Won't boost past 10 psi, studdering, Please Help!

[89_laser_32]

Ok I bought my 1990 laser rs turbo with a blown head, replaced it, run 14 psi for 2 days, then it quit pumping oil and bent valves. Switched the valves, got good compression, but my car will not hit 14 psi. Sometimes when the engine is cold I can get it to do 12, but I know what a turbo laser feels like when it hits 14psi...and my car is not doing that. When I give it gas it will pull like normal then when it hits 10 psi of boost it just stops pulling and bogs down. Also it seems like its running rich. Could it be my crank angle sensor or TPS causing it to not distribute the right amount of under boost? Please help i'm lost. Also is the tps interchangeable from turbo's to non? Thanks for the help.

 

[theghost]

Did you check the turbo for shaft play or oil leakage? You should see a cloud of black smoke from the exhaust when you feel it bog if its running that rich. Do you have any type of datalogging device or fuel management? yes the tps is interchangeable between turbo and n/t. Not really sure what you're problem is but I would check these things. Also check your plugs and wires. Good luck

 

[theghost]

You could also have a boost leak do a test and check all your connections between turbo and throttle body

 

[89_laser_32]

How do I do that leak test? I've seen something about using soap water but not really on what to do.

 

[ddavisaf]

theghost is the only one to have actually suggested the right thing so far.
Stutter under boost is a sign of a poor ignition system.
Check your plugs and wires.
You MUST have NGK BPR6ES spark plugs gapped at .028". Nothing else will work for stock or near stock cars.
Ohm your plug wires
Ohm your coil pack's primary and seconday coils.

If THAT doesn't work, run a boost leak test.

 

[oldman]

theghost is the only one to have actually suggested the right thing so far.

Maybe it's because he is the only person who had replied so far.

 

[oldman]

How do I do that leak test?

http://www.vfaq.com/mods/ICtester.html

 

[ddavisaf]

Wow... you're right...

I just saw a bunch of posts and didn't pay any attention...
I'm done for the day
I'll see y'all tomorrow.

 

[89_laser_32]

Just an update on my issues: My car can't boost past 10 psi and it still boggs down really bad when it hits 10. It's seems like its just cutting the fuel when it hits 10lbs of boost. I'm having some strange timing problems as well. It won't hold timing longer than a few minutes. There is also a strange missing coming out of my head...kinda sounds like a ticking and hissing sound...and it gets worse whenever I hit 10lbs of boost and it boggs down. One more thing...whenever I take the electric connectors of the injectors only 2 of them actually bogg down the motor really bad. So, timing issues, fuel cut, missing, idle surge= Crank Angle Sensor? Thats my best guess. PLEASE HELP??!?!?!?

 

[ddavisaf]

If it were your CAS I doubt you'd be able to even get close to 10 psi. So at the moment I don't think that's your problem.
I sent you a PM concerning this issue, but I'm going to throw it out here so others can follow the thread.

Idle Issue- Check your ISC
The 10 psi problem-Run a boost leak test
Everything else-Check the capacitors in your ECU.

If all three of the above mentioned check out good, try rotating your CAS 180°. Or you can try it first... which ever you'd prefer

 

[ndm1]

Which two injector plugs affect the way it runs?
With it being two of them as ddavisaf said before check your coil pack.

 

[89_laser_32]

number 1 and 4

 

[ndm1]

I don't have the manual in front of me but I believe that 1 and 4 come off of the same side of the coil pack and 2 and 3 on the other.
So I would definitely check it first.

I am sure someone will verify that for me.

 

[steve]

I am sure someone will verify that for me.

That's correct.

Steve

 

[ddavisaf]

Your coil pack controls your spark plugs. There's a resistor box on the firewall for your injectors that may have gone bad, however we'll not worry about that at the moment. Check everything else first, and then once we've ruled out all of those possibilities we'll take the appropriate steps.

 

[89_laser_32]

Should I have mentioned there is an extremely strong exhaust smell inside the car whenever the turbo boosts? That's not normal is it?

 

[89_laser_32]

OUCH....60 compression on 2nd cylinder... and I just had the valves switched out...guess they didn't seat right or I got a crack in the valve seat. All in all, I hope that it's the only problem and it's causing everything else. I'll keep yall updated.