Have an 88 S2 which is costing me a fortune in fuel just now due to slightly poor running, has an intermittent lack of boost as well.

Have a boost gauge fitted and usually boosts to around 1 bar but will sometimes drop to around 0.7 or 0.8 and feels like its holding back, get the occasional back fire as well and sometimes on full boost the turbo really whines !

It seems to be running quite rich as lots of black at the tail pipe, never actually splutters though and starts and idles perfectly, cold start is currently disconnected and has been since i got the car.

Am having to use the car daily just now for work which is only a round trip of 20 or so miles and its costing a fortune in petrol so wondering what possible problems i need to be looking for ??

Have not had time to have much of a look at it yet due to working long hours just now so am hoping for a quick and easy fix as will have to looked at outside in the dark and cold !!!


Any help greatly appreciated folks.



Fully expecting to be told it could be a multitude of things wrong !!!

 

Depending on where you are in Scotland I'd take it to Sitech Racing and get it checked over and set up. That'll help no end

 

Im in scotland too, my money is on a boost leak or dumpvalve problem, probably the dump valve sticking open as its never been serviced? would also benefit from a co check and ignition timing check. you sould get upto 30 mpg from it

 

30mpg. I wish. I have never betered 18mpg driving nice in any of my rs. Even my efi one was Shit.

 

My old s2 1800 zetec turbo used to do 35

 

If the turbo is whining then it could be on its way out, have you checked it for play?
Factory MPG was 28 so a RST running higher than stock boost will be terrible on fuel.
Your ZT chaffe will of course be miles better on fuel as the Zetec has a much lower BSFC and was EFI I'm guessing.

 

lol yeah, was on MS and was about 17:1 afr on cruise, and it had a diesel MTX75 with intergalictic fith gear. But even when it had the 1600 cvh on mfi it wasnt too bad on fuel

 

Used to get just over 30mpg from my S1, full stainless exhaust, slightly raised boost pressure but otherwise standard. Depends on how they are driven, maintained and set up to be fair though. As suggested get a dcent tuner to have a look around the fuel and ign systems for problems and get it set up.

 

lmao excellent!

 

Should have mentioned its running standard boost as far as im aware and only mods from standard are bailey dump valve,cone filter and stainless exhaust.

Have not yet checked turbo wear and freeplay, the emissions were on the high side when it was mot'd but its not running that rich that it floods itself or makes it difficult to start as always fires up with a flick of the key everytime.

Will check the turbo impeller for wear and maybe remove the dump valve if they are prone to cause problems.


Sitech is a 5hr drive from me so want to have a go at sorting this myself if possible, have heard good things about them though and maybe have to head there at some point for a set up but rather spend a wee bit of time on it myself first.

 

Theres your problem, its clearly "chocked up" and in need of 20 psi to clear its throat.
In all seriousness, remove and blank the dumpvalve and its wee pipe and see how you get on.

 

You said it's running 1 Bar, thats double standard boost mate lol
It must also be chipped at that boost too.
As I said check the turbo shaft for play and get it to a tuner for a fuelling and timing check it's the quickest and easiest way to diagnose your probs without risking your engine.

 

I usually get between 20-25mpg, I know not nice.