Hi All,

I just purchased a 1995 Bonneville SSEi. I love the car but it has a few problems that I was hoping you guys/gals could help with.

The biggest problem is that it doesn't shift into overdrive. The transmission shifts smoothly through all the other gears.

It used to idle rough, but I put in new plugs and wires, and that seemed to fix the problem...almost. It is still a little rough from about 800-1000 rpm, but that might be only when it is warmed up. I'm going to look at it again before I go home from work.

My third question is more of just a curiosity. My boost gauge goes from -10 to +10. Most of the time the car operates in the negative range. What does it mean to have negative boost? I would think it would be positive only, but I don't know much about superchargers (obviously).

Any help would be greatly appreciated.

Thanks

whats the rpm reeding at 65mph? it should be at around 2000

Not going into OD could be a leaky vacuum line or bad TCC?? Sorry.. no expert on that.. wait till Mustafa-> Willwren or Color ME Bad -> JR3800 ( cause he'* color blind ) or any of our techie nerds chime in for that.

As for the boost thats normal.. I asked that a while ago and from what I gather is when you hit zero boost you're in same as atmospheric pressure.. most N/A cars have to create a vacuum to DRAW in air ( which equal to negative boost ) and when you're at zero the air being compressed is the same as outside air pressure and you know what boost is.. I think I"m sayin it right.. let me get back to you when I find the link of that previous discussion.

The rpm @65mph is about 2600...too high to be in overdrive.

Thanks for the info Drifter420. That makes sense about the pressure. So, basically the */C isn't doing anything until the boost goes above atmos. pressure.

As far as the TCC solenoid, that'* what I suspect too. From other posts, that seems to be a common problem. But in the other posts, everybody else seemed to be having problems coming out of overdrive, which is the opposite of my problem, so I thought maybe it could be something else.

Does anybody know how much a TCC solenoid costs? I guess I better by a shop manual, because I don't know where the TCC solenoid is or what it looks like .

You need to get a scantool on that thing first, and verify it.

If you put your location in your profile, we may be able to figure out if we have a member nearby with a scantool.

Hate to point out the obvious, but is your transmission fluid topped off??

Sounds as if your torque converter is not engaging.

Boost is normal. The supercharger does not boost unless you are accelerating. So the pressure sensor is measuring engine vacuum, which is what'* in your intake.

The more you accelerate, the more the supercharger boosts with more pressure.

OK, I'm borrowing my father in-law'* scan tool. There are no error codes in the computer. There was a loose vacuum line that I tightened, but it didn't seem to fix anything.

I scanned the computer as I was driving down the freeway and it did go into overdrive at about 48 mph. One of the codes said the TCC Slippage was 255rpm. What does that mean? The knock sensor was between 3 and 5, but the knock retard was 0 degrees. Would that have anything to do with overdrive?

The car still idles rough too, even after new plugs and wires and fixing the loose vacuum line. I'm not sure if that could be related to the problem above or not.

Thanks for any help.

I should also add that the TCC Duty Cycle was 0.0% and that the car was completely warmed up.

The TCC solonoid never said ON? And no codes? There'* another reason it'* not trying to engage then. Sounds to me like the PCM isn't telling it to engage.