Erm, would it be a noticable noise? or something you could hear if you were listening for it? Because i haven't by chance heard anything coming from the fuel pump, apart from obviously when it primes when you turn the ignition on. I take it , it isn't a massive job to change either pump?
normally its a quiet buzz, when its getting starved of fuel it gets loud. put it this way, with door open and engine running you shouldnt hear it!
Hmm, now that you mention it, there is like a faint blowing/buzzing noise coming from underneath the car somewhere, i thought it was a slightly blowing exhaust, but it could be the fuel pump? First thing to try is the lift pump then, yeah?
well it should buzz quietly, but if you can hear it easily over the sound of the engine then summat aint right! Its just in front of the drivers rear window, have a listen. It should humm quietly, if it makes bubbly noises or gets louder/quieter it could be the lifter pump is starting to fail and its not getting a good supply of fuel. That big plastic surround should be full of fuel at all times, as its being supplied by the in-tank pump + its getting fuel from the return from engine too!
Got the CO set by a garage today, apprently it should be 1.00, but the closest they could get it was 1.39? Anything that could cause that? Also, the MFA vacuum hose wouldn't effect the ECU in any way, would it?
1.39 is well within 'book' spec, how does it drive now? as long as there is no vacuum leak it wont effect the ecu.
Just about the same, TBH. A little smoother. Was going to inspect the lift pump earlier, Got the inspection panel off, where the was LOADS of grey dust underneath. Couldn't undo the twist on cap that holds the lifter in.
managed to get the cap off with a set of gland pliers! Ordered a lift pump from ebay this avvy. If that doesnt sort it, i spoke to darren from g-werks and he said he can have a look at it. Good thing about having a vw specialist in your town!
Fitted the lift pump, was pretty straight forward. Car _seems_ to be smoother, and slightly more eager to rev, but it still isn't RIGHT. Next try is HT leads. Although im not sure that just throwing new parts at it, is the most cost effective way to go about things.
It appears that i don't have an earth strap to the gearbox :S The haynes manual shows it goes on a threaded stud on the very right hand side of the engine bay, near the electrical connection on the top of the gearbox. I have an earth that goes to one of the gearbox-engine block bolts, near the hall sender for the dizzy. Is this right? Should there also be one on this threaded stud? If there should be one on the threaded stud, where does the other end go to? Thanks. Dan.
you have the later setup is all, better path to earth than the stud setup in the haynes. if you didnt have a gearbox earth, you also wouldnt have a working ecu right now
IF the ECU was shagged, i guess the car wouldn't start at all? This is really ****ing me off now! Stupid car. Wish i brought a saxo
Did your garage check the fuel pressure? That would tell you if the pump is working properly, and if the FPR is holding the correct pressure.
No i don't think so. He was saying stuff about vacuum hoses and hydrocarbons, and how he thinks the ECU is just "chucking" in fuel, and hoping it burns, but tbh, i didn't really think he knew what he was talking about. Like the ECU was in limp mode, or something. But i didn't think Mk2's had limp mode?
if that was his diagnosis id say your fpr is at fault, the ecu doesnt have a limp mode as you rightly say, and it relies on the fpr keeping the pressure in the fuel rail correct. Another reason for overfueling could be a blocked return line, summat up wi the injectors, or a vac problem to fpr edit: oh and possibly a ground short to the injector rail, meaning they're stuck wide open rather than being pulsed by the ecu.
Well, fuel came out of the return line that goes to the intank fuel line, so that isn't blocked. Thing is, it pulls really well up until about 4k, and it seems to misfire after about 5k. To me thats either a lean misfire, or an electrical problem? Think it's going to G-werks tomorrow evening, see if they can do anything with it. It's drinking fuel like it's no-ones business too.
if its drinking fuel and misfiring after 5k that suggests to me its overfuelling, when you have the throttle open fully it switches to rich-running. You mention fuel came out of the return line, where did you check it?
At the lift pump return? So, is it new FPR time? A new one from GSF is about 90 quid, I guess a Genuine, or pattern one, would be better than one of those adjustable "performance" FPR's?
