Performance Computer, now only 5 psi

[tommyturbo]

Ok I am stumped. Put a fwd performance computer in my 89 GTC 2.5 TI auto.

With the factory computer it ran the 7 psi till 3000 rpm, and ramped up to around 11-12 at 4000rpm. Just like it was suppose to.

New fwd computer 14 psi setting, can't get more than about 5 psi out of it. However it will boost to 10 psi if you power brake while sitting. I did get it to run up to 14 psi once the first time I took it out driving after changing computer. No fault codes. Does it take that long to learn it wastegate control?

I am stummped.

[forcedfedmopar]

put about 50 miles on it and then report back.

[tommyturbo]

So I've been driving the car, and it will sometimes boost to 14 psi like it's programed to, and other times I still only get 5. There is no predicatability to it yet. I want to know when I get on it that it will boost and not be a slug.

Although it tends to be more prone to pull 14 after already being moving, like stabbing the gas and it takes off like a rocket. The one time I got it from a stop it was insane, it pulled supper hard and when it shifted from 1st to second man did it yank the wheel.

[tommyturbo]

Since my last post, want to update. Ove the weekend was able to convert the car over to intercooled, added factory intercooler, radiator, intercooler hoses, turbo II cruise servo and bracket.

Of course to do all this I had to remove the battery and tray to make things easier. Since doing this I still am only getting 5 psi most of the time, although sporadically I can get 10. No fault codes. Drove car 50 miles so far...how long does this take?

Also am curious, the factory 2.5 airbox had the blow off valve in side, and I simply capped off the vacuum line that ran to the blow off valve. Would that make much difference? from best i could tell it simply went to a vacuum source in the manifold.

[forcedfedmopar]

yea_it_goes_to_manifold_vacuum.It_(the_valve)could _possibly_be_leaking_tho.

[tommyturbo]

Since I converted it over to intercooled I removed the stock 2.5 airbox (no provision for the upper intercooler hose) which had the blow off vavle, and just capped off the little vac line that went to it.

But what about the boost?

[bakes]

how do you have the vac lines to the WG solenoid plumed t1 or t2 style
it might be dumping when it should be holding preasure.

[tommyturbo]

I haven't changed any of the vac lines for the wastegate. All the vac lines are the factory 2.5 set up. Only thing I did was cap of the line for the 2.5 airbox blow off vavle which appears to go to manifold vac source.

[bakes]

but the cal might be set up to a t2 wasegate setup and you might be running it on a t1 setup

[glhs727]

PM sent

[Spraynlog]

If you are still using the original vacuum lines, they may be cracked and causing your problem. Look closely at them, and see if they are age cracked,
They could be ballooning under boost and losing your pressure.

[tommyturbo]

Cindy was right, had to swap the cap and the vent on the wastegate solenoid. I guess t-1 and t-II solenoids are different sometimes. Thanks Cindy!

[bakes]

Thats what i was saying!!!

[Spraynlog]

Thats what i was saying!!!

Good call! I'll give a couple brownie points for that one.

[tommyturbo]

Thats what i was saying!!!

I didn't realize it was in the way the lines where attached to the solenoid. There are some other differences in the vac diagrams and thats what I thought you were getting at. I still appreciate all the help and suggestions!