I've heard of the carb cleaner trick many times to find intake leaks, and now I have to try it myself, since my idle bounces between 800-1200 at a rate of about once per second. Does it matter what kind I get?

Also, I asked a guy at Autozone the same question. He said screw paying for carb cleaner (I'm thinking, oh no, three whole dollars) and use water. A spray bottle set to "streaam" and not "mist," he said. He said he learned that trick from a master mechanic at whatever school he went to. Is this trick stupid?

Finally, if it is a leak, will bad things happen if I get on the turbo? It's an 87 TII.

 

yeah, you can use water bottle to check for intake leaks. You can even use a garden hose if you want. But usually, you can hear them pretty easily with a piece of tubing.

Check the grommets around the fuel injectors, all the vac hoses, etc.

Note that one can have internal leaks that are not detectable easily: I am talking about the diaphragms, in particular, inside the ACV and EGR.

Hugues -

 

propane works well also

 

Don't forget to check the BAC & TPS

 

Propane... interesting, what sort of engine behavior occurs with that? Does it smooth out because it's breathing in something that burns?

OK, BAC and TPS... check the BAC for leaks or are you talking for functionality? I don't really know how to check that thing except the resistance check in the haynes manual. What does the BAC do anyway? I know it bypasses air, but...

 

don't light a match

 

thanks I won't

 

you can also use starting fluid. the idle will junp alot when you hit the general area.

ej

 

Bleh. Sprayed some stuff around and didn't find anything, may have been spraying too conservatively. Tried both carb cleaner and starting fluid to no avail.

I've taken the air pump off to get a better shot at the manifold, but now I'm wondering whether running it without the air pump on will hurt it. I have a separate thread going with that question but thought I'd ask here too.

Also, I've read here and there about people who've taken off the intercooler to look for an intake leak. What I'm wondering is, are they running the car without the intercooler on, and if so, are they just running some tube to connect the turbo outlet to the throttle body? If not, how are they searching this way?

Incidentally, I was working on my car at night and my friend noticed that little sparks were jumping all over the plug wires. I replaced them and no more sparks. Think this could be related to my idle jumping between 1300-1600?

ALSO, I noticed that the wires going to my air bypass solenoid valve (the thing above the BAC) are frayed and nearly disconnected. Could this contribute? I don't have a clear understanding of when/how that thing operates.

thanks again

 

and yeah it's 1300-1600, not 800-1200. I was wrong in my first post. Not that it matters