VS New Fuel Pump Intermittent Failure

[RUN415]

Hi All,
I have a 1995 VS Exec Dual Fuel...had a few fuel hiccups so I installed a new GOSS fuel pump which works for a bit then fails to prime.
On two occasions it failed to prime soon after I topped up the fuel to protect the pump.
Second time it failed I drained the fuel (as per normal replacement procedure) and it primed...
so I drove it on LPG for a bit then it wouldn't prime again...still had fuel but I didn't add any as a test.

The wires going to the tank look ok and there's power at the plug which joins to the actual fuel pump.
I took the new pump out today and put the old one back in to try and find out what's going on.
Both pumps tested ok (primed wet) out of the tank and the old pump primed up once re-installed.
I have to drive 100 k's tomorrow (live in country) mostly on LPG but that should be a good test...
...but I'm not feeling too confident and I have no friends out here who can help or tow me if I get stranded.
The car won't COLD start on LPG for some reason but will if it's warmish so I should be okay if the pump fails again.
But that's a pretty big SHOULD and leaves me in an unpleasant, stressful situation 'coz I can't afford to get stranded...and it's doing my head in.

I also checked the error codes today...and got...
35 - Idle Speed error - [Not sure what caused/logged this]
42 - Electronic Spark Timing Bypass Circuit fault (EST) - [This is probably caused by my battery which is/was in poor condition - borrowed a good one and it now cranks over for ages)

I thought the bad battery may be the cause of the fuel pump problem but I no longer think so after using the better one.
Maybe I'm not installing the pump right or it's sucking up crud from the bottom of the tank and fouling the pump???

SO...
1) Any ideas/advice would be greatly appreciated.
2) Also, any hints on COLD starting on LPG would be helpful - I tried counting to 4...on /off and variations as suggested elsewhere on the forums but it didn't help.
3) Just curious - Is it likely that the fuel pump runs all the time or cuts out when LPG is activated???

Thanks in advance...I will post back tomorrow...if I make it back home

[hako]

I know zero about LPG, but I'd figure the pump would NOT run when in LPG...and the injectors would also be OFF. This should happen when you switch to LPG - so maybe the changeover switch is faulty and not always switching the fuel pump back into circuit when to switch to petrol.
You could just run a hot (and fused) wire to the pump with an on/off switch just so you don't get stranded.....think it's the purple wire at the pump that is hot but double check that.
In the Gregory manual there is a bit of data about when the pump switches in and primes when you start....maybe that would be of use?

[RUN415]

Thanks for the reply Hako...muchly appreciated.
Could be the switch...I'll check again for power at the pump next time it fails.
Last time there was power at one of the 4 pins that connects to the outer pump assembly.
Yeah, a manual would be handy...have to get one...but just so broke at the moment.

I didn't drive into Gambo today...just puttered up to the servo (10 k's away)...with some degree of trepidation. :-)
Car ran fine and I started it a few times after adding more petrol.
Only has a quarter of a tank at the mo...probably should add 20 litres to totally cover the swirl pot but I already have
15 litres of dirty unleaded hanging around the shed that will probably end up going thru the mower. (After a quick filter
Dam these in tank fuel pumps...absolutely hate 'em!
One good thing....it took me about 2 hours (or more) to do the first pump changeover...can do it in about 30 mins now :-) and it's nice to know what's going on down there...
...although I'm not so sure I enjoy getting so intimate with my rear axle :-)

Anyway, checked the codes again...after battery disconnect,
(was more careful this time...yesterday I inadvertently (clumsily) shorted out my parkers + inst panel and had to replace a fuse...such an idiot!)
12 12 12 - Just got 12's so that was kinda good...yip!

So if this old pump hangs in there for a while...it means the new GOSS one is shite or I damaged it putting it in.
I bort it 6 months ago too...so not much chance of a refund...was $100 with the new filter.
Anyway, time will tell and I will post back with the outcome...or more failures. (fingers crossed)
It's times like this I wish I had my ol' gutless, inefficient and uncomfortable EH wagon...
...at least you didn't need a science degree and robotic arms to work on the thing. :^)

Thanks again Hako...good luck.

[hako]

Last time there was power at one of the 4 pins that connects to the outer pump assembly.
Yeah, a manual would be handy...have to get one...but just so broke at the moment.


It's times like this I wish I had my ol' gutless, inefficient and uncomfortable EH wagon...
...at least you didn't need a science degree and robotic arms to work on the thing. :^)

Thanks again Hako...good luck.

Power at one of the 4 pins probably was the fuel gauge power...not the pump which is only powered for 2 seconds(violet wire). Sequence of events when starting is ignition ON - power to fuel pump for 2 seconds - engine cranks - when engine starts power to fuel pump is restored.
If the pump doesn't run for the 2 seconds it will not start.
Don't pine for the old EH.....I had an EJ for many years and just recently had a drive of a restored example and found the steering very vague, brakes hard plus uneven, seating slippery, full of rattles and vibrations and sharp corners everywhere. We only remember what we enjoyed with the old cars.
With the complexity of cars like the Commodore, if you can get someone to show and explain all the gizmos under the bonnet it will become much simpler. A manual is a must and only buy a Gregorys in my opinion. Libraries have them for loan. I got mine from Ebay 2nd hand and you see them at garage sales/ lifeline etc. so about $20 should get you one. Then it all just becomes much simpler. Good Luck.

[ONEJZX90]

First thing i would do is bin the GOSS, i had 2 fail on my 500kms from Perth, fitted a Bosch pump that was only 10 bux more and never had an issues again. Mate that works at Holden said they have had quite a few GOSS pumps fail straight outta the box

[RUN415]

Drove in to 'Gambo' yesterday...mostly on LPG but had to start it 3 or 4 times on petrol with all the stops/stuff I had to do - started/primed up without any problems.
Relieved to get home again and that new Goss fuel pump is now looking like the guilty party...but it is not yet conclusive.

@hako
Yep...kinda knew about the fuel pump sequence of events as I've done lots of reading on these excellent forums and learnt heaps (been lurking for weeks)
...so the power test I did was on the prime cycle...set it up so I could (just!) see the test light turning on by leaning down as I turned on the ignish.
And yes, most certainly...no prime...no go!
Thanks again for ya help.

=============
@ ONEJZX90
Thanks for posting that info mate...interesting...and another coupla nails in the GOSS fuel pump coffin!
Just wonderin' if you tried to claim the warranty on the pumps? - I'm guessing you didn't as it takes weeks eh?

[ONEJZX90]

i got warranty both times, straight away as mate works at Veale Autoparts, so swapped em over and sent the old ones straight back to them. After having that issue i would tell anybody to spend the extra and buy the BOSCH one, even though they cost more

[RUN415]

= UPDATE =
Okay...have to go into town and do food shopping tomorrow...so I thought I better check the VS.
Stoopid fuel pump didn't prime...so I'm in a pickle again...being some 50k's from the nearest supermarket - and car part shop.
I'm all set to gamble another $100 and buy a BOSCH fuel pump...if I can get the car started.
(I tried once again to COLD start the car on LPG but it just turns over with no success.)
Bit concerned tho...'coz both the old and new fuel pumps seem to be exhibiting the same behaviour...which is...

1 - Replace fuel pump (old or new GOSS)...car starts fine. Add 10 litres of fuel.
2 - Drive into town (on LPG) do shopping. Start car on petrol then drive home on LPG.
3 - Car sits in garage for 6 or 7 days...then fails to prime when I go to start it.
4 - Botheration!

Today I swapped out a few relays ('fuel pump' + 'LPG check') and re-tested the 4 pin plug that plugs into the fuel tank/pump assembly.
Just to clarify, for other people diagnosing their fuel pump power...with the plug horizontal and clip to the TOP I got...
Pin 1 - Nothing
Pin 2 - Continuous voltage. (Ignish on - test light looked a bit dim so it may be low volts? HAKO suggests above this is prob for the fuel gauge)
Pin 3 - Nothing
Pin 4 - Voltage for 2 secs when ignish is turned/redlight

I tested the pump/prime 2 or 3 days after I last parked it in the garage, primed ok...so I thought it was going to be fine - no such luck.
Something weird going on...probably is the pump...wish I could be sure.
I might drain the fuel tomorrow...seems to help (even tho fuel doesn't conduct)...and it worked last time I did it with the new pump in.
Will let ya know how I go...will get it sorted eventually.

[RUN415]

Still failing...so I bridged the Fuel Pump relay today (pins 3 and 5 - the big ones)...and much to my surprise...discovered that the power plug going into the fuel tank assembly isn't connecting properly.
It's really really touchy...I think it's the first earth pin...cleaned them up and bent it a bit and got it working but I wonder how long that will last??? Not long I imagine...thank God for LPG.
Good news anyway...as I was about to buy yet another fuel pump...this chance discovery has saved me $100 and yet another FP changeover.
But what a headache this has been...and now it seems...mostly my own inept fault, for not doing this Bridge check in the first place.
Oh well...woulda been spewing if I had bort another new pump and had that one fail too...disaster!

So...wondering if anyone else has had the same problem...and what the fix is...short of buying another assembly from the wreckers.
(The blue rubber dust plug thing on the male plug seems okay.)