Holley help needed

nbracken · #1 (**permalink**) 07-02-2003, 02:48 PM

Guys I need some advice on the most likely cause of a problem I am having with my car. It has a small block Chevy fitted with a Holley 600 with vacuum secondaries (model 4160) and fed by a Holley electric fuel pump (97 gph).

It has run pretty much faultlessly for 13000 km. On my way to the meet at Elvington, UK (and spookily enough just as the odometer rolled past 13000 km – though I am not superstitious…) for a few seconds the engine hesitated then lost all power. I was travelling slowly (about 50 mph on a light throttle load) – I was just about to reach for the hazard warning light and coast to a halt when the engine picked up again and started operating normally. I ran faultlessly all the way through Elvington, including runs round the track and on the drag strip.

Next occurrence was 2 weeks ago (at 15500 km) when on another club event in Germany, the same thing happened during a cruise, again on light throttle opening. Engine lost all power for a few seconds (maybe 4 or 5 seconds), then it returned to normal operation. It behaved all the way home (more than 500 kms).

I believe engine electrics are 100 pct OK and it almost feels like the engine has lost all fuel supply. So possible causes?

- Fuel pump intermittent problem – I have about 20000 km on the pump over 9 years and wouldn’t have thought this would be a problem yet.
- Blocked fuel filter? Unlikley - why is the loss so total and then it recovers and runs faultlessly again?
- Problem with the float in the Holley? I am coming to the conclusion that I have a sticking float in the primaries in the Holley. Have any of you guys come across this problem and do you agree with my diagnosis?

Appreciate any insights.

Thanks

Mr.Fixit · #2 (**permalink**) 07-02-2003, 03:08 PM

A stuck float will cause your motor to run rich, restarting it can be troublesome due to fouled plugs. Unless it is stuck "up" then no fuel will make it to the bowl. Remove needle and seat, clean or replace.

Next time it dies, turn off ign key and then remove sight plug from front fuel bowl, see if it has gas, bet it doesn't.

9 year old holley electric pump, that's a long time for those units.

Could be a clogged pick-up screen in the tank, it will get junk covering it until it can't suck gas. When pump is turned off, the debris falls off the pickup allowing it to run for a short period of time again.

You probubly don't have a carb problem, but a fuel delivery issue.

Hotfingrs · #3 (**permalink**) 07-02-2003, 04:20 PM

I'm betting on the fuel pump...might have a collapsing fuel line, but it would have to be between the pump and tank, because the pump is pushing the rest of the way....

427sharpe · #4 (**permalink**) 07-02-2003, 05:55 PM

I had a similar problem with my GT350 that started from a random annoyance to a real pain in the tail. Be driving along, and the car would die. Restart, no problem. I thought my fuel pump was dying or the 725cfm Holley was in need of a rebuild or the Motorsprt Ignition module was dying. Turned out to be the fuel filter. The element was collapsing under load!
I has installed it in-line to my electric pump by the tank to pre-filter the gas before it got to the pump. Worked fine for quite some time before the problem surfaced. Luckily, I had decided to start with the easiest and cheapest parts before going deeper, which saved me a lot of pain and suffering! Once I replaced the filter, I have had no more problems, and I keep a spare in the tool kit just in case. I would suggest you replace the filter first, and go from there.

HighPlainsDrifter · #5 (**permalink**) 07-03-2003, 01:36 PM

Hi,
The Holley fuel pump has a self regulator in the bottom of it,a spring and slide, take it apart and clean the housing ,lightly buff the slide and reinstall. The slide sticks and gives no or low fuel pressure when it gets dirty. Run fuel injector cleaner through the gas tank every so often to keep it working properly. Put fuel stabilizer in the gas tank when storing the cobra over the winter.
Perry.

Clois Harlan · #6 (**permalink**) 07-03-2003, 01:59 PM

My vote is for the fuel filter and the pickup screen. Clean the screen and throw away the fuel filter and buy another. I bet that cures it. Of course that bow tie under the hood ....My My My!

Clois

nbracken · #7 (**permalink**) 07-03-2003, 02:17 PM

Many thanks guys - this is my first post on the US site (I am a UK and German Cobra Club member - a Brit living in Germany) and really appreciate all teh advice. An intermittent fault that so far has showed up twice in 2500 kms (almost 2000 miles) is a *****. I now have a few pointers to go after. Err about the Chevy there are many over here - don't know why - its just the way it is.

My car runs on Jag running gear too, but I love it!

ulwe · #8 (**permalink**) 12-03-2003, 04:32 AM

Hi, I agree with all other answers, and want to give you one more hint what to look for. Check what you have in the tank, it could be water. Enthusiast cars arent always parked with full fueltank, and this can allow for condesing water in the tank. And the bad thing about water is, that it has higher density than petrol. So when there is enough water to reach the fuel pickup pipe, your engine will have a problem to convert to a steam engine all of a sudden!!! So, empty the tank thoroughly or add "Karburettor spirit" which will dissolve the water if its only 1 - 2 deciliters. Try it, Ive experienced this problem, for sure!!
regards, Ulf

Cal Metal · #9 (**permalink**) 12-04-2003, 08:19 AM

As a friend used to say, "Open a Carburetor Shop--and triple your ignition business".