LSD

Hi guys,

Our S2 cab seems to of developed a real annoying problem, when under load and on boost say 2500 rpm up, it misfires, real lack of power and pops and bangs out the back. I have changed the distributer, cap, arm, leads,plugs, (ususal suspects) but was wondering if it could be a lazy fuel pump, it is a S1 pump and I have no idea how many millions of gallons its pushed! so would low fuel flow/pressure cause this problem? Also has had bad starting when hot since it was built,....any help would be great!!

thanks for looking

SafeChav

I was going to say the dizzy, but you say you've changed the actual dizzy itself (with the black plug)

LuiPoland

problems with fuel delivery can cause such problems - check AFR under boost

also check ignition coil

NEEDFORSPEED

im gona say the same as a few of us have had this prob and its been the pump

SafeChav

Is your pump noisey? And is it retaining fuel pressure

LSD

Alright there guys, thanks for the replys,

I have not as yet changed the coil, but have never known for a coil to break down on what feels like just the one cylinder, normally all for would sod about and would have trouble starting?

As for the fuel pressure and pump, I dont have a fuel pressure guage to hand at the mo and Yes safechav, the pump is a noisy old crap one, I will be doing some engine work in the new year and will start with what most leave till last...the fuel pump, but am not totally sure which to use, someone suggested the es cos pump, but I thought they where inboard pumps? any ideas?

would prehaps a worn inlet lobe on the cam be a possibility?

Are the injectors on the mfi's prone to failing? they have all done moon milage these days I know, but not heard of anybody having trouble with them. any more suggestions would be great.

Thanks

wez

oh, stupid question, whats AFR?

SafeChav

Indeed what you say about the coil is true, if its a conventional coil it won't affect one cylinder, that would be the cap/rotor arm etc.

Now.........a noisey pump is usually a fucked pump. You don't need a gauge to test the pressure in this respect, if you leave it say overnight, and then push the flap on the metering head, you will soon be able to tell whether the pressure is there. And you can prime the pump after for a comparison if you aren't sure

If theres loss of pressure the one way valve screwed into the pump is also gone. Pump wise it would be a sierra cossie one you're after, they are external.

Did i just hear you say CVH cams and wear in the same sentence ALL the lobes are prone to wear lol. But it would more than likely tap if it was the cam - vernier caliper will soon reveal all.

Injectors - they can start to leak when they get old being as they are pressure operated injectors, and is quite common again.

AFR = Air Fuel Ratio

LSD

Safe chav, thanks so much for that

Im going to source a sierra cos pump then by the sounds, are there any variations in the sierra pumps, flow rate ect between the 2wd and the 4x4? just if im going to upgrade I will go for the best I can get, Otherwise I could get in touch with Ahmed and get another one through him.

Thanks for the advice on the fuel pressure on the pump side of the metering head, but the last time I checked it was nice and firm and did not flap about! So at the moment I wouldnt of thought the one way valve on the pump was shot, but thanks alot for the idea

The most bloody annoying thing is the fact that I cant souce the actual cylinder failing under load, its like a needle in a haystack!!!!

As for the cam.......silly question I suppose, As like you say, they all wear badly, just the engine in the car is a bit of a unknown quantity as it was a donor from a S1 to get us by and that had alledgley been rebuilt ect, I must admit I expected it to of gone bang or play up long before now

SafeChav

Im not too sure if theres variations on the cossie pumps, but even a standard one is higher flow rate than a RS Turbo item. Speak to Ahmed im sure he will know

There isn't a great variation on how the flap feels with pressure and without, its how it springs back that is the give away. Give it a check anyway and then prime the pump up and compare....you would be surprised. The valve being gone would also explain your hot starting problem!

LSD

Thanks for that mate, Really appriciate the help. I will give that a check tommorow

take it easy

SafeChav

Let me know how you get on