Replies to post #1471 on Cars, etc. (GEARHEAD)

[OldAIMGuy]

Hi Bob, Thanks for the note on the SHO. Am happy it's back to smokin' tires. The intermittant problem with ignition is still one of the most challenging to diagnose.

Once on a Dodge van we hunted and hunted for a peculiarity of ignition. As about the last resort we checked the magnetic crank position sensor. It was covered with a bunch of tiny ferrous metal "dust." Apparently a 100K miles and lots of use of the starter had thrown off a bit of this fuzz and it had collected on it. Sort of like one of those games we played with when we were kids with a magnet and iron filings to make mustaches and eyebrows on a face. Apparently it was enough to throw off the position sensor's reading and give us a mis-fire.

That's a generous offer for a turn or two in the SHO. I'll check the schedule and see what's up. I always like to add a new track to my resume'.

Best regards, Tom

[Bob Zumbrunnen]

Found out it wasn't me and re-learning the car that was causing the problem with having to give it too many revs to launch it.

Spent some quality time with it last night and noticed the intake runner solenoids still weren't moving. Pulled the vacuum line that feeds them and no vacuum. Revved it and still no vacuum.

Doh! The vacuum is controlled by a switch I didn't get plugged back in. Plugged it in, got vacuum immediately, hooked up the vacuum line, and the solenoids moved.

Apparently their "default" position (no vacuum) is to use the high-speed runners. Goosed the throttle a few times and they opened and closed like they should.

Also removed the intake silencer. That was *not* a fun job. But got it done and it sounds really nice. Sounds like about 5 more horses. <g> K&N next.

The test drive confirmed that the problem with killing it on launches was the runner control solenoids. Plenty of torque right at idle now.

Might still have a cooling-system problem, though. I noticed last night that the upper radiator hose was scrunched up from being under vacuum. As I was removing the radiator cap, it hissed as the hose slowly refilled with air.

This morning I made sure the cooling system was completely full of water, but doubt this'll solve the problem. The middle of that hose is much higher than any other part of the cooling system and it looks like it's going to be a real challenge to bleed the air out of the system.

Still planning on taking this car to Topeka (a lot cheaper than buying tires and brakes for the Mustang), but might just go ahead and trailer it up there to be on the safe side. Don't quite trust it yet.