Herky Jerky Weber
 

I have a weber 45 DCOE that is running pretty good except for when I am just cruising along regardless of what gear or RPM. I am idling good, have strong power when I get on the gas, and don't really fade much in the high RPMs. Just really lean when cruising. It bucks and stumbles like crazy! Can anyone tell me which set up jets could correct this? I am thinking idle jets???

Thanks

Hehe... I just got done dealing with this exact problem, same symptoms, that had been driving me crazy for quite a while. You know what it was? My idle jets were way too rich. I was using 65F9s, which is what everyone recommends, but I switched to some 40F9s that I had laying around and it fixed it. I still have a stumble at the idle-main transition that I haven't tracked down, though.

HMM idle jets too rich eh. I was going to go try the 60F9. I have no idea what I have in there as the numbers are worn off. I guess it is time to play. I just wish there was a place in town that I could just go to and play around with jets instead of buying them, waiting for them to come in the mail, and then being the wrong size.

i would try some 55 f9 idle jets
or you could stop by the shop and just start trying jets. i have a huge box of every weber jet imaginable :) i would be a long drive for you tho since im in cali.

check the acc pump bypass jet in the bottom of the float bowl. it should be a zero , another way of knowing its a zero is there will not be any bleed hole on the side of the jet. if it is a zero try larger acc pump squirters, that should fix your problem :)

So is F9 definately the right size air bleed for our cars? Is this what everyone runs? Should I only play around with the different size numbers.... 40, 50,60 etc?

exactly
also, for fine tuning they are available in every 5 thou. meaning 40, 45, 50, 55, 60, 65, well you get the drift :)

Interesting. I was wondering what that was, but I couldn't find it in any of my Weber manuals. Thanks, I'll check it out.

I do know I need to go up a size or two in accel. pump jets.

[QUOTE=PercentSevenC;8558495]Interesting. I was wondering what that was, but I couldn't find it in any of my Weber manuals. Thanks, I'll check it out.

QUOTE]


thats why im here to help !! :)

I don't know how you're running 40f9's in my stock porte4d 13b car I had the 45 on it would lean all the way off the guage when I ran 50F9's. i think yuour 65f9's weren't actually 65f9's. I've posted before on teh inaccuracies of jets out there. i had "65F9"'s that were closer to 80 with a flute hole way too big!!

that does happen alot believe it or not..
there was a batch of china copys of weber jets that got out to the public that were disgusting.
i pay a bit more for my weber products but at least i know they are genuine .

I literally have 4 pairs of 65F9's sitting here in my jet box and every one of them has a different flute hole size.

All I know is I'm running 40F9s and it feels great except for the transition and a weak accel. pump shot. When I switched to F7 e-tubes I started having the over-rich jerkiness again, but not as bad as with the 65F9s and F11s. This is with a fuel pressure just a hair under the 3 PSI mark. I need to get an AFR gauge and some other jets to try, but for now school is preventing me from having any spare money.

crank the fuel pressure up to 4.5, you're too low. Rich causes surges not stutters. when i heard your car it sounded like lean shutters on the transition to me.

Webers are very picky. Mine did the same thing. It was just always getting entirely too much fuel. It ran great when I was hitting full throttle constantly though. It wanted to richen up and stall out when idling under 1500 RPM too.