plynchy

Just had the Saff out for the first time in 2 years for it's MOT, which it passed amazingly.

Is running fine on light throttle, but under full boost it's hesitating (as if it's not getting enough fuel), my first thoughts are the fuel pump as it sounds a bit "rattly" and it's the original item.

Anywhere else I should be looking or testing before I blow it up??

Ta.

kosienutter

check the spark plugs or better put standard 071c motorcraft plugs in. i had similar issues and was later told the ideally need changing every 10,000 miles. when was yours last changed

plynchy

It's running a new set of PP8's. Been using these for 7 years or so with no problems.

It's stage 1 by the way, running 14-15 psi.

jon@work

iTrader: (5)

when was the fuel filter last changed ?

john_p_b

iTrader: (4)

is it running on 2 year old fuel? unleaded goes to shit if it's left for any length of time so if you're not already on a fresh tank of fuel then get it filled up. also check the plug gaps.

plynchy

Thanks chaps.

Fuel filter was changed maybe 3 years ago but done around 2k miles since. The fuel is pretty recent TBH.
As for plug gaps, pretty sure they're twin electrode jobs IIRC and not adjustable as far as I know but i'll have to check. They're Ford PP8 platinum plugs, std fit on Escos' I believe.

If anything i've typed is made up please put me right!

john_p_b

iTrader: (4)

you can adjust the plug gaps on the pp8's. They're meant to be at .8 standard but i've checked plenty straight out the box and never found one yet!

tabetha

PP8 are std single electrode, could try a smaller gap, are you on std ignition coil ?, mine wouldn't even start the car when set to the correct gap the coil was so weak!!
If the fuel filter is that old it needs changing even if it did no miles as being immersed in fuel bacteria will be all over it, if not rewired(pump) I'd also check voltage at pump under load.
tabetha

plynchy

You're right, plugs are single electrode, no idea where I got the twin electrode idea. Have gapped them all at .75, but they were damn close to that anyway.
Will get the fuel filter changed, but i've a hunch it's the pump TBH.
It's a std coil BTW, but again, it's always been spot on.

tabetha

I would personally on a std coil put the gap at 0.6mm, check the voltage at the pump under load, but also check the fuel pressure is correct, for around Ł35-Ł40 you'll notice quite an improvement in response lower down and smoothness with a "group a coil".
Pumps have had sometimes 6-8volts at pump under load due to old wiring, 2 must do's on a cossie are fan rewire and pump rewire, asking for trouble and expense if these two not done as a minimum.
tabetha

plynchy

OK, have changed the fuel filter and fitted a sparkly new Grp A coil. Just had the car out for a 10 mile run, was spot on all but 3 times on sustained full boost, almost felt like it was out of fuel when it did hesitate.

I'll try and get the pump voltage tested tomorrow, but the pump itself still doesn't sound brilliant.

pete mcrash

iTrader: (1)

try motocraft 071's.........Ł2 each.................only had pp8's once in a cossie i bought.....they were SHITE.......never used them since......but it also could be hitting boost cut.......or leads,dissy cap etc......maybe take it to someone else in the crsoc....for a second opinion....

plynchy

Cheers Pete, been running PP8's for years in the car with no problems, this is a brand new set. Don't think there is anyone within the CRSOC that could give me an educated opinion TBH (no offence intended) as they don't really have any techie heads AFAIK when it comes to Cossies.

Regapped the plugs down to .6 today, the problem has intensified and now got fuel pissing out of the regulator all over the dizzy etc. Nice.
If the regulator wasn't controlling (i.e. was shut) would the pump build enough pressure to cause the pipes to leak?? If the regulator is fooked than that would explain the problems if it is opening and closing when it feels like it, rather than maintaining a steady flow.

Checked the pump voltage also on full load, got as low as 11.8V, nothing to be concerned about IMO.

Any advice gratefully received!

james kiely

iTrader: (5)

would like to check my own pump under full load as it is hesitant on full boost aswell,how did you check yours mate?


cheers james

plynchy

I bared back the pump wires inside the boot (the loom runs up the back panel) attached some crocodile clips to them and ran 2 wires through to a multimeter on the dash. Ideally you want to check the voltage as close to the pump as possible.

pete mcrash

iTrader: (1)

just come on to say one of the vacuum pipes on the plenumn side came off mine once and it kept cutting boost on full load......but looks like ur problems are getting worse......

plynchy

So it appears...

Looks like the fuel around the regulator is coming through the walls of the return hose (it's that rubber overbraided with fabric type stuff) so the tubing has either gone porous or the return leg is partially blocked possibly.

Away to work for a week tomorrow so will get no further with it until next weekend at the earliest.

Whats the cost for a new regulator?

Stu @ M Developments

iTrader: (12)

Hello Paul,
In this situation I would drop the gaps to 0.65mm and see if it improves:

If It does:
You have an ignition gremlin. Suspect the HT leads / cap / rotor or voltage deficit to coil.

If It Doesn't:
Chances are you have a signal error. Suspect phase or crank sensors.

The PP8's you have are outstanding for stage 1 and cannot be bettered. Period.
Ensure you bought the LT model PP8s as the gap on the ST model PP8s is 1.2mm.

Your fuel leak is common, that piece of pipe regularly fails mate, just replace it before condemning the regulator. Chances are it always leaks under load as the fuel pressure on your car is around 1.5 bar higher on boost than it is at idle.

Regards pump voltage. Only check this ON BOOST at above 4000rpm.
The readings obtained at idle are largely irrelevant.

Cossy Mike

iTrader: (4)

Mine runs on PP'8 fine and never had any issues until i changed them to 071C's and it would'nt idle properly and would 'hold back' on boost. Once it hit 4500rpm it used to missfire badly.

I put the PP8's in and all my problems want away

Each to there own i suppose

plynchy

Thanks for taking the time to have a read Stu, much appreciated, will have a good play with it this weekend (pending the exhaust being repaired).

Ordered a new pump and a set of 071C's from you yesterday (for Ł11 it's worth a shot), promptly arrived this morning, spot on. I've factored in changing the pump anyway as it's 20 years old so it must be getting tired by now!

The pump voltage readings barely altered from idle to 5k+ RPM (thats driving it, not stationary).

Stu @ M Developments

iTrader: (12)

Thanks for your business.
Please note that the pump voltage readings wont change at all unless the engine is developing boost with WOT and actually under load.

This is because as the boost increases so does the fuel pressure which increases the pumps current draw substantially. Also, under these conditions the injector circuit is working harder which is on the same fuse box spur. This drops the voltage even further.

plynchy

What are you referring to when you say WOT?

I wired a meter into the pump circuit with the meter sat on the dash (test lead resistance less than 0.1 ohms), the voltage readings at idle were circa 12.3V dropping to 11.8V on full boost.

forevaford

iTrader: (2)

wide open throttle WOT

plynchy

Ta.

plynchy

Car now has:
New fuel pump & filter.
PP8's at .65 mm.
New fuel lines all over the place.
20l of fresh fuel.

Tried different crank sensor, dizzy cap, leads and still it's coughing on full load at around 5k rpm.
Had a multimeter on the coil and it's running around 3v on idle up to 14v on full load. Is that correct??

Only got a phase sensor to try then i'm stumped...

pete mcrash

iTrader: (1)

have u tried winding the boost OFF half a turn.......(or more)

plynchy

No Pete, haven't touched it either way TBH. It's gone to Motoscope now anyway as i've got an appointment witha a stag do this afty.

Neil S

iTrader: (1)

I've got a standard coil and a Group A one you can try if you want?

plynchy

Fitted a new group A coil Neil, but ta for the offer.

Will see what Motoscope come up with...

pete mcrash

iTrader: (1)

[quote=plynchy;4292421]Fitted a new group A coil Neil, but ta for the offer.

Will see what Motoscope come up with...[/quote]........a big bill and a shite car......................lol........

plynchy

Had Motoscope on the phone today, been out in the car and it didn't fault once, ran it on the rollers later with a fuel pressure gauge connected, after a few runs the fuel pressure dropped from 70 psi to 40 psi when on full boost (5k rpm), AFR went well lean also, which either points to the pump (which is new) or possibly the regulator.

Pump still sounds like it's cavitating tho, so may have a blockage in the tank somewhere.

Neil S

iTrader: (1)

Could be the wiring to the pump or the filter mate.

plynchy

It's a new filter mate, along with the pump.

Have already checked the pump voltage and it appears to be OK. Proper head scratcher this, don't like wasting money on parts that aren't needed, like I seem to have so far.
Grrrr.

plynchy

Just in case anyone was following this and has a similar problem...

Put Ł20 of fuel in and it'll be fine.

Ł350 later thats appears to be all the problem has been, a fooked fuel gauge, it felt like it was running out of fuel because, erm, it was. Even after I dumped a fresh 10 litres in it. Running sweet as a sweet thing now.

Doh.

pete mcrash

iTrader: (1)

fuckn daft townies................lol..........(fingers x'd that was the problem)

pete mcrash

iTrader: (1)

just to make u feel better........i've had an electrical problem for 18/24 month.......the cars been a cunt....only does it when there's nobody to fix it.....lol......anyway i finaly bit the bullet and got a new loom after trying everything else.........and guess what......it wasn't the loom...........still does it.........sick as a chip...............

Cossy Mike

iTrader: (4)

Bad news Pete, feel for ya now bud

plynchy

Why do we bother?? I'm seriously starting to wonder...