Another GTV6 Fuel Pump Question

[shane wescott]

O.K. Guys

Thanks for the response to the last q.

I understand that I can put in a super fuel tank based pump or get a cheaper equiv for the gtv6 orginal one and I am away.

Now, usually when i used to start the Beast I would hear a gurgling from the tank in the rear.

Am I right to assume this is the in tank pump working.

Does everyone hear a similar sound.

If the in tank pump dies but the main pump still works, does this still mean I will have an issue.

The main thing i am trying to isolate is whether the in tank pump is shot or not.

Thanks and looking forward to seeing heaps of 116 fans tonight at Mauceri. I will be the guy in the Zender jacket.

CAtch ya

Shane

[bt46]

Shane the main pump can be herd for say a second when you turn the ignition on as the pump builds pressure in the line. It then turns off until you start the engine. The low pressure pump is always on if the ignition is on and you should be able to hear it if you put your ear near the tank. I think i ran my V6 alfetta sedan with only the high pressure pump for a short time but the pick up pump is there for a reason. Im guessing but i would say it helps the main pump and stops surging when the fuel level gets low. You can remove the fuel line at the rear of the high pressure pump and run the ignition to see if the in tank pump is working. I used to fill up my lawn mower this way.
Im also pretty sure the in tank pump only works when submerged in fluid so to test out of the car you need to have it in petrol.
Hope that helps.
Also the gurgling my be the fuel return line pumping fuel back into the tank?

[shane wescott]

Thanks Mate

I worked form home today so raced out at lunchtime, rip[ped the pump and filter out of the 75 TS, and put it in the GTV6 in a last ditch effort to get the Beast going for the 116 Workshop tonight.

Nup, no go. Not really sure why as the line to the plenum now "feels" like it has pressure in it. I sprayed some start ya bastard (very appropriately named for my car) into the the plenum by pulling off one of the small black vacuum hoses on the plenum, and it kicked but wouldn't start. It kicked a few times but still no go.

Anyway Sunday, or potentially Sat arvo is work on car time so see how I go then.

Catch ya

Shane

[pep105]

If the in tank pump dies but the main pump still works, does this still mean I will have an issue.

The main thing i am trying to isolate is whether the in tank pump is shot or not.

CAtch ya

Shane

Shane my 75TS had an issue where it would stop running after about 20-30 mins of driving. Just before it would cark it I could hear the main fuel pump whining then nothing. Sometimes it would start again after a period of time. Occasionally it would just fail to start first up as well, but this was a lot less often.

Anyways we changed the main pump thinking that was the issue, after a few days with the new pump same thing.

Turns out it was the primary pump, so changed that and the 75 was good as gold. Part of it was my fault for not knowing there was a primary pump in the tank.

[Sheldon McIntosh]

How did you go Shane?  

According to my manual, only the 75 and 90 have the submerged pump, the GTV6 doesn't.  See attached.  Maybe because the GTV6 tank is higher so can rely on gravity?

Why am I looking at the manuals at 5.40am on a Sunday morning?  Because after getting the car ready for Sandown, something in the fuel system died as I gave it a last test-drive last night, and as soon as there is some light outside I'll be chasing it down.  I have a surge tank with a pump lifting gas to that before it goes to the main pump, so could be one of two pumps/filters, failing that the double-relay.  Either of these can be fixed/worked around.  If not, I guess it's the submerged pump, in which case I'm stuffed for today.

[Sheldon McIntosh]

Not sure it was mentioned in the other thread Shane, but to check the fuel pump you can unclip the air filter cover, stick a screwdriver in to keep the AFM flap open, and then turn the ignition on, but DO NOT START.  You should hear the pump working.  If not, either the pump is faulty, or the relays are faulty.  Sorry I have no info on the relays, I've never had a problem with them.  I guess you could hook up another 12v source to the pump to check it.

I did that this morning and realised that my secondary pump (to lift to the surge-tank) was faulty, so I was able to bypass the surge tank and just run the standard set-up till I get a new pump for the surge-tank.

[VeeSix]

Yes the GTV6 and 75 3.0 boot mounted tanks definantly rely on gravity to feed the main pump, i found this out the other night when replacing all the rear hoses on my current 75 restoration!