Sluggish at low revs

[Guest]

Hi all,first post been lurking for a while though!
I have just got a 87 2.5s 16v (love it!), but it seems a bit dead low down. I have my suspicions it could be the fuel filter,the car has hardly done any miles over the past few years and it was awful at first,however a few runs have improved it no end along with fresh v-power!.
The symptons are similar to that of being out of petrol,i.e foot to floor produces not a lot of action,just spluttering and the revs dont pick up as you would expect a 4 pot 16v to....... Once its moving it goes well enough though,hence my thoughts of the fuel not getting through on full throttle settings.

Anyone experienced similar? I dont want to start ordering loads of bits if its something fairly common/simple.
Cheers in advance.

 

[Diver944]

I haven't driven a 2.5 16v but one of the criticisms was that it has no low down grunt (very common with all early 16v cars in the 80s as the manufacturers got to grips with the technology). The S2 addressed the problem by giving it a 3 litre engine.

If a car has stood for a while then it will need a good service - , fresh filters, oil, plugs and distributor cap etc

 

[Guest]

Its had a service with plug leads,back box,intake pipe and some sundries such as injector cleaner in december. I only got it this week though.
Its deffo a problem of some sort rather than a lack of torque by design,although I would be interested to see what one thats well sorted goes like for comparison!

 

[924nutter]

Having had a 944 16v I can say that yes it did lack the torque of the hugely torquey 8v engine and was at a disavantage up to 30mph in the 0-60 sprint against the 8v, but hit 3800 in second and it is almost like a 220 turbo coming onto boost, and you could rev that sucker up to 6800 before it hit the limiter so you could keep it on the boil if you wanted and few things were quicker when the revs were up. (Back in 1994)

Over the same distance, a standing start of just about half mile, speeds for my porsches were (are) in order of purchase
924 lux, 98mph
924 lux, (modifed cam) 103 mph
944 16v 110 mph
928 what was that white blur?
924 Turbo series 2 unbelieveably 112 mph
944 T cab feels the quickest of them all but I haven't bothered to try it out , its too nice to thrash like that.

 

[Paul Fraser]

I thought you could rechip the S to get better midrange torque, but that doesn't help with your suspected mechanical/electrical problem...

 

[Guest]

I had thought about a chip,however I am off to australia in 9 days for 2 weeks,then I am doing a track day a few days after getting back,so I havent got time to sort one really. It seems to pick up around 3k so its really only pulling away where its a problem.????

 

[Diver944]

<Paranoid mode on>

Personally I wouldn't subject a car to the rigours of a track day if there is a known fault. Maybe the dreaded camchain tensioner is so loose or the chain is so stretched that the timing is all to pot? [&:]

I've learnt to my cost over the years that when you continue to use something that you know is not 100% it generally becomes much more expensive to fix when you push it over the edge.

Why risk it? Get it looked at by a specialist now rather than when something breaks

<paranoid mode off>

Hate to be a killjoy

 

[peanut]

what you describe sounds very much like a fuel delivery problem. Non S2 944 might lack power at low revs but it should pull evenly from 1000rpm without any coughing or spluttering.

I would suggest you check the whole fuel delivery system.
Like you I have just had a similar problem which I'm convinced was caused by water in the fuel. Normally with plenty of fuel in the tank it gets burnt off but when the tank is empty and the car left for a while the water and fuel seperates . When water gets drawn up the fuel pipes into the filter/s it coats the filter material preventing sufficient fuel flow .I would recommend running the tank low then draining it completly.

Change the fuel filter and check that the fuel tank is breathing properly. I believe it draws in air through the filler cap to compensate for fuel used otherwise if blocked a vacumn is gradually created which inhibits fuel delivery at low revs.

My Mondeo LX currently suffers from this and when the tank is low it gradually dies. I remove the filler cap and there is a huge sucking noise as air is drawn in and off she goes again!

Next you might check that the fuel pressure valve is working correctly.(it is at the end of the fuel rail.) If it is releasing at too low a pressure that might give the symptoms you describe.

If it runs pretty normally at high revs then it is unlikely to be anything else and very unlikely to be a electrical problem I should have thought or you would experience poor running at higher revs also. Hope this is helpful

 

[Guest]

Cheers peanut,I will have a good look at the filter,I think it could have been caused by water or just from being stood. I want to get it sorted before the track day of course although the problem is not of the 'requires a specialist' type,I dont think. There are no noises that would suggest a belt/tensioner problem,although the timing ould be out as you say,it had new dizzy cap/leads etc at its last service,however that was at some random garage so they could have disturbed the timing.

 

[peanut]

any luck shuey ? did you get a chance to look yet ?
I was dead jammy with mine. I was loathe to dismantle everything so I just ran the stater motor continuously whilst the engine was partially firing . Eventually after about 2x minutes it had pulled all the contaminated fuel through and it started to fire properly. Lots of jiggling and juggling pumping the throttle and it finaly spluttered into life ![]

 

[sawood12]

When was the last time your fuel filter was replaced? It is often an overlooked service item. I get mine changed every other year as I've read our cars (all models) are sensitive to a clogged/loaded fuel filter. Not sure how true this really is but it's a cheap item so I tought that I might as well just to be sure.

 

[peanut]

yes its one of those vital little items that is easily overlooked when you think of servicing. I think I'll order one up for mine.[]