PI Fuel Pumps - RBRR Whinning Nightmares

[Pete PiEst]

The jerry cans finally turned up so I decanted some of the fuel in to them.

Unfortunately the Pierburg appears not to be working - it clicks but no whirr - Any ideas if it can be recovered ?

So I was left with the other 2 pumps the original Bosch 044 and a replacement that I'd bout which was Sytec OTP979 - both of those had an AN-8 input drawing through a 50 micron bullet filter..

Here's a video of the OTP979 transferring some fuel.

[iani]

I'm running the OTP979 in my PI Saloon Pete, it seems up to the job but I've not done many miles on it. I fitted one on the advice of a friend who is running one in his Mk1 PI saloon successfully.

Ian

[Pete PiEst]

Could this be nominated for an Oscar ??

I spent a couple of months "getting in character" I hope my many hours of selfless devotation to my craft shines through in what I humbly call "My Masterpiece !!"

I give you "Bosch-044 !! "

[Pete PiEst]

The Pierburg lives ! .. I connectedit directly to a battery and it's spinning.. I'll see how it does transferring the remainder of the tank tomorrow ..

[Nick Jones]

OTP979 seems really quiet - not sure if I’m getting any sound on that clip. 044 sounds ok.

Good news that the Pierburg is alive. Giving them a few gentle taps on a wooden surface with power applied usually gets them going if there’s any life left in them.

[david langrick]

On 10/10/2023 at 20:58, Pete PiEst said:

Hi All,

I've got a DIY BOSCH 044 conversion on the estate, which has done well for over 10+ years but on this years RBRR it decided to give us a "challenge" towards the end. From just before Bude to just after Honiton it was cutting out with a lack of pressure and we wasn't too sure if we were going to make it back to Knebworth 🤦‍♂️🤦‍♂️

It was getting hot and making quite a racket !!

We got round this by removing the spare wheel in the estate and leaving it open along with the windows. This allowed it to keep cooler.

I've just checked the fuel filters both pre and post pump, both fine.

The problem with the estate is that it has to suck the fuel out through the top of the tank through a pipe with an ID of 6mm.

My new plan is to get a new outlet welded on to the tank in AN-8 the ID bore of the aluminium hard line is around  10mm the flexible tubing is around 11mm and 9.5 for the fittings.

The pressure side of the pump and post filter is already in AN-6 up to the distribution block of the PRV.

So my question to the Pump-ologists is:

1, Do you think AN-8 is large enough?

2, Is AN-6 OK for the pressure side or should that be increased to AN-8?

3, It has a diaphragm PRV and  the over pressure return is in ID 7mm. Should that be increased ?

Its not an electrical supply problem as the pump is fed with a direct line from the battery through a 30amp fused relay. The relay also has a direct earth back to the battety. All cables are rated at 30 amp. They were cool to the touch when the pump wasn't !

Views etc appreciated👍

Looking forward to the 2025 run !!

Cheers,

Pete

Hello Pete

i read that you have a filter on the high pressure side. On the original Lucas- Triumph set up there was never a filter after the pump...

[Pete PiEst]

Hi Dave,

True and there is a fine filter on the inlet to the MU.

I've got a T piece just before the MU and that's where I take the pressure reading so I'm assuming that the post pump filter isn't affecting it too much.

What were you using on Maiden before you went back to the 18th C??😂

Cheers

[Pete PiEst]

I've had the bung welded on the underside of the tank and have sorted out the plumbing from the pump to the prv.

Am waiting on a couple of bits for the fuel tank stopcock.

Needed to raise the spare wheel off of the floor so there's room for the stopcock and pre filter.

 

[JohnD]

Good luck,  Pete, you're doing a nice job!

I've had fuel heating probs, and while I think they are sorted one solution is a fuel cooler!   I was inspired by finding one on my TRansit van.

Lots of them about to choose from, from a length of pipe with fins, to 'proper' radiators, to what may be - I'm not sure - water cooled versions.    All diesels have them, for the same reason  we do on Pi, a high ratio of high pressure fuel returned to the tank after pumping, when the pump adds heat.  Petrol fuel injection happens at much lower pressure.

John

[frenchiemk2]

Vey interesting.

As i struggled a lot with my "long time ago convereted to Bosch french PI", i'm very interested in this post.

i had a very bad experience with the Sytec (OTP44 -3044.1), I bought 1 and since the begining had the "-' pole moving but did not fail at ignition, then when in order to run, there was a fuel leak at succion😬! then after few hours, it couldn't keep pressure charge and fainted.

If i had an estate tank, i'd certainly try to install a pierburg immersed fuel pump (new hole and cap) with bag filter:  no leak, no distance succion or hose diameter  problems.

On more recent car, those pumps can feed distributors for longer cars, and the filters can be located just before metering units like Audi 100-200 Avant turbo. I know, the Bosch K-jet needs less pressure than the Lucas M.U. 

Now i have put a real 044 Bosch but I still wonder if it's working good enough ( i guess YES because I poped out the injectors and they sprayed nice).

Also, i think i will try a swirling pot (because on long left turns with low fuel, the Pi tank is not helping and if you know a bit France, we have not only turnig roads, but also those roundabouts on every f.road...). 

I saw nice mountings here with Dash connectors, but did not invest in those, maybe i should.

One question someone may answer is about positive pressure : 

- in the tank ?

- between the tank and the swirl pot/external fuel pump? i think putting a small facett just after the tank to pre-feed the pot.

[frenchiemk2]

On 09/03/2024 at 16:19, frenchiemk2 said:

Vey interesting.

As i struggled a lot with my "long time ago convereted to Bosch french PI", i'm very interested in this post.

i had a very bad experience with the Sytec (OTP44 -3044.1), I bought 1 and since the begining had the "-' pole moving but did not fail at ignition, then when in order to run, there was a fuel leak at succion😬! then after few hours, it couldn't keep pressure charge and fainted.

If i had an estate tank, i'd certainly try to install a pierburg immersed fuel pump (new hole and cap) with bag filter:  no leak, no distance succion or hose diameter  problems.

On more recent car, those pumps can feed distributors for longer cars, and the filters can be located just before metering units like Audi 100-200 Avant turbo. I know, the Bosch K-jet needs less pressure than the Lucas M.U. 

Now i have put a real 044 Bosch but I still wonder if it's working good enough ( i guess YES because I poped out the injectors and they sprayed nice).

Also, i think i will try a swirling pot (because on long left turns with low fuel, the Pi tank is not helping and if you know a bit France, we have not only turnig roads, but also those roundabouts on every f.road...). 

I saw nice mountings here with Dash connectors, but did not invest in those, maybe i should.

One question someone may answer is about positive pressure : 

- in the tank ?

- between the tank and the swirl pot/external fuel pump? i think putting a small facett just after the tank to pre-feed the pot.

What i did : low pressure pump to feed the swilrpot, 044 pump to the line (Bosch set valve) and a pressure gauge on a T link  before the M.U

The prefilter will be changed for a bigger one.

Edited April 1 by frenchiemk2