Guest Al 260Z Posted August 2, 2003 Share Posted August 2, 2003 Go figure! Here's my latest tail of woe and frustration. Ye Ol School O Hard Knockers has been kickin my butt lately. Ye Ol 260Z got a 280degree Comp Cam last spring and a 2-1/2" mandrel exhaust in June. She runs on a pair of Weber DGV's which have been no trouble for 200k miles. Survived All-Datsun T-hill track day July 10 with flying colors. Sometime after track day, I started having more and more trouble with erratic idle and stalling (but runs fine except at idle). No amount of fiddling with carb idle settings seemed to help. Set valves, tested comp, changed plugs, checked ignition, searched high and low for vacuum leaks. After noticing that idle bog and stall was accompanied by excessive rich exhaust gas smell (gag!), I started wondering about carb needle valves. Set DGV float levels - they were a couple mm high. Checked fuel pressure - between 3.5 psi at idle to not over 4.0 psi above 1500 rpm- OK. Idle problem improved but did not disappear. So I says to myself, maybe needle tips are wore so they regulate level ok under load but don't shut off tight enough at idle. I ordered Grose Jet needle valves for DGV from Pegasus and just installed 'em this morning. The damn things don't shut off tight AT ALL at idle and engine off. When I come to a stop light, idle is good, but then deteriorates. Stalled in the middle of busy intersection, in the damn rain, pop K&N covers off, and fuel is just gushing from main jets in both barrels of both carbs. Large puddles of gas - maybe 1/2 or 1 cup - in DGV goosenecks. Wouldn't start until I undid and plugged fuel lines, cranked 'er till she finally caught, revved to purge excess fuel, shut off to reconnect fuel lines, then restarted and drove off VERY WET AND VERY PISSED OFF. Not a happy camper today at all. Had to repeat that routine again after another stall. And after last shut-off, gas was again gushing from both carbs with large puddles in the goosenecks. (Thank goodness for the goosenecks - else all that raw fuel would be washing right into the cylinders!) I'm thinking that Grose Jet = POS. Anyone else have similar experience? I thought that lots of folks had good luck with 'em? Any suggestions ??? Right now it looks like I'll make it home and put original needles back in, then see about some stock Weber DGV needles. Don't have time to fiddle with Flat-tops right now. Later, Al Quote Link to comment Share on other sites More sharing options...
TimZ Posted August 3, 2003 Share Posted August 3, 2003 I used them when I had Mikunis because at the time I thought it was the "thing to do". They worked fine for me, but I don't think that they were a noticeable improvement over the stock needle valves. Point of diagnostic order - it sounds like you were having the same problem before you installed the Grose Jets, and whatever condition was there before has just deteriorated a bit further. Maybe it isn't the needle valve/grose jets causing the problem? Sorry - I'm not a DGV expert so I can't steer you any further than that... Quote Link to comment Share on other sites More sharing options...
Guest Al 260Z Posted August 5, 2003 Share Posted August 5, 2003 Conclusion of story. Grose Jet (at least the two I got) are POS, and soon to be returned to Pegasus. Sometimes, but not usually, they will seat, seal, and regulate fuel properly at idle. Mostly they didn't seat and allowed overfill of the float chamber which then overflowed large amounts of raw gas through jets into the intake. Tim is correct, I had excess rich idle and stalling with original carb float valves. These had typical wear on old float needles: rubber tip was no longer cone-shaped but had depression ring all around in area of needle-seat contact. These would apparently not seat and regulate level properly on idle, but they never let large quantities of raw gas gush into the engine. When on two occasions the Grose Jets did seat properly, they worked like a charm, idle was steady as a rock for minutes instead of seconds, and excess rich exhaust stench was gone. So I'm pretty sure this was indeed the problem. I've heard of this happening if the needle valves come loose and allow gas past the seating threads and gasket, but I am sure this was not my problem. Floats, float pivots and float chambers appeared as good as new, so I'm not suspecting anything there. If, after I install new Weber needle valves tomorrow, I continue to have idle and/or flooding problems, I will eat my words. Until then I am convinced: Grose Jet = POS ! Caveat Z emptor ! Ya don't want no stinking raw gas lubricating your rings ! Later, Al Quote Link to comment Share on other sites More sharing options...
Guest rick458 Posted August 5, 2003 Share Posted August 5, 2003 better check your oil just to be sure your didnt get fuel past your rings $12.-15 worth of oil ic VERY cheap insurance Quote Link to comment Share on other sites More sharing options...
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