Overboost

[clocktowersniper]

Ok, I have checked everything to find my over boost issue. 86 Daytona Turbo Z C/S bone stock T1. Vacuum lines check out fine, no cracks or leaks. Waste gate working fine when I put vac to it. The only thing I found was that the vac line on the purge solenoid for the wastegate was on the wrong spot. I changed it but it didn't make a difference. It had been put on the top purge post and not the bottom.
The car runs great, no smoke. But if you get on it the boost gauge pegs itself and it overboosts as it is supposed to. The problem is I cant even pass a car on the highway because it goes right to overboost.
Computer is stock, No codes set except overboost 45. Maybe the solenoid itself is bad?

Now on the second note, If I am going to end up having to change something, Maybe add a boost controller or change the cal, I might as well add some mods. What do you guys suggest while keeping it a stock looking T1?
It doesn't have to be crazy fast but I wouldn't mind being able to keep up with my suburban.
Remember it has to "look" stock, No T2 conversions.

[sdac guy]

Boost, not vacuum, is supposed to operate the wastegate.

Try connecting the wastegate line directly to a manifold port, by-passing the WG solenoid. This should limit the amount of boost to 5-6 psi (or there-abouts). If it does, only then can your WG be eliminated as a source of the problem.

If you still get overboost, then the wastegate actuator IS the problem.

Barry

[clocktowersniper]

I didn't have any extra vac lines laying around and the store is closed. What I did was I just bypassed the solenoid. The first test drive it did the same thing. Upon a closer look I found that one of the lines had a T fitting going to a one way check valve that went to nothing. I removed the T and made it go straight through as if getting direct vacuum and it limited the boost to 7-8 psi, No more over boost. So then I hooked it back to the solenoid still minus the mystery check valve that went to nothing and took it for a ride. This time the boost gauge went straight to pegged and I juts backed out of it fast because I know there isn't enough fuel for that much boost stock. So now it will peg the gauge and the computer wont shut it down.
So right now it is routed the way it is supposed to be according to the diagram on the inside of the hood, crazy boost no shutdown.
Originally had the one way valve and would go right to over boost and shut down.
When solenoid bypassed and check valve removed, 7-8 psi no over boost.

[sdac guy]

So that means the actuator is good, and the question then becomes why isn't the WG solenoid working correctly? Since there aren't any codes other than the overboost code, it probably isn't an electrical problem (electrical check is made during startup diagonostics).

So it must be dirty and it can't activate when energized. The solenoids are easy to clean or to swap out. But when removing them, care must be taken not to damage them and to document where the lines go. The solenoids come out as a pack of 4 and then can be disassembled individually. If you want to swap solenoids, I would suggest changing the WG solenoid with the one on the left end (canister purge solenoid).

When cleaning them, disassemble the solenoid and use a Q-tip and carb cleaner or WD-40 to clean the interior of the vacuum routes and the plungers.

Good luck,
Barry

[clocktowersniper]

I already cleaned the wiring connectors but didn't disassemble them. They were very clean to begin with. Is the solenoid pack still available?

[clocktowersniper]

What computer should this car have? I ran the part number and it comes up for 86 lebaron turbo auto.

[sdac guy]

I already cleaned the wiring connectors but didn't disassemble them. They were very clean to begin with. Is the solenoid pack still available?

Like I said, since they are not throwing a fault code, it is likely that there is not an electrical issue.

I don't know if the solenoid packs are still available (I don't think so).

The factory parts manual shows LM part # 5227255 for Turbo with auto trans in E,G,H, & K bodies. 5227371 is shown for Turbo w/ manual trans.

Barry

[going4speed]

Have the same problem. No boost control by the computer.

So the solenoids are able to be taken apart for cleaning? They look completely sealed?

[clocktowersniper]

I have not tried to take mine apart. There are some tabs poking through the top of the bracket. It looks like they may be able to open up.
Drove it today and no more over boost but limited to 7 psi. Oh well, I guess I don't need to go fast for now. I am more concerned with not breaking the motor.

[sdac guy]

Have the same problem. No boost control by the computer.

So the solenoids are able to be taken apart for cleaning? They look completely sealed?

Yes. I have done this in the past. They come apart fairly easily.

Barry