Griff Idle problems retrun - perfect timing!

[wadesnj]

Just to make sure I miss the Growl, my Griff decided to not idle again this morning. Exactly the same symptoms as before, will start and idle for a short time, then stalls. Starts again very reluctantly, but once revving will run fine. As long as you keep the revs above 1500 will run fine. As soon as you take you foot off, it will idle for a few seconds, then the revs dies and it stalls. I tried tweaking the base idle as suggested by Fernhurst, this seemed to help for a couple of days, but now it is back to same behaviour as before. I tested the stepper motor in dnb's Griff, and it seemed to work fine on switch on, cycling in and out as it should.

Any ideas?

Looks like I'll be Growling by Suzuki SV!

[GreenV8S]

Is it running roughly, or just idling too slow? Does the problem go away once it's warmed up?

[blitzracing]

Sound like an air leak in the plenum area. The air leak matters less as the rev's rise and the air volume goes up so it will run OK, but at tickover the lack of airflow through the MAF (caused by air getting in elsewhere due to a high vaccume) causes the ECU to reduce the injector pulse timing, so it runs so lean it stops. The restart is OK, as the injector pulse width is fixed for the first few seconds of engine running untill the MAF airflow readings take over. Check the air inlet pipe to the plenum and the various rubber pipes. I had this probem when a screw that hold the preheat plate was missing after a rebuild - took days to find just a small leak.

[blitzracing]

Being a bit vague--the air leak would have to be between the throttle plate and the engine to fit the symtom. Ie Plenum base, trumpet base, inlet manifold etc. Not the plenum inlet tube.

[dnb]

Steve, that would explain the whistling noise we heard. It's not much of a job to pull it apart and put some sealant in there...