V8 Fuel problems.

[DaveS3]

Guys,

Ive been having problems in my 3.5lt V8 stage 1 over the past few months. It is VERY intermitant and usually only happens when driving very hard or flat out for longer periods of time.

Started happening about 4 months ago, and has only happend a few times since, but the car became undriveable after a trip a few weeks ago due to this problem

Symptons are - when holding high revs (2800+) for prolonged periods of time, it seems to feel as it is governed and wont rev over 3200, then basically becomes worse to a point where it feels it drops cyclinders then will not drive under load. It will still rev in neutral/clutch in.
Sometimes it fixes itself but last trip it continued to become worse to the point it would only drive to 1500revs and then try to stall. Seemed like extreme fuel starvation.

I trailered it home, leaving for a few days, but I have been driving around all week without a problem?

Theorys have been fuel pump getting hot vapourising fuel, the coil inside the fuel pump ( :? not sure here) expanding and the pump then not pumping fuel?

Any other ideas?

PS Car has bosch elect ignition and coil (will tend to work or be dead so i've been told - so i don't believ its a spark problem)

Dave.

[PhilipA]

A stage 1 is horribly complex , so you will have to get the CDrom manual and a number of electronic measuring devices. NOT.

You appear to have fuel starvation.
New filter
clean the filter in the bottom of the Facet
maybe lag the fuel pipe in the engine bay
check that the fuel cap is venting properly
Facets usually work or don't , needing a stiff kick to start ticking again.

Regards Philip A

[DEFENDERZOOK]

<span style="color:blue">hook up a fuel guage under the bonnet and run the guage up to the wiper
so you can see it as you drive.....


then drive it and see if you are running out of fuel pressure at high revs or not....


that would be the quickest and cheapest option of diagnosis....



if your pressure drops at high revs but is ok down at low revs....
it could be a simple blocked filter...or a fuel pump....

start there and let us know the results....
if fuel is ok....then we start to check the ignition sysytem....</span>

[igould]

Originally posted by DEFENDERZOOK
[color=blue]hook up a fuel guage under the bonnet and run the guage up to the wiper
so you can see it as you drive.....

Sounds like a recipe for self-hypnosis if it's raining! :roll:

[DaveS3]

We put refilled/made sure there was fluid in the carbs and checked the diaphrams and they were both good.
I bought an autometer fuel pressure gauge off a mate (new $20 https://www.aulro.com/afvb/ ) so i'll fit that and see what happens.

Thanks for the replys.
Dave

[DEFENDERZOOK]

<span style="color:blue">carbys......?
i was thinking injected...... :oops:


could simply be the float levels not right....
it wont let the needle drop enough to let the fuel into the bowl fast enough....
when you are on fast throttle...once you use up whats in the carby...
it could simply not be getting the fuel in fast enough....

ok below 2500rpm.......though.....but anything above.......</span>

[joe]

People allways overlook the simple stuff first.
Have a look at the vacuum advance unit on the side of the dizzy , the diaphram can get ripped or weak after years of use and is the most common cause of engine faults in most of the cars I have worked on over the years.
Take the small pipe off the carbie , put the end in your gob and suck , if it is stuffed you will get no resistance , to be sure take of the dizzy cap and watch the base plate , if it moves when you suck it's ok if not it's stuffed.
and all you dirty mined buggers get out of the gutter :roll: .

Hope this helps mate :wink: .

[Bradtot]

I had a bug stuck in one of my fuel lines to the carby once. It only got worse the faster I went. The landy mechanic I saw could not stop laughing when he told me what was wrong. It happened when I reconned the motor and had the carbs off to do so. Bloody thing crawled inside the tube and died. Due to the motor being new I thought it was a prob with new motor.
It would run ok until u wanted speed then would not go until u slowed down.
Never mind we all learn from these little hassles
I can laugh now but it was a pain then
Brad
https://www.aulro.com/afvb/

[LandyAndy]

Hi Dave
Have you checked the pick up in the tank??????,its the first place to check for fuel starving.If it aint coming out of the tank fast enough,everything else downstream can be mistakenly blamed.
Goodluck
Andrew

[DaveS3]

Thanks,

Im going to drain the tank again (have done it before and found a glob of silicon gasket floating around inside being picket up at the fuel outlet)

I'll try the vacuum advance think and check the hoses ect

It just has me puzzled as it is very intermitant. All week it has been fine :?

[DEFENDERZOOK]

<span style="color:blue">i assume the fuel is ok....?
no water in it?



and have you tried removing the fuel cap to see if the problem is still there...?
it may have a simple vapour lock.....</span>