Ignition trouble..Or ???

[outlaw68]

This is gonna be a long post as to tell you what I have done and what I see and what I have tested. Along with some specs on my stuff..

3300 lb 10.5 car
Conventional head
single four
NX dual stage fogger SX2
BG 400 pump
tank up front
MSD 7AL-2
MSD 8979 programable controller

10.5 x 31 with a 4.10 gear
1.80 first

watch and listen to this VIDEO. Just before the top end the car on motor seems to LOSE power. (also lost and exhaust pipe whoops)
Second run on a 26 pill in fogger one stage.
Plugs look good
60 ft 1.24 330 3.67 660 5.39 @133

ON the BOTTLE
First car seems to GO WAY to far before it shifts almost struggles to get to 7200
drops 1600 rpm on gear change then before finish line noses over (sounds like its pulling a trailer)
Changed valve springs (no help)
Changed Battery (no help)
Changed NOS tune (no help)
Changed PLUGS and WIRES (no help)
Tried second stage...Faster but...(STILL THERE) Misses on big end now..
Took second stage off,
Changed carb (no help)

Checked voltage at box (same as at battery 13.4 volts)
EGT varies 30% on some cylinders NEVER the same cylinder (????)

Just swapped a NEW msd box... Same problem..
Have not swapped coils yet.. Thats next..


Engine leaks about 5%-6% on all cylinders hot.

Any help is appreciated..
I have a new convertor to try this weekend, but I think the problem is in the ignition somewhere.... The fact that it does it on motor and on the NOS makes me think its not in the NOS but that the NOS makes it worse.

Any help is grealty appreciated.
Thanks
Jim

Here is the VIDEO to watch and listen too.

http://www.youtube.com/watch?v=pbOcOq2sXhg

[JAMBO]

I dont know if this would help but to me I would check your grounds on your ignition, make sure they go back to the battery. That might explain why the EGT's are eratic and jumping aroundi it would also make sense why changing the box did not make a difference.Voltage at the ignition box is not near as important as the capability for the electrical system to handle current (amp) draw. As current increases voltage decreases and the box/coil would start shutting down. Anyway hope this helps, something to look at anyway. Good Luck! P.S. Thanks for input with my fogger problem.

[Jim Monson]

what about the fuel system?

[Shawn Morrell]

Sure it's not the camshaft choice?

[ramsolutions]

Make sure your crank trigger wires have a grounded shield. You may be picking up noise from your spark plug wires.

[outlaw68]

I have checked the grounds but they do not go back to the battery, They go to the frame where the engine is grounded as well. They check fine, but I have always wired my cars this way..
I also have the shielded crank trigger wires as well and its grounded. It is not however ran by itself. It is ran next to the fan and water pump wires. But the problem is the same even with the pump and fan turned off, so I ruled that out.

Shawn you bring up a good question, I also have wondered about camshaft. But I have ran similar shafts to this in the past..

[rsnova]

Hello,I'm having trouble with my BG 280.It's supposed to be set at 20 psi from the factory.I rigged my nirous flow tool with a 30 psi guage and -10 fitting and measured only 15 out of the pump.I've got a 434 and seems like it won't pull past 6500.I noticed the fuel level drop in the big float level glass @ 3000 and pressure fell from 8 to six.So I put in a Magnaflow 500 and had 25 psi at the regulator.Revved it up to 3000 and no pressure drop or level drop.Going to try it out on the 23rd to see if it will pull over 6500.SO,basically check the pressure of your BG400 and adjust the pressure.Hope this helps.I'm thinking I'm going down the track with the bowls only filled halfway.It feels like it pulls hard at the end because it has time to fill as opposed to the top of 1st and second.

[outlaw68]

I have checked the fuel PSI, thanks though and your right, I have seen it before.

I did find tonite that my crank trigger had a VERY VERY tight air gap, about .019 instead of the .050=.080 they recomend. Looks like its even touched it a few times.... MAYBE?????

[ramsolutions]

Have you put a timing light on and checked that you are pulling out timing accurately? Disconnect your solenoids and trigger each stage while the motor is running to see exactly what the timing is doing. Is your rotor phased correctly?

[Jake]

What are your plugs gapped at?

[outlaw68]

I run the AR autolite. With a cut back ground strap. No gap

[outlaw68]

Have you put a timing light on and checked that you are pulling out timing accurately? Disconnect your solenoids and trigger each stage while the motor is running to see exactly what the timing is doing. Is your rotor phased correctly?

Yes I have, it does it on motor as well. The timing is right on.

[farrigno]

i wonder if its trans or convertor related, the way it seems to lug down on the top end listening to the vid. btw dig the way your car changes color from day to night! sorry not much help.

[ramsolutions]

How old is the barry grant fuel pump? How is plumbed?
Any way of monitoring fuel pressure during a run, visual or datalogging?
Have you checked flowing pressure?

[outlaw68]

How old is the barry grant fuel pump? How is plumbed?
Any way of monitoring fuel pressure during a run, visual or datalogging?
Have you checked flowing pressure?

Brand new pump. 33 lbs at the reg. Mounted up front with fuel cell...12 line feeding it, 10 line out of it to the fuel log. BG 4 port reg on motor, 2 holley regs on fuel log for the NOS.

[ramsolutions]

Are you dead heading the pump to the regulator or do you have a return coming off each reg? Sounds like enough pump but wondering if you are getting a pressure spike if you don't have a return line.

[Tech @ BG]

The first thing you should do would be to flow test your fuel system to make sure it's doing what it's supposed to. If you take your fuel lines off of your carburetors and put them into a fuel jug, time how long it takes to flow 1 gallon of fuel. Your system should be able to do it in about 10 seconds. If it doesn't we'll want to go back through the plumbing to see if there is any type of restriction.

Have you check the voltage going to your system yet? If the problem is worse when you have the nitrous on (a lot more amps) it may be a voltage situation to either your ignition, or the fuel pump.