Lambchop

iTrader: (1)

hello all
havin a strange problem with the cossie. take car out from cold and its all fine. as it warms up it drives fine and i can boost as i like. after 6-7 miles dual carriageway and then while slow driving through housing area the problem will begin.

when accelerating very slowly if you give just a wee bit too much throttle it feels like all power has been cut from car. hold the throttle constant and revs will slowly fall, car will splutter and then sometimes picks up and drives on. sometimes it feels like theres gonna be nothing altogether. back off the throttle just a fraction and bang she's back to life. slowly the problem gets worse to the point you have to be careful how much throttle you give at low revs or car will die. not all time but can happen.

when you slow down when its stuttering you can hear the fuel pump far louder than before. i almost think its as if the pump overheats and then cuts fuel temporarily. is this a common fault?

could it be down to anything else? sensors maybe?

my car has twin fuel pumps and second line is run for extra injectors. now i dont know how the hell to swap them over. Car had a slight leak when i got it and it was from the pump connection. AVA swapped it over to run the other pump but i wanna swap it back to see if it solves the prob. It looks like both pumps are wired up but the main line isnt connected up on the 1 thats off. how do you switch it so 1 pump does nothing? at moment the dodgy 1 is on and whiney and almost sounds rattley inside. the 2nd pump seems to vibrate but make no noise.
in engine bay you can see the spare fuel line and its plugged up. but surely theres no pressure inside? just that we cant see how to turn on only 1 pump. the connector goes to the bulkhead side of the fuel rail. is that fuel IN then? and then the return is after the regulator?

excuse my lack of clue but my mate robin will come see the post because he's having a look at it for me.

Any help appreciated!

chop

Neil S

iTrader: (1)

The return line is after the regulator as you say Chop

Can't help with the other bit I'm afraid, but I don't think the second pump should be wired up if it has no fuel coming through it - sounds like bad news for the pump as it's running dry...

Neil.

RichardPON

Chop - pic when you get a chance mate.........

Lambchop

iTrader: (1)

neil
its just we cant see how pumps are connected cos looks like they both are

anyone else?

rocky_robin

Thats a great attempt to explain the problem!

Right, both pumps are wired (plugged) in and the both go to the relays attached to the rear panel inside the boot. Something that I never checked was to see if they are clicking when the misses happen. That could explain a lot - too late at night to be horsing it about in a quiet street!
The cabling then runs through the car body to the front. I never took off any panelling to check for further connections.

Further to the many posts about cleaning the sensors, I pulled off the TPS sensor connection and noticed that 2 out of the 3 spades were not clicked in properly into the connector. That was fixed and put back on.
I never had a stumpy screwdriver with me to take the TPS off to clean it, but can do that later. Chop, have you driven it yet, since I fixed that connection?

Listening to the pump that is on, it's very clattery - like a clattery bottom end of an engine. It's like the bearings of the pump are a bit loose.

Just to enable me to systematically tick off parts that are ok, I couldn't see how one of the twin pumps was working, but both connected.
Again, without stripping off taped up relays, etc.

Lambchop

iTrader: (1)

righto just been for a wee drive again. 1st 10/15mins there were no problems then as described above it went all weird on me.

BUT i might have spotted something. i have 5 gauges in my car and i thought the bottom one was oil pressure but ive got a feeling it may be fuel pressure! i think this because when the car splutters the gauge goes to zero! what is a typical fuel pressure? When its not spluttering its reading 35-40psi. if i recall it maybe used to read higher than that...

chop

rs cos

I'm having a similar problem with mine at the mo? Is it phase sensor or crank position sensor? Is your rev counter ok?

Lambchop

iTrader: (1)

rev counter is fine yeah.

cps was changed when car was on rollers couple months ago because car had a funny misfire then.

im hopin its the fuel pump issue...

Lambchop

iTrader: (1)

this guy has EXACT same problem but frustratingly doesnt post up saying he's fixed it...

http://forums.turbosport.co.uk/bbs/s....php?p=1067768

costina

iTrader: (1)

Fuel pressure should be 3 bar 45 psi, at idle

could it b your fuel filter is blocked?

This would possibly indicate irratic fuel pressure!

just a suggestion hope you sort it

Lambchop

iTrader: (1)

cheers for reply mate.

surely a blocked filter would be blocked at anytime and not just whilst warm?

scruffythefirst

Sounds like wiring to me, probably an earth to something like the fuel pump relay thats getting a bad connection once its warmed up.

DaveEscos

dont fuck about

completley rewire the fuel pump circuits and replace the pumps/filters!

Lambchop

iTrader: (1)

dave
i think its coming to that!



if i was to do this what exactly is there to replace? Is there wiring running through the car front to rear? and then just through the boot floor to the pump? is there wiring/plugs/connectors to buy from ford? or is it something a garage could change out should i put it in somewhere to get done?


chop

DaveEscos

im sure AVA could rewire your fuel pump system with thicker guage wire

Pick up from the relay

change the two pumps for one Grp a job and het a new filter

job done



BLAP BLAP !!

Mike Rainbird

iTrader: (3)

If the pump is noisy, that has got to be your culprit surely, as they aren't supposed to rattle .

jon@work

iTrader: (5)

Have you noticed if it make any difference how much fuel is in the tank - ie if you fill the tank does it still splutter ? Does it only splutter with the tank about a third full or less ?

Lambchop

iTrader: (1)

dave
ava are MILES away from me so would have to get done close to home cos car goes tits after 10mins now

car has 2 gpA pumps as is. i should be able to swap over from dodgy one to the other but i need a new aeroquip connector which is broken. PON says its Ł20 and its a pissy wee bit how the fook much was all that aeroquip you bought?
get the wiring/filter done and hopefully the other pump is ok.

hmmmmmm


chop

rocky_robin

Swapping over the pumps will be simple..................prob is that I can't see how AVA has managed it! Did you call them to see what they did, even though both are still connected? If it's as easy as the wiring on the relays and connecting up the fuel rail, then cool. I just didn;t want to start stripping off black isolation tape, if there was no need to.

Mike, as soon as I heard that rattle, I knew the pump was not right, even though it did the job, hence why I want to swap them over, just to eliminate the pumps. Tis noiser than my 16i bottom end!

RichardPON

Hang on - I don't understand what the issue is......

You swap from one pump that you know that works fine to the other pump that's been sat unused for god knows how long and is probably knackered, and now you're wondering why the car misfires etc?

What was wrong with the original pump that was running fine?

Isn't this unbelievably simple? One pump is fine but the aeroquip connector's broken on the fuel line.

The other pump is knackered.

Seems fairly simple to me.

P.S. That aeroquip I bought was a fookin fortune!

Lambchop

iTrader: (1)

it aint as easy as you make out smart ass
i dont even know for sure if the pumps were swapped over or whether it was just the broken connector.

i do think they were swapped tho and the car has done loads of miles fine before developing the misfire so its not like we just started using an old pump and are surprised why it doesnt work

now it may sound so simple as putting the non broken connector across to the other pump and running it but as Robin says we(he ) dont know how its works. Rob is rather handy with his hands on cars as you may see from his car in the resto section so if he cant see it straight off then it aint simple as far as i see

fingers crossed we find it out tho

and yes i dont fancy seein your aeroquip bill either


jon@work
no mate it had between 3/4 and a full tank of shell finest.