Re: U/SA help request
 

I don't discount that it could be ignition. It has a Digital seven with the MSD coil.
I am very meticulous when it comes to ignition wiring. The MSD has 8 ga wire directly to battery for power and the same to the block for primary ground. The MSD has no low voltage alarms recorded. will re check all of that. We are going out Friday and will swap boxes and coil.
I thought Mark was right and I would find a bunch in the filter or in the trans pan. But more subtle than that.

Re: U/SA help request
 

If its been sitting a while I would check the valve springs too. Might even have a broken one or two. something like that could happen between two runs. Most likely not the MSD or coil. Anything else change electrically? The digital boxes don't like any "electrical noise". Did you run a leak down or compression test?

Re: U/SA help request
 

Years ago we had a fuel pump go bad. Had pressure but no volume. Or a plugged fuel filter. It caused us a major performance loss and didn't affect the running of the car. No engine miss or nothing. Changed pump problem cured.

Re: U/SA help request
 

[QUOTE=Bob Gullett;463588]Years ago we had a fuel pump go bad. Had pressure but no volume. Or a plugged fuel filter. It caused us a major performance loss and didn't affect the running of the car. No engine miss or nothing.

I lost a class race a few years ago to Bob because of a fuel pump failure in a "U" car. fuel pump just failed to keep up because of lack of volume.

Re: U/SA help request
 

Spent about 1200.00 to find it was the pump. Had gauge mounted in front of windshield and always stayed above 6 lbs. So I chased everything else until I changed pump as someone suggested to do and shazam.

Re: U/SA help request
 

That's the only way I can beat that U car! LOL

Re: U/SA help request
 

You said you ran 8 gauge wire from ign box to power source but ground to the block,I had 2 different boxes in 2 separate cars that gave problems until I grounded box directly to the battery.might be worth a shot......Victor

Re: U/SA help request
 

a few season's ago our car slowed down 4 tenths from one race to the next. After going through all the usual stuff in the engine.trans and so on it turned out to be the rubber hose in the brake line at the rear end had collapsed and wouldn't release the brake pressure all the way. Changed the hose and car picked right back up. Might be something to look at.

Re: U/SA help request
 

Mike

That sounds weird that you could lose 4 tenths and only slow down 4 mph. How did the short times compare to the first run??

Like Bill B said check your rubber brake hoses, I've had some that would collapse and hold pressure.

Keep us posted on what you find.

Good Luck

RJ

Re: U/SA help request
 

The rest of the story. I steal the datalogger out of the SS car and we head to Wildhorse
Pass. When the car leaves the fuel pressure drops to zero and never recovers the rest
of the run. Enough fuel that the car doesn't miss.
The idea of let's not over spend on the fuel system didn't work out. I would have never thought that a 110 gph pump would not be enough for a 225 hp stocker.
So on goes the 400 gph spare for my car. Problem solved. Right back to where the et should be and the car is now consistent.
As a side note. The pro bracket cutoff here is 13.99 and here car won't run that in the heat. So I prep a 1.21 carb thinking that it will pick the car up enough to run 13.99 during the day. That carb picked the car up 6 tenths and almost 6 mph. 13.42 at 98 mph on the first pass.