Low on fuel, stuttering ?

[J4CKO]

My S2 was a bit low on fuel tonight, would it cause any stuttering or anything, it was on the red line, I was thinking it would suck up air and deprive the engine of fuel, is this a common trait and it just needs fuel or could it be something else, light wasnt on (assuming they have one) also noticed it ws hunting a bit at idle.

 

[Frenchy]

Hunting on tickover points to an airleak.

 

[J4CKO]

Where is likely Frenchy ?

 

[944Turbo]

fill it up and see if it goes away? I guess there is some gravity feed effect from a full tank so maybe if the fuel pump is tired or has a bad connection in its circuit somewhere or restricition (dirty filter) it may get worse at low levels

 

[J4CKO]

The Fuel Filter is ancient and is on my list of jobs, will order one today.

Will fill it up, tried to last nigth but the station was closed, being refilled from a tanker.

Think I need to get a fuller understanding of how the fuel and ignition hangs together.

 

[924nutter]

Embarrassingly, I had my 928 trailered off the M40 due to loss of power. The engine would run and idle but no pulling power. The red fuel light was on. I had it trailered to Northway, who put a gallon of fuel in it and away it went. Like 944 man said, put some petrol in it, it'll only cost you a fiver to find out.

 

[944 man]

Much as Id like to have said: "fill it up soft lad!", that advice came from Tony... []

 

[Veerzigzag]

Just a comment: the low-fuel light does not show when switching the ignition on, so you could have a blown bulb and not know. My low-fuel light (a critical item when my family are using the 944) was intermittent and usually came on about 10 feet from the car running out of fuel. I stripped the sender unit (a beautiful and delicate piece of engineering) and found that the two contacts that switch the light on had got slightly bent upwards over the years; this meant that the float bottomed before the switch made proper contact. Carefully straightening them with tweezers solved the problem.

 

[J4CKO]

Yeah, will fill it up, it was just I coudltn get any and I have noticed it has been a bit strange the last couple of times I have been out in it, I do think it is fuel level related as it is quite low, was kind of wondering if anyone else has had similar issues when running low on fuel.

I tend not to fill it to the brim, I put like sixty quids worth in, always at the back of my mind that I may need to drain the tank to do the fuel lines, it may be stood for a while and also that is a lot of fuel in a realtively small car, a full fill is like £100 as well.


Fuel filter ordered, looks like it may be a fun job, upside down trying to extracate the old (crusty) one whilst it drops unleaded on your head.

 

[Veerzigzag]

was kind of wondering if anyone else has had similar issues when running low on fuel

Mine runs perfectly until the last half-mile so you probably have another problem.

 

[vitesse]

Fuel filter ordered, looks like it may be a fun job, upside down trying to extracate the old (crusty) one whilst it drops unleaded on your head.
[/quote]

You know what to do-arrange to run out of fuel just as you arrive home-then the filter will be empty.[]

Or /And use hose clamps plus kitchen towel.

 

[Hilux]

Fuel filter ordered, looks like it may be a fun job, upside down trying to extracate the old (crusty) one whilst it drops unleaded on your head

I highly recommend you get under there and brush off surface rust and get plenty of penetrating oil such as 'Plusgas' on the filter unions (WD40 isnt penetrating oil) well in advance of the job or you could be into a big job replacing hoses. Take care you dont strain the hoses when undoing as they are probably a bit brittle if original.

 

[J4CKO]

ORIGINAL: Hilux

Fuel filter ordered, looks like it may be a fun job, upside down trying to extracate the old (crusty) one whilst it drops unleaded on your head

I highly recommend you get under there and brush off surface rust and get plenty of penetrating oil such as 'Plusgas' on the filter unions (WD40 isnt penetrating oil) well in advance of the job or you could be into a big job replacing hoses. Take care you dont strain the hoses when undoing as they are probably a bit brittle if original.

Yep, am ready for a battle, Plusgas already on there, failing that will get the blowtorch on there and get some heat into it.
























Im joking about the last bit btw

 

[Frenchy]

Let us know how you get on, BTW my fuel light comes on in plenty of time, i could probably get 50 miles out of it but have never tried it though []
The little bobbins that hold the filter to the body brackets via the clips are usually buggered £10 each from OPC or a bag of 10 similar jobbies that will do from RS Components around a fiver.

 

[J4CKO]

Well putting fuel in didn't help, so will change the filer, after that, what else can cause it, coil, leads, afm, air leak, sensors etc, is there a cheap order to do it in, it isn't all the time, very intermittent, will idle perfectly for ages then stutter, most time on throttle it's fine and pulls as well as an S2 has any right to, and then, occasionally it starts bucking, back off the re apply throttle and it's fine, I thing the oily bits are fine so it's fuel or ignition/electrical.

 

[J4CKO]

Just tried to take the fuel filter off to change it, one side was fine, the other, no chance, thought I had got it but it just rounded, will need to replace the bit of pipe it connects to, how much of a job is that ?

Then, I managed to chip the front arch with an axle stand.

Think its this I will need to buy,

http://www.rosepassion.com/en/cat/porsche-944-1991-944-s2-cabrio-manual-gearbox-5-speed/M454/engine-and-fuel-feed/fuel-filter-fuel-pump-fuel-accumulator-tank-fuel-pipe/B2281/fuel-system/I4810/fuel-line/P40276

Can anyone confirm that is the correct line for drivers side end of the fuel filter ?

Is the metal cover that it goes into easy enough to remove ?


Have tried a new DME Relay

And have took the AFM plug off and on and put a it of WD40 on it as apparently that can be the issue.

 

[J4CKO]

Still the same, seems heistant as well now.


Dont think its the fuel filter it manages full throttle fine

Is it worth me opening up the AFM and having a look at the tracks, anyone tried it, how hard is it to do, my gut feel is a worn AFM, anyone got a known good one to sell, I dont want to change everything so will do it in cheapest order

Other things to change/look at

Fuel filter (tried/failed) - Dont think so

Injectors - Again, they work ok at full throttle so unlikely

Plugs - Possible, not sure when last change, will check service history, I havent done them but I dont do much mileage.

Leads - Look ok, possible

Fuel Pump - Apparently they dont fail that often, possibly wiring ?

Coil - Dont think its ever been changed, not sure of the failure mode of a coil

Crankshaft Sensor - D

Knock Sensor - Unlikely

Rotor Arm ?

Dizzy Cap ?

Ignition whatsit on the inner wing - Possible

Idle Control Valve - Unlikely, these dont seem to fail generally from what i have read.

Fuel Pressure Regulator - Possible

Lambda Sensor was done last year - Dont think it would cause this

DME Relay - Changed for new one, still the same

Air leak - possible but wouldnt it occur all the time ?


Could do with a Spare S2 so I can swap bits across !


Have I missed anything that could be causing it




People are offering a rather expensive MAF for the S2, er, correct me if I am wrong but itsnt that 15 quid part that hasnt been integrated with the DME ?

http://www.ebay.co.uk/itm/Bosch-Air-Flow-Meter-Sensor-AFM-Variant1-Genuine-Direct-Replacement-/190789015703?pt=LH_DefaultDomain_3&fits=Model%3A944|Cars+Type%3A3.0+S2&hash=item2c6be95897

 

[eddieedmo]

have a look at Clarks Garage website there is a link to a site which details how to fix an AFM.
I opened mine up awile ago but couldn't reposition the contacts od the swept area because it had 3 points of contact , not 2 as described in the link.So I got a used one from a 92 low mileage S2 and the car is much smoother now , no hesitation which was there at times.Mine had done 176k miles , so well used.

Nick

 

[944 man]

ORIGINAL: J4CKO

Well putting fuel in didn't help, so will change the filer, after that, what else can cause it, coil, leads, afm, air leak, sensors etc, is there a cheap order to do it in, it isn't all the time, very intermittent, will idle perfectly for ages then stutter, most time on throttle it's fine and pulls as well as an S2 has any right to, and then, occasionally it starts bucking, back off the re apply throttle and it's fine, I thing the oily bits are fine so it's fuel or ignition/electrical.

All of that stuff could be the cause... Id opt for a new DME relay first. The DME 'relay' is actually two relays inside one box. It powers the DME/ECU on ignition and the fuel pump on the control signal from the DME. Either relay can fail in any number of ways and combinations. The fuel pressure regulator is becoming the new DME relay too and even though it costs around £100, Id still regard it as money well spent, because even if it wasn't failing, then you have probably headed off a future break down.

 

[J4CKO]

Tried the new relay, like any 944 owner should I bought one and stufff it in the glove box,

There are several AFM's on Ebay for £40 or so, I dont want to buy knackered old crap or just throw money at the issue willy nilly as I have been apt to do in the past.