Erratic boost and rough idle

[Weazel]

Hello. I recently removed my intercooler and cleaned it. Did it ever need it! Before reinstalling it I wanted to take the boost down a few notches, just incase I got more boost to the engine with a cleaner IC. I have really fine thread pitch on my wastegate, and to be honest, I'd never adjusted it before (I always ran 18psi). I took it down about ten turns, figuring this would drop 5 psi or so (I know 1 turn per 1 psi is typical, but this one seems to be finer threaded.) There was VERY little tension on the wastegate puck when I hooked her back up. Okay, time to light it off...
It idled like I unplugged a couple plugs. Really slow, really erratic, and really rough. Usually the car idles fast, but it was on the verge of stalling here. I think maybe I took too much out've the wastegate. So I tightened it a little. It ran a little more smoothly. The SERVICE ENGINE light was on, and it topped out boost at like 11 psi. So I tightened it a lot more, little TOO much. Next run, 15 psi, and the S.E. light is still on. Right before I got home the SE light went out. Cool, so I took her for a high-boost run down the street. The needle shot to 20 psi in NO time, and I got out of it.
So, loosened up the wastegate some (like 5 turns) and ran again. The boost went to 19psi, then quickly dropped to 16ish, then flickered between 16 and 17. Really erratic.
I was wondering if that 20 psi accident hosed anything up? What would cause the boost to be so erratic? Knock retard? Did I hose up the wastegate (the rod connecting to the "can" was turned a couple times accidently)? Would the clean intercooler play a role in all this? Thanks a LOT!!

Whoa, sorry for the LOOONG post. BTW I ran O2 safe fuel injector cleaner through the intercooler (FOUR bottles), poured it out, then filled it with water and let it sit. I THINK it was very dry when it went back in. I run 93 octane with that 104+ octane boost stuff. Thanks!

 

[Weazel]

strange...

Okay, the car is now running steady at 15 lbs of boost, after lengthening the wastegate a little bit more. The tempramental Service Engine light is gone. But I'm still wondering if I could've done any damage back there. I'll have to give it a few more runs, and see if the problem has HOPEfully disappeared.

 

[Steve Wood]

Probably not....but what code was the check engine lite throwing?

 

[Chuck Leeper]

OCTANE BOOOOSSSSTTTER??

A suggestion on the octane booster... DON'T! That stuff does nothing more than crud up your plugs and O2 sensor.
They use ads bordering on fraud. They say gain 4 points of octane.. Yep. That's .4, as in: 93 octane now becomes 93.4.. NOT 97!!
When you download the engine fault code we'll be able to tell more...
Need more boost w/ No-led?/ Try to add some xylene. Or better yet, add an SMC alky kit and run 22psi on the street and use no-led prem.

 

[Weazel]

Thanks for the advice guys, consider the octane booster HISTORY. As for reading the codes, I've got a question. How?
I've done searches here, and I checked out http://www.gnttype.org/maint/malf.html
It seems idiot proof. But I'm an ÜBERidiot with these cars for now. Is ALL I need to do this a jumper? (Paper clip or short wire?) I turned the ignition to "ON" with the engine NOT running jumped "B" to "A", and the SES light blinked once, went out for half a second, and blinked on again. It stayed on. I don't know if I lost the code or what. The car does seem to be running well now.
Ugh, any help with the "poor man's" way of checking a code would be appreciated. Chiltons says I have to turn the car ON (haven't yet) but I trust GNTType more. I will soon have a scantool, once Mr. Mosher finds out if Turbolink 3.0 will work on a 486-80. But until then I have to go the cheap route. Thanks!

 

[Steve Wood]

sounds like you were doing it right...key on, engine NOT running..jumper the top right two connectors with a paper clip or such.

It will blink once and then two quick blinks....that is a 12. that is normal. It will do this 12 three times, then, if there are any trouble codes stored, it will repeat each one three times in similar manner. When it is finished, it will repeat the 12 three times and go thru the codes again. To erase codes, unplug the orange wire by the battery for a second.