<VV> 110 Engine Dies at Highway Speeds

[Bill H.]

                                                                                                              B”H

 

Hi all, I hope everyone has a happy and successful New Year!  

I have a problem upon which I hope perhaps one of our Vair Expertsmight be able to shed some light.

My car is a 1966 Monza Sport Sedan, with a 110 andPowerglide and factory A/C.  The ignitionis a CraneCams XR700 and she has a Clark’s-sold electric fuel pump along with aHolley fuel pressure regulator which sets the fuel pressure at around 3 psi goinginto the carbs.  The pump is(was) protected bya Revolution Electronics controller that sends power to the fuel pump only witha tach signal.  I fitted an “OK” indicatorlight to show that 12v was being fed to the pump from the fuse box.  The pump is mounted on the frame rail next tothe fuel tank.  The fuel pump (andfilter) is brand new, I replaced it about a month ago.

Up until a few months ago, I had the car running as good as brandnew.  She idled nice and smoothly and couldcruise up to 70 and beyond (if I pushed her which, which I don’t. I usuallydrive between 55-65 on the highway).  Shehandles like a dream with good tires, heavy duty shocks, and bushings, etc. allkept in good condition.

For short distances (less than 50 miles), no problems.  Even if I start the engine after sitting fora couple of weeks, she fires up on the first try.

What happened was that about 2 months ago on a 100 mile roundtrip to my Mom’s(she lives 50 miles away in Monsey, NY), she drove great.  Just before I reached Mom’s, I felt s “skip”in the engine but it was negligible.

On the way back, I got about 30 miles toward home when allof a sudden the TEMP-PRESS and GEN-FAN warning lights went on, and the engine just died.  I coasted off the highway, tried to re-starther.  The green indicator showed that thepump controller was not feeding 12V to the pump, so as an emergency measure I bypassedthe controller to an on-off switch (but kept the tach wire connected to thecontroller). Voltage was back to the pump and the ”OK” light went back on.  She cranked, the fuel pump was buzzing, but shewouldn’t fire.  I waited about 5-10minutes, tried again, she fired up instantly, I got back on the highway and shedrove like nothing was wrong.

10 miles later, same thing. Had to coast off the expressway, had to wait about 5-10 minutes, thenshe started and we were back on the way. 5 miles later, same thing.  2miles after that, same thing.  It gotworse and worse and eventually I got her off the parkway.  From there on local streets, she drove likeabsolutely nothing was wrong.  Since thenI haven’t been on the highway with the Monza, but in local traffic she drivesperfectly.

The above (trip to Mom’s) scenario happened twice, exactlythe same each time.  I’m now afraid todrive her any distance until I can isolate the problem.

Yes, I am aware that I have to add a fuel pump shutoff, butI want to isolate this problem first.

I suspect:

1.      Fuel pressure regulator?  Maybe 3 psi isn’t enough to keep the enginefueled at 2500-3000 rpm at highway speeds 

2.      Ignition? Could the electronic ignition fail at high RPMs but work fine at lowRPMS?

Any suggestions would be greatly appreciated! 

Thanks everyone…Bill Hershkowitz