Ok issue that started this year. Been to one race and two TnT. Hits good moves maybe 10 feet unloads then spins then just as quick hooks and runs fine. Going to track today and work on it before race. It has done this with different jets, timing. Last night at TNT my fuel pump wouldn't run in lanes wiggled wires that went into pump and it started running again. It's hard for me to believe that it would shut off and back on the same every time but maybe. I made 2 runs figured it would run a 5.25 ran a 5.249 change lanes shock settings drop a half pound of air guess a 5.24 it runs a 5.237 so what ever is happening is consistent. It shuts of then back on. I have several ideas but just thought maybe someone had something new. I'm going to change out pump today if I can find a replacement have a bg400 on old car and think fittings with interchange. I first thought suspension but watched a video and saw it act like shut down then hit to spin and back to hook. Thanks for any responses.

If fuel pump was to disconnect during launch and connect back quick after initial hit does anyone think this is possible and do it consistently. I didn't mention I checked 4-link, shocks and this setup was good last season. Whatever I do this morning to try and fix it I'm married to as this is first race at home track and am 13 rounds behind. Thanks for anyone's time.

If it's a sharp on and off...its not fuel. I would look at electrical problems, possibility even the master shut off switch.

Thanks Jerry. Anything is possible. The consistently doing it is what has me baffled.

Jeff,

Do you have a relay on the fuel pump? Maybe something to do with the relay. That's why I like my belt drive fuel pump.

BTW, did Efrin give you your boxes?

Unless this is EFI I don't think a quick on/off of the fuel pump is going to cause that. Do you have a fuel pressure gauge and access to a go pro? If you can wiggle wires and cause the fuel pump to come back on you have wiring work to do.
Is the motor actually stumbling or cutting out or is it all suspension unload?

Vern thanks no I will see Erin today.

Eman it's gas. Just a fast drop and go. hard to explain. It may be a simple as a float bowl adjustment. Been looking in wrong place I'm sure. The pump wire is a problem but don't think that's it because it wouldn't be so consistent doing that. Heading to track now to go over all I can. Wish me Luck and thanks for the replys. Oh and Eman are you a mean guy my auto correct changed Eman to mean. HaHa

quote:

Originally posted by Jerry Kathe:
If it's a sharp on and off...its not fuel. I would look at electrical problems, possibility even the master shut off switch.

Check that and ignition switch.

If using a crank trigger make sure it’s not loose (mounting bracket also) and adjust to .065 gap.

If you have Grid look at the Ignition IN + OUT pulses in the Data Acquisition.

Sounds like two separate issues.....
One is chassis-related, launches, spins, then hooks again.
The other is engine-related.

It's not fuel delivery. The pump could shut off on the launch and the bowls would still have enough to make it to the top of first gear or just after the shift. It's most likely electrical. Although I did see a converter do that with a slipping sprag.

quote:

Originally posted by botmbulb:
It's not fuel delivery. The pump could shut off on the launch and the bowls would still have enough to make it to the top of first gear or just after the shift. It's most likely electrical. Although I did see a converter do that with a slipping sprag.

I don’t see any way he’s making it that far on just the fuel in the bowls, not at that kind of ET he’s running.
I would guess the spin is due to lose of power then being hit with power again. Upsetting your setup.

If fuel how about jet extensions or slosh out of bowl vents. My car hesitates without the hose between the bowl vents

Thanks guys figured it out sort of. It hits lose g- force then back on. Should have left it that way real consistent for some crazy reason. This is what I found. Float level was at the top of sight glass. Ended up putting new float in rear even though it didn't need it. Had to screw needle and seat all the way level with gasket. Fuel bottom of sight glass. 6 1/2 pounds going to lanes 6 1/2 at back of lanes. Get pulled 5 pounds pulling out. Next past check 7 lbs next pass 6 3/4 next 7 next 9 next 9 lose with .4993 red. Car leaves clean after screwed needle and seats all the way down during theses passes. Next morning 9 lbs then in lanes get pulled 5 lbs for 3 passes then not sure but car was slow by .013 lose to dead 5. I'm leaning toward something in the return to tank line adjustment. To clear things this is pump and reg that was on car in my trailer fire last year. But ran last half with these with no problem. Just started this year. I put a new diaphragm in reg. and took pump off to see if vane were all working in and out as should.frustrating but got to see friends and visit so not a total loss. I sure thought it was a spin instead of a loss of power. This car needs all the rest replaced that I havnt already but just about spent out. Items I have not replaced. Ignitio- fuel pump- regulator- distributor- crank trigger pick-up and carb. Thanks for everyone's time and I apologize for it being so long.

I’ll call ya tomorrow.

Ok Vern talk to you tomorrow