blower lope help

guys, my car has developed a pretty good idle lope. Gorr set my fuel system up last year and it worked great. now this season, I haven't changed anything but the torque converter and its got a bad lope. I have the idle it to about 1700 to get it to stop in gear so that is about 1900 in neutral. I was able to idle around 1500 in gear last year. The idle check and barrel valve are set exactly as they are supposed the be. 61% BV and 8# idle check.

Combo is a 540 with 871 BDS standard roots with 11:1, bird catcher hat, K vavle, 110 pump, hats and ports. PG with TC.

Gorr had me clean hat nozzle air bleed and check for blade flex (they are not) they wanted me to open air bleed hole in top of hat to let air in instead of opening blades to raise idle. It already has 3/32 holes in top of hat. I have a 4" spacer under hat with the nozzles in it, so I opened the plugs i had in the hat nozzle holes. I opened one plug and no change, then second plug just raised idle to 2000 and of course lope went away.

I have raised and lowered BV%, raised idle check to 11#...nothing has worked but idling up and I don't understand why I am having to do that now, nothing has changed.

It does idle at 1500 smooth in neutral but lopes when put it in gear, so I thought it might be TC pressure related, so I changed tranny to one that has 250# idle pressure in stead of 200#....no difference...might be worse but late last night and didn't let run long.

Talked to TCI, they didn't thick it could be converter.

Help please! Is there anything in BV or blower that could have changed causing this? Any ideas? Should I change TC?

Thanks very much for your input.

 

I would also check ignition timing and if the blower belt is too loose.

 

Does the new convertor have a lower stall? If so, I would think that it would put more load on the motor at idle and raising the idle should correct it.

If the stall is not lower then please disregard this post.

 

61% on the BV seems kinda low, try changing it to 70% give it more fuel

 

idle

Give it more fuel + check timing. then check it again. Check all pressures. Just keep trying changes one @ a time. Keep everything written down. so you know If worst comes to worst, try the old converter again. Everyone likes to tighten up the converters on blower applications.Don

 

our idel is set around what yours is..Dave

 

i had the same problem and it turned out to be too rich. try idling it gear with the brake on and lean the barrel valve till it cleans up. mine took about 5 flats but now is perfect. i only need to open up a plug or 2 at altitude. good luck

 

I would just like to comment that I've never been pleased with my repeatability of using a leakdown to set BV's. I still do it to get into the ballpark, but than adjust it on the running engine.

 

Same here.

 

Yeah just raise the Idle a little, if the new convertor is tighter it will drag the motor down a little more and make it lope. Sounds cool but don't help the performance.

 

this!! ding ding ding!! we have a winner!! (well at least i think)

bump that idle up til the thing levels off a bit... the leak % will follow it up. if you're spinning a tight converter (especially if it's a bigger one) it will probably behave better around 2,000ish give/take

i also see you mentioned that gorr set you up and you 'haven't changed anything' but you are noticing changes in the way it behaves. just because YOU didn't change anything doesn't mean things aren't changing. sounds like you a describing a really flat acting motor (at idle at least)... what % are you driving the blower. how many runs are on it from the initial set-up... maybe it's loosened itself up making the thing act a little flat?

did you notice last season that you gradually crept up in the main pill size to 'maintain' the plugs/performance/behavior? if so... re-read the paragraph above

just tossin ideas at ya... but i'd start with the idle bro... have driven converter and clutch cars and fighting a lurching converter deal is a pain in the a$$

 

thanks for the ideas, i have played with idle/BV to get it better than it was, but its still higher than I like to stage, but I quess I will get used to it. Spike Gorr said that lope comes from a rich condition, so leaning the BV is one option of course that makes me concerned about heating up the motor too much at idle. he also mentioned butterfly flex and it seems that the middle may be flexing a little while the outside are not.

any ideas on how to stop that? I tried closing down the butterflies and opening up other holes in hat and that didn't make any difference either.

blower is about 46% over. but has about 80 passes since new.

thanks

 

Bv

Do you run a radiater in this car?
When you look at the BV turn it to the left to lean it or right to richen it. I normally make a mark on the link bar so I know how far I have gone. I do'nt think you need to lean it more than a single flat, but make sure you bring it up off of idle (2200 rpm)after the adjustment for 20 sec. or so to clear the extra fuel out then let it ldle again and see if it lopes. This usually fixes your problem. You are adjusting the air / fuel mixture for the idle.

 

my guess is this