Low Boost, or is it?

[DR2]

'88 SC, bought it two months ago, JDM motor -also sc- has (so i am told) about 70k miles. Cusco pulley is the only mod under the hood.
There is an Autometer boost gauge installed and it has never read higher than 5 psi... I didn't install the gauge myself so it is technically an unknown quantity, but I feel like it could be faster, and when my friend in his SUBURBAN tried the stoplight-a-go-go with me yesterday, I barely stayed in front of him through second gear, when I got off the throttle.
I don't know a whole lot about forced induction, but if it's not the gauge, I wonder if it's something to do with the bypass valve... can anybody shed some light on this issue?

One more thing, sometimes after periods of heavy vibration (i.e. full throttle accel, heavy braking) and sometimes for no apparent reason something in my throttle linkage is overcentering and the pedal gets very much stuck in the "off" position. I had hoped it was a lubrication issue, but that didn't help and after searching i haven't found a source for the problem. Any input on that would certainly be appreciated.

P.S. I'm sure by now you've noticed the irony of my moniker, as I know a lot about the car in general (history, whatnot), but having an open wheel background many of the specifics (everything important) I still need to learn

[Jackstand Queen]

5 PSI, wow sounds like my car a couple of days ago when I had my new Bosh Air By Pass valve with the wrong vacuum line controls setup. S L O W.

I think that your description of the slowness of your car voids the diagnosis of a leaking boost gauge line.

Most likely you have a loose SC pulley belt. When you thumb press on your belt between pulleys, you shouldn't be able to deflect it from straight very much. Maybe a half inch would be close to correct tension.

The other common problem is leaking SC intake plumbing. A hole in the intercooler, or tubes leading to and from. Clogged air filter. Shrunken gaskets at the bottom of the fuel injectors happens too.

Straighten your SC boost pressure problem out, and you're friend's suburban will be just a small speck in your rear view mirror.

[Juiced N Blown]

i would guess a charge pipe came off or has a hole in it.

[mr2tim]

Originally Posted by DR2

'88 SC, bought it two months ago, JDM motor -also sc- has (so i am told) about 70k miles. Cusco pulley is the only mod under the hood.
There is an Autometer boost gauge installed and it has never read higher than 5 psi... I didn't install the gauge myself so it is technically an unknown quantity, but I feel like it could be faster, and when my friend in his SUBURBAN tried the stoplight-a-go-go with me yesterday, I barely stayed in front of him through second gear, when I got off the throttle.
I don't know a whole lot about forced induction, but if it's not the gauge, I wonder if it's something to do with the bypass valve... can anybody shed some light on this issue?

One more thing, sometimes after periods of heavy vibration (i.e. full throttle accel, heavy braking) and sometimes for no apparent reason something in my throttle linkage is overcentering and the pedal gets very much stuck in the "off" position. I had hoped it was a lubrication issue, but that didn't help and after searching i haven't found a source for the problem. Any input on that would certainly be appreciated.

P.S. I'm sure by now you've noticed the irony of my moniker, as I know a lot about the car in general (history, whatnot), but having an open wheel background many of the specifics (everything important) I still need to learn

[328FTW]

I had a sticking throttle once and it turned out that the return screw was missing so the throttle flap was jamming in the intake, a new screw and it was all better. And I agree that your not boosting right cause it should haul better than that check all the intake pipes to make sure they are tight and then look into the ABV being iffy.

[mr2tim]

Yo mon, you should have blown the the doors off this piece of junk? Whatz up here?

Let's get together and and find out what's not right with your ride!

As a fellow mr2 owner I'm embarassed for ya, and I won't put up this this crap!

Write me in the PM mode and we'll fix this situation!!!!!!

Supercharzed Toyz
A Toyota Race Team since 1989
(mr2tim)






QUOTE=DR2;376437]'88 SC, bought it two months ago, JDM motor -also sc- has (so i am told) about 70k miles. Cusco pulley is the only mod under the hood.
There is an Autometer boost gauge installed and it has never read higher than 5 psi... I didn't install the gauge myself so it is technically an unknown quantity, but I feel like it could be faster, and when my friend in his SUBURBAN tried the stoplight-a-go-go with me yesterday, I barely stayed in front of him through second gear, when I got off the throttle.
I don't know a whole lot about forced induction, but if it's not the gauge, I wonder if it's something to do with the bypass valve... can anybody shed some light on this issue?

One more thing, sometimes after periods of heavy vibration (i.e. full throttle accel, heavy braking) and sometimes for no apparent reason something in my throttle linkage is overcentering and the pedal gets very much stuck in the "off" position. I had hoped it was a lubrication issue, but that didn't help and after searching i haven't found a source for the problem. Any input on that would certainly be appreciated.

P.S. I'm sure by now you've noticed the irony of my moniker, as I know a lot about the car in general (history, whatnot), but having an open wheel background many of the specifics (everything important) I still need to learn[/quote]