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        General >> Give/Need advice to/from others >> Throttle Surge
        
(Message started by: pinto on Apr 20^th, 2009, 10:42pm)

Title: Throttle Surge
Post by pinto on Apr 20^th, 2009, 10:42pm

Happy boy with my new cossie ;D

Just a question for those who own/have knowledge of the 24V (cos im learning lol) on the journey home, i noticed a gentle pulsing surge under light throttle - it dissapeared on opening her up - and a little indecisiveness with the gearing under load sometimes (she labours up hills sometimes)

She also doesnt quite seem to have the punch i'd expect over and above the 16v 2.3 that im used to - seems to be holding back on light throttle.

Im thinking MAF ?

Any advice ? :)

Title: Re: Throttle Surge
Post by Highlander on Apr 20^th, 2009, 10:56pm

MAF for starters,
new plugs can make a big difference if its running on old broken ones.

Best bet is a scan and see what you can see.

Its amazing how many vaccum pipes etc get put back the wrong way ;) might be worth checking them, there is a guide on the main site i think.

I once had a look at TinTin's 24v when it wasnt running great and the last garage that had worked on it (professional car garage) had put the idle control valve on backwards!!
I was looking at the engine and knew something wasnt right but it took me a good while to realise what it was :)

Title: Re: Throttle Surge
Post by Tons_of_fun on Apr 21^st, 2009, 8:43am

Hi Pinto. The symptoms you have just described were exactly how my cossie was a couple of weeks ago. My M A F was absolutley filthy, so after a good spraying with carb cleaner it now runs brilliantly. HTH

Title: Re: Throttle Surge
Post by amigafan2003 on Apr 21^st, 2009, 9:05am

I did clean the MAF when I got it but that was back in Sep 2007 so maybe worth doing again? It also had new plugs and leads at the same time - some people change them every year - others dont - pull a couple out to see what they look like. I've never put injector cleaner in it though - might be worth chucking a bottle of redex through it.

Can't say I ever noticed what you are describing - in fact the y reg feels exactly the same which leads me onto my next points:-

Economy mode on the gearbox will "hold" onto gears for longer - meaning that it takes a bit more throttle than you expect to make it shift down. Sports mode will make the box shift down earlier.

Also, bear in mind the VIS "lag" on a 24v - it can feel like a flat spot.

http://www.fordscorpio.co.uk/flatspot.htm

Quote:

She also doesnt quite seem to have the punch i'd expect over and above the 16v 2.3 that im used to - seems to be holding back on light throttle.

I don't think there is any difference on light throttle tbh - it's not until med throttle / WOT that the Cosworth makes it's presence felt :-)

Title: Re: Throttle Surge
Post by pinto on Apr 21^st, 2009, 6:17pm

Yeah, i was thinking MAF, simply because its exactly how my 2300 was acting with a dirty sensor - dose of brake cleaner and she was a lot crisper :)

I'll dose the MAF and see if it helps, then try the plugs and leads (the price of those arent nice tho lol )

Title: Re: Throttle Surge
Post by tonyboy on Apr 21^st, 2009, 7:24pm

Hello all. excuse my ignorance but whats a MAF ? P.S. I don't know a lot about cars .

Title: Re: Throttle Surge
Post by Highlander on Apr 21^st, 2009, 7:41pm

Mass Air Flow sensor, it measures the air intake into the engine and uses that measurement to adjust the running of the engine/gearchanges on an auto etc.

If you look under the bonnet of your 24v its on your right side near the front, just where the air comes out of the air filter, a metal cylinder with a multiplug and wires coming out of it.

http://www.fordscorpio.co.uk/images/24vmaf.jpg

The diesels and the 12v's dont have them ;)

Title: Re: Throttle Surge
Post by pinto on Apr 21^st, 2009, 8:33pm

Well, i took it to my brothers garage and plugged it into our V-Spec, but it pretty much revealed its hand on the way up :)

Surging, running badly and just would not rev, even on kick down. Add to this, nooo power regardless of how much the loud pedal was pressed....

Scan revealed two fault codes:

HGS02 Switch fault - reports running lean
HGS02 Switch Fault - reports running rich

looks like the poor ol' rattly right cat didn't think much of a 390 mile motorway run at the weekend and im guessing has partially collapsed :) - also explains a lot of the running issues IMO. Im guessing the two opposing codes meant that the left bank was running rich to try and compensate for the right bank lean reading ?

Just ordered a new cat from www.buypartsby.co.uk - £63.83 + VAT was pretty good ;D

Title: Re: Throttle Surge
Post by Simmo on Apr 21^st, 2009, 8:52pm

Hope you get it sorted Geoff. Good luck and look forward to seeing the car soon. Mike. :)

Title: Re: Throttle Surge
Post by pinto on Apr 21^st, 2009, 8:59pm

Cheers mike :)

whens the next Badgers Shindig planned for ?

Title: Re: Throttle Surge
Post by Simmo on Apr 21^st, 2009, 9:42pm

Should be the end of May so watch the meetings page. ;D

Title: Re: Throttle Surge
Post by amigafan2003 on Apr 21^st, 2009, 10:33pm

Ah, that would explain it. I thought you'd have got more out of the cat as they can run witha rattle for ages but sometime they do just go.

Not a hard job to change the cat - just get the manifold gaskets in case the manifold needs to come off due to snapping a stud. Remember to get a manifold>cat gasket as well. If you do snap a stud, angle grind it flush and drill it out SLOWLY with a 9mm HSS drill bit and just nut and bolt it back together.

Title: Re: Throttle Surge
Post by amigafan2003 on Aug 6^th, 2009, 1:38pm

Dredging up an old thread but how did the new cat fitting go?

Title: Re: Throttle Surge
Post by pinto on Aug 7^th, 2009, 12:48am

All done and dusted, although im hoping to get an answer soon on the ashley/decat :)

Still surges a little - thinking on replacing the MAF next