Fuel pump problems!

[GTphil]

Yesterday I fitted a sytec 7bar rated fuel pump to my raider. My standard pump was making the car lean out at high revs with some decent boost.

Took the car out for 30 miles or so with new pump and all was well fueling right up to 7k in 4th and 5th at 20psi.

Today filled up at the petrol station,i was on my way out when the car stalled

Half hour or so later of head scratching after testing the relay I wasn't getting fuel to the carb, f i bridged the relay i could hear the pump running but still no fuel to carb.

So Mr AA man came and rescued me he tested the wiring with relay in situ and all was well and then i couldn't get the pump to run even if i briged the relay.

Just whipped the new pump off and wired it up direct to a 12v supply and it still wasn't working wired up the old standard pump in the same way and it fired into life.

Any ideas what can make a new fuel pump die very quickly like this??

I have heard that you are advised to use a pre-filter, all i did was just relace the standrad item with the stronger one and assumed all would be well.

[GTphil]

After doing a bit of reading up it seems that the use of a pre-filter is highly recomended.

Does anyone else use a pre-filter for there stronger/uprated fuel pumps?

[Scoff]

does the pump spark when you connect it to a battery, and get warm if you leave the wires connected ? If so then it's seized, maybe because it's sucked some crap up. Sometimes possible to un-crimp the end and get into the pump to clean it out. If it doesn't spark/get warm then it's probably fubar!

[GTphil]

No heat spark....nothing also it kind of makes a funny rattling noise when you shake it. My fuel did run very low before hand and as the fuel tank hasn't been cleaned out for 20 years i suspect a bit crap might have been in there.

Having read few a few things via searches on google the tolerances are so fine that even the smallest bit of **** could cause "instant pump failure"

And by the sound of the guy on e-bay not much chance of getting a refund/replacement if it wasn't fitted with a pre-filter.

I have bit the bullet and purchased another pump with a pre-filter this time

[Scoff]

I suffered the same thing once many years ago with a GT, new pump must have been a lot tighter than the sloppy old one, it lasted a few days. I tore it down though, actually found a shred of plastic carrier bag inside the pump gears, sucked in from the tank ! I cleaned it out and it ran fine again. By the sounds of it your's has gone open circuit for some reason so may not be so easilly fixable.

[GTphil]

I will have a look anyway, I'm pressuming that it running with whatever blockage/bit of **** has caused it to fubar!

No loss opening up now anyway!

[GTphil]

Ok Team!

I have a new fuel pump sitting hear waiting to be fitted also a pre filter for it too.

My question is as standard there is normally a filter after the pump. Would it be ok the bin said filter and put one before the pump only?

Logic tells me yes as the fuel will already be filtered going into the pump and thus clean when it comes out.

Reason is i won't be able to fit two filters and the pump in the space provided unless i really pikey it in and have the filter after the pump hanging down! lol not really ideal

[IANMM]

i suppose the filter helps after the pump just in case you get debris of the pump.....i would just take off the fuel tank and give it a good clean out then you wont have the prob with crap going through your pump pre filter..

[car.crash]

Won't having the filter before the pump restrict the flow and provide less fuel to the regulator because now the pump has to suck it out of the tank through a restrictive filter before it can power the fuel along the lines at a higher rate.

[GTphil]

Firstly, I frankly can't be arsed to pull the tank off and clean it out

Secondly the pump is suppost to be able to flow 7bar max or 135liters per hour at 3bar with a pre filter in place.

[car.crash]

Have a look inside the tank as there is a filter already in there. Make sure it's intact.

[RussellT]

I would recomend that you clean out the tank. Its a bit of an arse of a job and really quite dangerous so do disconect the batery first and make sure you dont use anything that could give off a spark near the open tank.

You should find that you allready have a prefilter at the bottom of the sender unit and this will need cleaning. Also I had bits of sand in there that were getting sucked onto the in tank filter and blocking it.

I found that having run the car untill the aux pump came on. it was easy to siphon the remaining fuel out and in doing that the debris was carried out along with the petrol.

One other point 7bar might be too much get the bosch pump from CGB.

[GTphil]

Just taken the sender unit out and the filter seems fine. nice and clean.

Got the car running again with the pre-pump filter in place and no filter after the pump it seems to be running fine fueling straight through the rev range as before if anything it seems a little bit richer.

Checked the pump after the drive(only manages 15miles as my brakes started to jam on!) and it seemed very cool/not overworked/starved.

The pre-filter is meant to double up as a pre carb filter also i.e like the standard fuel filter. it is a sytec jobbie with 12mm push on fittings.

My main concern was that it was going to ristrict the flow of fuel to the carb but it doesn't seem to have done and as I can monioter afr's i will be able to see as soon as their is a problem with fuel delivery.