over boosting

[Al's Clone]

I need a little help. I have a 91 syclone with an atr chip, cat back exhaust and an aux, intercooler.Other wise the truck is stock. I had a problem with over boosting due to the cat being removed. I have replaced the cat with an atr cat, and it seemed to have solved the problem. From a dead stop when i floor it it holds 14psi boost. The problem now is when i am driving along and i punch it. The transmission will kick down and the boost will jump up to 20 psi. This is the only time it will over boost.

I would appreciate any help i can get.

 

[conlyn]

Re: over boosting

it would be worth checking the vac line into and around the wastegate, and replacing them

i didn't know what the hell my problem was, even looked the lines over twice until i pulled them off and foudn the slight crack in one


might work, might not, worth a try though.

 

[wantingasy]

Re: over boosting

Make sure you have the connector plugged into the boost solenoid (black and orange wire) Thats what happened to me

 

[ghettosled]

Re: over boosting

well if your black and orange wire is disconneted it should only make 8psi... I would try disconnecting it, and if you are getting boost spikes similar to when it is plugged in chances are your WG cant keep up with the free flowing exhaust.

 

[wantingasy]

Re: over boosting

mine surely went up to 17psi when that was unplugged and caused it to overboost...

 

[ghettosled]

Re: over boosting

thats cause your wg was not working properly, or your vacuum line was not attached to the wg actuator.. The electrical imput to the selenoid is to increase boost above the 8psi base pressure..

 

[Syclone#2960]

Re: over boosting

It sounds like the new cat is flowing a lot better than the stock one was. Try giving the waste gate rod 2 full turns (reps) to lengthen to rod . This will lower & slow down the boost build up.

 

[nightdiver]

Re: over boosting

Get an external and forget about. Its not that much money to spent in order to save your engine