Fuel pump problems...help please

Hey after some advise please...

So the engine has done the odd cough recently, and the other day, one bank completely died.

After getting home running on one bank and being p***ed off, I read a few forums etc and did some diagnostics, its the what next bit I could do with some help with.

I checked:
- all the fuses and relays, they are all ok;
- I disconnected both exhaust ECUs and the car still ran on one bank only;
- I then swapped the ECUs and the car still runs on the same bank, so they are fine;
- I then disconnected the fuel line at the fuel filter for the bank not working, whilst the engine was running, and nothing came out at all.

Clearly a fuel problem. My initial thought was fuel pump; but reading some threads it appears that the crank sensors tell the fuel pumps when to kick in?

I will check that the pumps get voltage when the ignition key is turned on (tomorrow evenings job).

I would have through that as soon as the ignition key is turned on, the pumps should prime irrespective of the crank sensors. Hence if I listen/feel at the fuel pump and get somebody to turn the ignition key I should be able to detect if the pump is priming. Is this reasonable logic?

Also if I do need to replace a fuel pump, are the pumps actually in the tank and I have to drain the tank, which seems to be the case and just plain stupid!

Appreciated
Adrian

 

Which model?

 

dooh! 348TS 1992

 

I got to look it up before I can tell you if the pump is running when the key is on without ignition. I don't think so because of safety reasons.

you can test the fuel pump by itself by crawling underneath, disconnecting the wires, and apply 12V to the pump. It should whir.

If it is bad and needs replacement, you have to drain the tank. Stupid? This is an Italian car, stupid is a feature.

 

Putting fuel pumps in tanks is considered a safety feature (especially on aircraft), in theory at least. It keeps the pumps cool being immersed in fuel, and if the pumps leak, the fuel just goes back into the tank. On aircraft, however, the pumps can usually be removed without draining too much fuel.

 

Crank sensors need to see 30 rpm to turn fuel pumps on

Simply hot wore the pimps to see if they work

 

I read that as "simply hot-whore the pimps to see if they work," which would have qualified it as the greatest sentence written of all time.

 

How do you hot wire the pimp? Does it take a couple of employees?

 

I know what Santa is bringing you kiddies for Christmas LOL

 

You put two wires in the stove burners for a while and then invite the pimp over!,

 

The fuel pumps do not run with the ignition "on", they will start running when the engine is cranked based on the signal from the crank sensors. The first thing to check is the fuel pump relay (see attached pic). Pull it out and clean its pins, check if it works and check the socket for any melting signs. If the pump still does not work, check fuses 8 or 19 depending on what side pump does not work (the fuse might not be blown but its pins might be corroded/burnt). You can test the pump by inserting two male spade connectors in the pump relay socket where the relay pins 30 and 87 go (see 2nd pic) and jumping the connectors with a piece of wire. You do not need to switch the ignition on for this test.

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Starting a major service on my 348 spider. Daniel from Racambi let me know with the ethanol fuel today, it attacks the rubber boots around the fuel pump. This sluffing off of chunks of rubber will stop the fuel pump from pumping fuel and the rubber chunks drop to the bottom of the tank and clog the pick ups. Not sure if your earlier car mine is a 94, has these offending boots. While the service is being conducted I am removing the pumps and rebooting. I am also sending the tank out to be steam cleaned. I'm a belt and suspenders kinda guy and doing everything possible now to make my touring season trouble free. I'm replacing every part that moves, rubs, applies pressure, all bearings, seals and wear items in the timing case, including Daniels new improved water pump. It is more expensive to do "everything" that moves replacement but in the long run peace of mind is worth it.

I would check the flow of fuel from the pump, check the ohm draw on the pump leads and the old stand by put your ear to it and listen for noise. As a rule things jut don't stop working with out prior notification of some sort. Basic diagnosis is your inexpensive friend in this case. I believe new pumps are north of a couple of grand. The new boots are $130 each.

just sayin'

brasscarguy

 

Not really, $170 with free shipping https://www.ebay.com/itm/LANCIA-FERRARI-348-412-512-GTS-Mondial-Thema-Bosch-Fuel-Pump-2-8-5-0-1984-1999/162511268155?hash=item25d66d293b:m:mpatrkrtoVbEwmexB3r4L4w&vxp=mtr. I have bought a number of things from this seller (including the pumps) and his shipping is reliable (with international tracking).

 

Ok, thanks for the replies so far!

I hot wire the fuel pump this morning as per above and it ran no problems.

I also ran the car and hot wired the pump, but it still only ran on one bank. I'm guessing/hoping that the crank sensor not only tells the ECU when to fire up the pump, but also when to start the ignition as well?

I'll order a new sensor and see what happens.

Does anybody know what sensor runs what bank? I could disconnect each intron and see what happens, but....

Appreciate your help so far.

PS Not sure how we got onto pimps, but somebody is not giving FChat there full attention

 

“If it is bad and needs replacement, you have to drain the tank. Stupid? This is an Italian car, stupid is a feature”
Funniest quote I’ve every heard on this forum.......

 

Like he said they are universal bosch 44 pumps I believe is the number

 

You'd best just plan on replacing both crank sensors. $25/ea Kia sensors. Plugs andespecially wire insulation deteriorate over time.

 

I don't think the fuel pumps for the later 348's use the cheap Bosch pumps. The ones in my spider is quite different from the Bosch 44's.

just sayin'

brasscargy

 

Yes use the kia sensors. They last forever and much better than Ferrari at a fraction the price.
Kia sensors are like the 1st 348 hack ever done.
https://www.ferrarichat.com/forum/posts/138368426/

 

Ok, refitted new crank sensor.

Started the car and it still ran on only one bank. Turned it off and looked at the crank sensors and checked the connections again, and then it ran fine...for about 5 minutes then went back to one bank.

Any suggestions? Do I need to reset the ECUs or anything?

Cheers
Adrian

 

Any CEL or SD lights on when the bank doesn't run?

 

nope, no warnings lights. l turned everything off and left it for a couple of hours ands till runs on one bank.

Guess I'll swap crank sensors over. That should tell me if the new sensor is faulty or if there is a fault somewhere else!

 

Well, I'm not familiar with the 92 348 and how the warning lights work compared to a 355, but once thing you might want to do is check continuity of the harness between the ECU and the C-sensor. Check each of the wires separately. I had a similar problem with my 355 this summer. Sometimes it would run fine. Sometimes it would break up badly. Then it just quit on one bank. Replaced the C-sensor and it ran fine for a while. Then lost the same bank again. Turned out to be an internally broken wire that would intermittently make contact. The wire broke inside the insulation right at the point where it was crimped to the pin in the connector at the sensor end. I had to pull the pins out of the connector housing and pull slightly on each wire. Sure enough, for one wire the insulation just stretched. Wire broken inside.

 

As John said above. Time to check the loom.

 

actually the go slow light flashed for a second then went out as I was running it again. Though it might need some time to prime the fuel system, ran it for 5 minutes but still nothing.

I'm also thinking dodgy wire. Anybody know what pins the crank sensor goes to on the ECU connector?