So this evening I'm offroadin round some local tracks/green lanes. I get to this dead steep one I've done plenty of times before. But this time i decide to slowly crawl up it, and no problems, i have plenty of grip with my newish 32" BFG MTs - (just rubbing it in )

I stopped on the top of the hill, not quite flat/level yet (big mistake), and the engine cuts out as if i've stalled! After a few start attempts, it just stops starting/firing altogether. On a solo mission, I had no choice other than to roll this 50feet steep climb backwards trying to control my speed without an engine. Anyway - I'm still alive along with my passengers, but even with the zuki on level ground again at the bottom it wouldn't start.
I had to push it to a steep downward section, to (presumably) get the fuel to my engine!

This has happened before when i've paused on a steep climb or trying to get out of a large hole. I have to roll or tow it level or downward to get it firing again.

Whats wrong?

I have a fuel pump on the fuel line in my engine bay, this was an add-on when a garage changed my engine for me, they said it needed a bit more pull to get the fuel into the engine. Is this the problem?

It feels like gravity is stopping my fuel getting through!? But i thought the fuel line was in like a vacumn, so gravity shouldn't have anything to do with it surely!?

What about my carb (standard 8v) does this work properly with my zuki at arkward positions?

What can i do to fix this? This is an problem thats slowly getting worse with time, i used to drive up this steep climbs with the same settup before!

Thanks in advance for any advice! Keep on Zukin'!

i was having this problem w/my weber.
on steep climb only, it would flood and die.
had to make float adjustments (and mount carb. "backwards") to fix.
fuel was flowing into venturi, flooding out engine.
maybe something similar is happening, like float too high?
just a thought- and maybe wrong in your case.
richard

I have had similar problems with two vehicles.  Back in the dark ages, my first car had an aftermarket electric fuel pump, mounted on the firewall.  I was told it was mounted too high, it was designed to push the gas to the carb, not pull the gas from the tank.  Since I didn't run it offroad, I didn't worry about it, but sometimes the engine seemed to be starved for fuel.

The second vehicle had the OEM carburetor mounted so the float pivot was in the wrong direction.  When I tried to climb a steep hill the carb would flood out the engine.  The fix was to lower the float below the specs.  I'd be inclined to doubt that is your problem, since I understand your carb is stock.

When you figure it out, let us know.  I'm curious.

Just to state the obvious, as I'm wont to do, your tank wasn't getting near empty, with the fuel simply sloshed away from the pick-up, right?

I have a fuel pump on the fuel line in my engine bay, this was an add-on when a garage changed my engine for me, they said it needed a bit more pull to get the fuel into the engine.

I don't know what they are talking about, there shouldn't be a problem with the stock pump. Sometimes with an engine change the pump needs to be primed, possibly your fuel pump diaphram (sp) was starting to go. Is the stock pump still plumbed in line?
I would start by sorting out the stock pump and ditching the leccy one. Change the filter too it could be partially blocked.

When it stalls out and dies like that on a steep hill climb, you can hold the throttle wide open and crank the engine over until it fires. It may be a little sputtery but a few good revs should clear it out.

Amilla

Just to state the obvious, as I'm wont to do, your tank wasn't getting near empty, with the fuel simply sloshed away from the pick-up, right?

Wouldn't have thought so... i had a good half a tanks worth

Quote from: skandy32 on March 20, 2008, 06:29:39 PM

I have a fuel pump on the fuel line in my engine bay, this was an add-on when a garage changed my engine for me, they said it needed a bit more pull to get the fuel into the engine.

I don't know what they are talking about, there shouldn't be a problem with the stock pump. Sometimes with an engine change the pump needs to be primed, possibly your fuel pump diaphram (sp) was starting to go. Is the stock pump still plumbed in line?
I would start by sorting out the stock pump and ditching the leccy one. Change the filter too it could be partially blocked.

As far as i know its an electric fuel pump. With the engine change years ago there was something to do with mixing and matching two slightly different 8v engines together.

I wondered if perhaps the fuel lines / filter was deteriarating...

When it stalls out and dies like that on a steep hill climb, you can hold the throttle wide open and crank the engine over until it fires. It may be a little sputtery but a few good revs should clear it out.

Amilla

...Nope, didn't work im afraid. I tried a handful of things to try and start the engine before rolling the hill backwards!

I had a new Ford about 40 years ago that acted like that once when I was racing from a stop light .  The problem turned out to be a partially clogged filter at the inlet of the carburetor.  This filter was a fine screen in the inlet of the carb, not the regular in-line fuel filter.  The car would run fine for normal driving, but would not supply enough fuel for high demands.  I don't know whether the zuke carbs have such a filter.  Maybe your regular filter just needs replacing.

My 2¢.
Looking at the particulars of the situation, I suspect the fuel pump or the supply line position in the tank. You state that the pump is in the engine bay. That's about six feet from the tank with an elevation of about 6" above the tank (for illustration).
Now you climb a steep hill and raise the front end of the vehicle. Now your pump is, say, two feet above the tank.
If your pump is getting weak, and they can, it probably couldn't pull the fuel.
I wouldn't think it would have lost prime, as you stated you had a half tank, but don't rule it out. Who knows where the filter/inlet sits in the tank after the shop modified.
When you started downhill the pump would be lower than the tank, thus getting help from gravity, and possibly priming the pump.
This scenario makes sense to me based on your account of the events.