Car hits 8 psi and breaks up

[86ShelbyZofDoom]

The previous owner of my car said I needed to install a (granger?) valve on the line from the turbo to the boost solenoid..if I understood him correctly. The problem is as follows-

The car can't go WOT.. if I do so, the boost hits about 8 psi and the engine starts to stutter (and subsequently refuses to rev any further) and the gauge starts fluttering rather violently between 6-10 psi. At 5-6 the engine is just fine.

Mind you, though a swap is coming, its still a TI motor.

And while someone's at it, since this is my first turbo Dodge (somewhat different from a Grand National and Z06), what can the TI motors handle safely boost-wise? All the car has done to it is a Mopar Stage II computer (I think it is stage II as per the dude) and a 2.5 inch exhaust.

Thanks for the input!

[my89daytona]

my car did the same thing, after much stress and pain in the ass, i found two problems, one being cam timing mine was one tooth off and did the same thing, reset timing belt and fixed the problem, other time i saw it was in the drive shaft for the oil pump being off a tooth, making timing permenantly off.

[Sittn86]

A grainger valve doesn't go between the solenoid & wastegate, it is used instead of the solenoid.
Check out these pages, they'll probably answer all your questions & more:
Donovan's Dodge Garage
MiniMopar Resources
www.DempseyBowling.com
Gus Mahon Homepage

Welcome to the board!

[86ShelbyZofDoom]

Plus, as a little footnote, the other day I noticed more symptoms..

The car seems to not hold steady boost in 2nd gear.. itll go past 4000 rpms then the gauge just creeps up exponentially (I believe I spiked to 16-17 in 2nd the other day prior to the engine breaking up and refusing to rev past 5000).

I mean, not that I really want to beat on a motor with 184500 miles on the ticker but i haven't seen WOT successfully. Help help!

Oh, and I read the articles about checking my timing, but why the boost creep if its just timing?


The only mod is a Mopar stage 5 computer (supposedly), as the stocker is in a box in my trunk.


And can this motor and trans combo withstand any modification whatsoever? I have a turbo II motor in progress with a t3/t4 and a spare 555 trans, but itll be a while and I might as well have fun with the soon-to-be-retired powerplant.


THANKS!

[puppet]

Your exhaust flow ... or lack of it is causing the creep.

What do you know about the engine and mod's done under the hood as it stands? Post what you know you have ... ECU, injectors, the whole nine. We can help then.

[zippitta]

Quote:

Originally Posted by 86ShelbyZofDoom The previous owner of my car said I needed to install a (granger?) valve on the line from the turbo to the boost solenoid..if I understood him correctly. The problem is as follows- The car can't go WOT.. if I do so, the boost hits about 8 psi and the engine starts to stutter (and subsequently refuses to rev any further) and the gauge starts fluttering rather violently between 6-10 psi. At 5-6 the engine is just fine. Mind you, though a swap is coming, its still a TI motor. And while someone's at it, since this is my first turbo Dodge (somewhat different from a Grand National and Z06), what can the TI motors handle safely boost-wise? All the car has done to it is a Mopar Stage II computer (I think it is stage II as per the dude) and a 2.5 inch exhaust. Thanks for the input!

It is like the other guy said, the grainger valve does not go in between the solenoid and the wg... this is probably what you did. You are hitting the boost cut(which is bad)....You have to block off the vacuum line from the solenoid and add another vacuum line going from the intake to the g-valve to the wg. If you have the g-valve between the solenoid and the wg, no matter how it is adjusted, it will always overboost. I had the same trouble with my car and after a month of asking, no one was able to answer that question for me. Best of luck to you and I hope that helped

[86ShelbyZofDoom]

As the car sits right now it just as the upgraded Mopar Stage II computer (I think) and an aftermarket cat-back exhaust. All else is stock to my knowledge..

Oh, and another thing.. VERY occasionally it will actually behave normally.. maybe one in ten times, and can rev up to 6000.

[turbo minivan]

Quote:

Originally Posted by my89daytona my car did the same thing, after much stress and pain in the ass, i found two problems, one being cam timing mine was one tooth off and did the same thing, reset timing belt and fixed the problem, other time i saw it was in the drive shaft for the oil pump being off a tooth, making timing permenantly off.

^i would checks the timing as suggested by this guy, then i would check the MAP sensor to be sure it dosnt have a crack or somthing in the vac/boost hose going to it (that would send a wack signal to the computer), then i would put in a new coil... this seems too simple, but in my opinion its most likely the cause (they just get old and i bet its still the origonal one right?),
then id go over the vacuum lines and make sure there all attached and propper, then id put in new plugs with about a .025 gap. my car has done this before,and did it again not long ago. a new coil fixed it once, and smaller gapped plugs fixed it last time, and making sure the timing is right will usualy surprise you... cause its often not, especialy with a "new to you" car.
good luck.
oh, and as for wondering what kind of boost these motors can handle, with the right stuff so it dosnt blow up, ive heard of guys running 38psi before. i run 30psi+ with no problems... but lots of good parts, time, and experiance is what keeps it together.