Fuel pump on way out? Scirocoo mk2

[vitch]

Breaking News!!

Well not exaclty headline story but...

I started to read a little bit on how the fueling system works on these...is it bosch k-jetronic or something like that and it said that the components mentioned above keep it free from air an pressurised, now I know that when you take of the fuel cap to put some fuel in, you get a nice hissss as it's pressurised or something... well I don't get that anymore, thought i'd check it out this lunch so took it for a short run then took off the fuel cap... no hiss.

Does this matter, does this help me in someway determine what it could be...

if the tank fuel pump had gone would it stop the tank pressurising? if the warm up regulator had gone would this also stop it pressurising? if the filler neck had a hole in it with rot would it stop it pressurising?

thanks....

bet you guys namely "stecemac" are sick of responding to me... I know, i'm a lost cause

[vitch]

and theres more.......which could possibly be related

The reason i carried out the service was because of strange idling problems....when idling it was dropping very low and not correcting itself, it would never die but idling pretty low, but dabbing the accelerator pedal brought it up and it revved smooth (as it does now), it also drove fine with no problems. So i thought it was due for service, did the service but it continued.. then came the problem we are talking about.

Could it be that the pump was dying and not giving enough pessure and now has gone?

[stevemac]

If it were my car, I'd be fitting a new internal fuel tank pump & new fuel relay. I can't promise that this will fix your problem but it's as good as any other place to start.

Fuel system should create a vacuum in the fuel tank & not pressurise it. This is more apparent if you've just been driving fast or agressively.

GS&F Mercedes Benz Product Manager   (Corrado G60)

[vitch]

right, got the seat up... got the plate of... how the hell do i get the pump out, it doesn't seem to want to lift out, i can't seem to unscrew the whole thing and theres nothing apparent holding it down? I took of the clips attached to the hoses etc. but can't get it out?>

do i need a special tool to undo it?

[stevemac]

Can't remember exactly how it comes out but you definitely don't need any special tools. I changed mine (a few years ago) in a town centre car park - where it had broken down.


GS&F Mercedes Benz Product Manager   (Corrado G60)

[vitch]

your right, it just needed a bit of teasing... my friends had a little rust on the plate making it difficult to pop off...of course i didn't want to damage it so was wondering if it screwed out or just popped off... in the end with a bit of force and a screwdriver it came free.

Mine came off rather nicely actually and then i swapped them over... thing is, it didn't work, i replaced the relay at the same time and it was juddering just the same... In fact it made the other fuel pump whine like a poorly dog... so i guess this hasn't helped.. I put my old pump back in just because i didn't like the whining the other pump was doing...

So all in all just a changed relay.

I was half way doing the warm up regulator but it got dark... going to tackle this one tonight. fingers crossed it's that.

would this also help the delayed start that I've always had.. My car has always taken a few seconds to fire up and only does it when i give it some gas at the same time.

If the warm up regulator doesn't work, is there anything else I can easily check for before sending this to the garage?

I have a Haynes manual now to help me along

[stevemac]

It's quite possible that your delayed start will be caused by "weeping" injectors. The injector spray jets wear with age & can cause slow starting.


GS&F Mercedes Benz Product Manager   (Corrado G60)

[vitch]

Hello.

Well replaced the warm up reg. yesterday...don't think I've fitted it correctly as now it is really underfuelling....its a bit tricky lining thos nuts with the holes in them to the fuel lines.... gonna try again this evening.... any tips on getting the pipes in line with the bolts with holes in?

[stevemac]

The holes in the "banjo" bolts do not need to be aligned with the pipes. The inside of the unions on the end of the pipes are slightly concave & constructed for the fuel to flow freely all the way round the top of the bolt. If you closely inspect inside of the unions, this will be apparent.

You're certain that the car is underfuelling ??

GS&F Mercedes Benz Product Manager   (Corrado G60)

[vitch]

banjo bolts.... I like the name.

well that makes sense then as I thought this is very difficult to align. It must be a faulty unit then... which wouldn't suprise me as his banjo bolt did seem to have accumilated a bit of crud I cleaned them out before instal and the port that the banjo bolts plug into. this must be why its even worse. this is why i think it's under fueling.

I will put my old unit on tonight and purchace a new unit from you guys 80 squids i think at the weekend.

someone mentioned breather pipes? what are these couldn't find them in the haynes manual but then again i don't know what i'm looking for.

thanks again

[keithjreid]

I have been having similar problems, and have gone done the fuel contamination and ignition problems fault diagnosis.

Anyway I found the problem yesterday!

One of the vacuum hoses was perished. So I suggest you check the condition of all of the hoses going into the injection system.

[vitch]

thanks to everyone who's commented on this.....

took it to the place Stevemac suggested, in fact it's there right now.... J W morris....they noticed straight away that the inlet manifold had no bolts holding it together anymore and that there was no gasket there. This is definately a problem even if it's not the actual cause... have no idea why the bolts there have vanished, possbily due to the gasket perishing and casuing slack..

anyhow they've replaced the gasket, replaced the bolts and say it sounds like a different car.

Fingers crossed this is it.

thanks again everyone and especially SteveMac for all his effort.

[stevemac]

Nice one - hope they looked after you & fixed your car okay.[8D]

GS&F Mercedes Benz Product Manager   (Corrado G60)

[EmFen]

quote:Originally posted by vitch

Hi there all.

my cars been jumping recently when driving....it's ok through the revs and smooth as anything but as soon as load is going on, i.e i set of, then starts the judders. At first I thought it electrical so I re replaced the plugs (as silly motosave gave me ones with wrong offset) and the car was certainly smoother but still juddering. The leads are new and very good ones too. I even replaced the ignition coil from a friends dead rocco... It all started happening about a week to 2 weeks after i did a service...plugs dis. cap etc... i changed the fuel filter too (could it be this?). When it started happening i put back on all the old parts to see if any of the new ones were faulty but it still did this... the only thing i didn't put back on was the old fuel filter? From what i've been told they're not that complicated and not much can be wrong with one of these??

my feeling is now it is fuel related rather than electricl and I;m thinking the fuel pump is struggling... I am a little naughty with running the old rocco a bit low on fuel and wondered if this has damaged it? the fuel pump is just over 2 years old as when I bought it it wsa faulty (hence why i got it pretty cheap).. I was lucky then and just guessed it was the fuel pump causing the problems but now it's doing a similar thing again... I just want to make sure before buying another and paying for fitting as they aint cheap.

any help much appreciated.

Mark

Your mums hoover will go bang if you fill it with petrol fumes !
I have this problem once and used a speaker magnet to lift out all the rust and metal bits. I used a super glue to hold a loop onto the magnet. Glue dissolved, magnet dropped off and then all the glue on the magnet dissolved and caused real problems !!

[vitch]

Hi there all.

my cars been jumping recently when driving....it's ok through the revs and smooth as anything but as soon as load is going on, i.e i set of, then starts the judders. At first I thought it electrical so I re replaced the plugs (as silly motosave gave me ones with wrong offset) and the car was certainly smoother but still juddering. The leads are new and very good ones too. I even replaced the ignition coil from a friends dead rocco... It all started happening about a week to 2 weeks after i did a service...plugs dis. cap etc... i changed the fuel filter too (could it be this?). When it started happening i put back on all the old parts to see if any of the new ones were faulty but it still did this... the only thing i didn't put back on was the old fuel filter? From what i've been told they're not that complicated and not much can be wrong with one of these??

my feeling is now it is fuel related rather than electricl and I;m thinking the fuel pump is struggling... I am a little naughty with running the old rocco a bit low on fuel and wondered if this has damaged it? the fuel pump is just over 2 years old as when I bought it it wsa faulty (hence why i got it pretty cheap).. I was lucky then and just guessed it was the fuel pump causing the problems but now it's doing a similar thing again... I just want to make sure before buying another and paying for fitting as they aint cheap.

any help much appreciated.

Mark