46:55 PM

Not to sure to be honest mate, I stil need to get hold of a mityvac but now I\'m startin to think maybe I\'ve got an exhaust leak, its sound a little funny, almost like its hunting when your next to the car but when your in it the rev counter is steady, I don\'t think and exhaust leak would cause boost to drop though wouldn\'t it just mean I didn\'t make full boost?

A

nikp · November 10, 2006, 04:50:20 PM

You would find that an exhaust leak would give more consistent boost problems, i would have thought. Boost leaks don\'t tend to leak occasionally. Also, you\'d find the issue accross the revs - unless it\'s the manifold perhaps - which isn\'t unheard of. High milers can develop cracks - mine had the cracks. But i could hear mine had the leak in the engine bay.

allstaruk · November 10, 2006, 04:52:50 PM

I\'m runnign out of time to fix this now which is getting bit crap, also I\'m running out of idea\'s other than going non sequntial a little earlier that I\'d planned.

I\'ve got a boost controller on the way so I might just do that if it comes to it.

Alan