

| Subject: | Weird bucking |
| From: | Damon Campbell |
| Date: | Thu, 29 Jan 2004 09:40:19 -0800 |
In the last couple months, i've had a noticeable low-speed driveability problem... kind of a herky-jerky bucking at very light throttles. Happens in any gear, but is more pronounced the lower a gear you are in (1st being worst, 4th being not too bad). This typically happens around 1500-2200 rpm, and kind of comes and goes during a drive through town. I've had my trusty digitool on the dash looking for any correlation, and there is nothing i can see from any of the readouts. O2 is stable, AFM doesn't really change at all, temp sensors doing their thing normally... the only thing maybe kind of weird is that i typically show a .06v ground potential difference (since i have a digijet, my pin 19 is apparently a ground reference, or something like that). This .06v is always there, though, buck or not. This has happened with two different ECUs, too. Now, i'm wondering if it could be possible that a rebuilt tranny with clearances a little loose, a specific clutch spring stiffness (actually have that uber-LUK clutch bus-depot sells), a bigger motor, etc. could all conspire to give a natural frequency at low loads and certain rpms? This bucking, once it starts, can be attenuated by either putting in the clutch, or giving it a bit of gas... If the load and rpm are just right, the bucking can build up to be quite violent. How likely is this scenario? And if not, what would some alternate theories be? The main two variables include big engine and new clutch (had same rebuilt tranny before new engine). As always, I appreciate all your thoughts on this, -Damon ===== '84 Westy (Sparky) w/2.3L WBX (wow... it actually works!) __________________________________ Do you Yahoo!? Yahoo! SiteBuilder - Free web site building tool. Try it! http://webhosting.yahoo.com/ps/sb/
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