Fuel pump hide and seek

[aardvarkash10]

pumps arrived today. Made in Canada, sold out of the USA, delivered to me in NZ and they look great! Package includes new fuel strainer, terminals etc. Great value, or it will be once its in and I've made sure it works...

[aardvarkash10]

So I finally got the inspiration to fit the new fuel pump. A few weeks on, I sort of remembered how it all went together.

Clipped the old terminals off and crimped the new one's on, fitted new hose clips to replace the crimped ones I had to cut off, reassembled the whole shebang and refitted it all in the tank. With a little mineral oil lubricant on the sealing rubber ring, it all just slipped together surprisingly easily.

Went to start, battery was flat. Bloody hell. With a jump start from Snork, Moomin failed to do anything. Then his fuel relay started hammering out morse code. Bugger.

Pulled the relay, checked it all over, swore a bit, and reintroduced it to its home. Hit the switch, built fuel pressure to 40psi, cranked and started. Woohoo!!! I can only assume a dirty terminal or something as the only thing I did was slide the relay out and in again.

Moomin idled for 15 minutes while I buttoned everything up. The tank was almost empty, so I set off for a quick round-the-block. He died 400m down the road.

Towed back. No fuel pressure. Went and got 5 litres of petrol, tried again, he went. Went for another test drive, but he keeps dying on over-run like when you pull up to a stop. Started straight away each time.

Got home, he idled ok, I switched him off and he has refused to start again. No fuel pressure again. Pump is going, relay switching ok tacho jumping etc etc. But no fuel pressure.

I suspect the pump is sitting higher in the tank than previously and is not reaching the fuel because the level is so low. We'll see.

I'll keep this thread going to build the community knowledge base. And for hurbris - the damn thing is not going to beat me!

[Laird Scooby]

The cutting out on over-run when you only have 5L of fuel in the tank is pretty self-explanatory Ash - you've come off the throttle so the fuel has all gone to the front of the tank, starving the swirl pot round the pump at the back of the tank.

I'd suggest adding a minimum of 10L to the tank before worrying about other faults that may be present. More than 10L if it's practical for you to do so. That way you eliminate any possibility that the pump isn't sitting where it should in the tank.

I hope it is just down to fuel level in the tank and nothing more sinister!

[aardvarkash10]

Originally Posted by Laird Scooby

The cutting out on over-run when you only have 5L of fuel in the tank is pretty self-explanatory Ash - you've come off the throttle so the fuel has all gone to the front of the tank, starving the swirl pot round the pump at the back of the tank.

I hope so, but it feels more like a throttle switch or MAF sensor fault. Either way, not a biggy.

Originally Posted by Laird Scooby

I'd suggest adding a minimum of 10L to the tank before worrying about other faults that may be present. More than 10L if it's practical for you to do so. That way you eliminate any possibility that the pump isn't sitting where it should in the tank.

I hope it is just down to fuel level in the tank and nothing more sinister!

I got a bit physical putting it back in, so it won't be a big surprise if I dislocated the pump somehow. He used to run down to the warning light, and that is off atm, so its worth going back in for a look.

[mocambique-amazone]

Hi Aardvarkash, I've seen a few pumps sitting in a angle to the right after swaping the in tank pump. If the car will starve especually on fast hand right corners the pump is out of position. Laird Scooby did post a diy to swap the pump. It is important to compress the pump itself to the top of the system when try to fit it into the tank. It won't be in right position otherwise.
Did you open the white relay for the pump? They "click" and don't switch because of the soldering. You nee a very closer look with good eyes ( better be shortsighted) or/and a loupe.
The soldering around the shafts of the terminal to 30+ and to the pump get cracked first.
The LH2.4 equipped cars will die on the way to the traffic light if the speedo signal is missing.

Good luck, Kay

[Laird Scooby]

Hmmm, if it's dislocated then first it could be holding the sender unit above the level when the light comes on and second may (as you suggest) not be sitting fully down where it should.

I'm guessing the 940 pump/sender unit is similar to the 7xx pump/sender unit so the "Feed Me" light should come on at 2 gallons (9L) or less. Also if you get it in the right place, it literally drops in apart from the last little bit which is achieved by tightening the lock-ring.

Don't make the same mistake as i did and forget to check tighten the lock ring in a month or two - the pump/sender unit and seal "settle" together and the lock ring in effect becomes slightly loose. Not that you'd notice, i used a piece of wood as a drift and a 4lb lump hammer to "final tighten" the lock-ring.

[aardvarkash10]

Thanks guys - I'm picking it will be something simple. Yes I compressed the sender, and yes, I used a timber drift to "final" the lock ring.

The entire unit is lined up exactly as before - I took a photo cos I don't trust my memory these days!

I reckon I can pull it all out pretty quickly after all this practise, so I'll do that and ease my fears, and then I can embark on anything else if its ok.

[Laird Scooby]

No disrespect Ash but i found the first time i refitted it and it looked exactly the same as before, it actually wasn't!

It's very hard to see but at the top there is a small triangle etched into the sender plate (or are there two, one each side that should be horizontal - i honestly can't remember but you'll figure it out if you find one) and that triangle should point to the top. If they're the two triangles they should be side to side.

What i also found with mine is that with the arrow(s) located correctly, the sender/pump unit didn't seem to sit right until it was fully in and then it did literally fall into place.

Maybe that will be helpful - hope so!

[aardvarkash10]

REsolved. Took the entire tank unit out again and, as surmised, the pump had come adrift. The spring clip that holds it to the sender float was not up to the task.

The judicious application of cable ties firmly reattached the pump to the float to assist the spring clip. *Trick for anyone reading this* If you use this technique, secure the cable tie low on the pump ie around the plastic socket the pump motor sits in. If you secure it too high, the float cannot move freely to its upper position. This wont affect fuel delivery, but the fuel gauge will not read correctly from about half-full up.

The stalling at over-run has now ended. Dave - I think you nailed it. Not enough fuel pressure as fuel ran forward in the tank and the pump, already sitting upside down and back to front, couldn't deliver.

Cheers all - have a great Sunday to all you on the other side of the date line.

[Laird Scooby]

Cable ties - the universal "fix-it" tool!

Glad you got it all sorted Ash!