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General >> Problems >> Another Scorpio with fueling problems...
(Message started by: Marc1978 on Oct 16th, 2011, 1:23pm)

Title: Another Scorpio with fueling problems...
Post by Marc1978 on Oct 16th, 2011, 1:23pm
Hi everyone, my Cossie has developed a fueling issue over the last week that has now got to the point that I can only manage 130 miles from £50 worth of fuel. Basically, regardless of gear, if you hold the revs wherever you choose, the car begins to run very unevenly, but if you take your foot off the throttle pedal it runs fine and if you push down hard and accelerate, it also runs fine and there's no issue when idling. Just seems to be an issue when trying to hold a constant speed. Also, when you get out after a run, there is a strong smell of petrol and grey smoke coming out the tailpipe.

I cleaned the MAF and there's been no difference and the only other thing I've done is removed the cats but that was three months ago and it ran absolutely fine and even remained inside the emission requirements when it went for MOT.

The only thing I could think of was the TPS might be up the duff but before I start messing around with sensors or start looking for someone with a diagnostics machine, I figured I'd ask the experts here first :-)

Title: Re: Another Scorpio with fueling problems...
Post by amigafan2003 on Oct 16th, 2011, 2:37pm
Get it scanned and emissions tested - sounds like one or both of the pre cat Lamda sensors has gone and it's running rich.  You say you removed the cats - I assume you refitted the sensors?

It's worth noting when lambda sensors fail and go open circuit they indicate lean - making the ecu wanting to add more fuel (it's safer to add than remove it for an engine).

Title: Re: Another Scorpio with fueling problems...
Post by Matt on Oct 16th, 2011, 2:43pm
Hi Marc

Hows does it run say day to day? does it seem like your ECU is going into loss mode?

BTW Marc's car has been converted to manual transmission  ;)

Could your clutch be slipping a bit? Still got the Hydrogen kit on it?

Title: Re: Another Scorpio with fueling problems...
Post by Marc1978 on Oct 16th, 2011, 7:25pm
All the sensors have been plugged back in as before so nothing's changed on that front. The clutch is fine and not slipping whatsoever and the hydrogen kit is wired in but I haven't set it up yet as the car isn't running right for me to sort out the mix properly.

Day to day it's been fine. Smooth and quiet so I don't think the ECU feels like it's gone into loss mode. Who best can run a scan on the diagnostics machine as I have a friend who runs a local garage who has the IT kit to do checks on most cars, so will that do the job?

Just a quick update, I disconnected the TPS to see if that made a difference and the car behaved in exactly the same way.

Title: Re: Another Scorpio with fueling problems...
Post by Matt on Oct 16th, 2011, 9:08pm
Hi marc

your mate with the scan kit would be the best bet, might not throw up the auto box prob if its not FDS

BTW remember superchips said you cant run the scorpio on a v6 mondeo ecu, well heres mine doing just that!!

http://www.youtube.com/watch?v=B7es4yYRQGA

Not perfect yet as theres a few kinks to iron out but its very possible

Title: Re: Another Scorpio with fueling problems...
Post by Marcello on Oct 16th, 2011, 9:14pm
Well I'll be d**ned lol...

I pulled my ECU out to find the stupid thing had a different plug so wouldn't fit.

How did you get yours wired up?

Title: Re: Another Scorpio with fueling problems...
Post by Matt on Oct 16th, 2011, 9:57pm
Its running on a mk2 st200 ecu, both scorpio and mondeo use eecv so plugs are the same, both cars even have the same pats units.

You need to swap some wires about within the plug though as you can see i made an adaptor so its plug n play untill i can sort it all out fully

Title: Re: Another Scorpio with fueling problems...
Post by Marcello on Oct 16th, 2011, 10:16pm
Sounds straightforward enough but given all the hassle I've been having with sensors, I'm going to go down the Megasquirt route instead and do away with the lot. That way, it'll be me versus the engine :-)

Title: Re: Another Scorpio with fueling problems...
Post by Marcello on Oct 18th, 2011, 8:26pm
Hi all,

I ran a diagnostics check and four error codes came up:

P0122 Throttle Position Sensor circuit Low Input.
P0131 Upstream Heated Oxygen Sensor circuit out of range - Bank No. 1
P0161 Downstream Heated Oxygen Sensor Heater circuit fault - Bank No. 2.
P1131 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 1.  

The last three are obviously cat related, but what would be the ideal fix for the first one for the TPS?

Thanks.

Title: Re: Another Scorpio with fueling problems...
Post by Mike H on Oct 19th, 2011, 1:27pm
As a guess if TPS is duff, replacement. Is like a wirewound variable resistor I believe and the wire can break or wear away. But also make sure it's not as simple as a bad electrical connection.

Title: Re: Another Scorpio with fueling problems...
Post by Tompion on Oct 19th, 2011, 3:07pm

on 10/16/11 at 19:25:34, Marc1978 wrote:
Just a quick update, I disconnected the TPS to see if that made a difference and the car behaved in exactly the same way.

The code may be left from when you disconnected the TPS.
Depending on the code reader you may be able to see if the TPS works/works smothly as you push the throttle - key on engine off.

Details of the TPS here:
http://www.fordscorpio.co.uk/tpsdata.htm

Title: Re: Another Scorpio with fueling problems...
Post by amigafan2003 on Oct 19th, 2011, 4:08pm

Quote:
P0131 Upstream Heated Oxygen Sensor circuit out of range - Bank No. 1  
P1131 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 1.


There you go - dodgy pre-cat lamda sensor - reading lean - as I said in the 2nd post of this thread.  If you check your long term and short term fuel trims they'll be way up in the "+" range - probably +10 for long terms and to +20 for short terms.


Quote:
P0161 Downstream Heated Oxygen Sensor Heater circuit fault - Bank No. 2.  


You can ignore the post cat lambdas - they are just there to monitor the cat performance - as Scorps don't have a mil light you'd never know it reporting a cat fault unless you scan it anyway!


I concur wit Tompion re the TPS code.

Title: Re: Another Scorpio with fueling problems...
Post by Marcello on Oct 22nd, 2011, 12:36am
Hi guys,

I took the TPS plug to bits and cleaned it up. To make sure it was making a good connection I cable tied the plug as well and the fault has disappeared. As for the cats, I figured that one out as well now. The hydrogen that's passing through the fuel is creating less carbon particles from the combustion cycle so as the fuel is now being burned more efficiently, less is being used thus tricking the ECU into thinking that the engine is running lean. Disconnect the hydrogen feed and the problem vanishes. So all I need to do is bypass the pre cat sensors and we're fixed. So a new custom ECU will be the order of the day now. Oh and for your info Matt, I ran the car to Heathrow and back and averaged 36mpg with fuel only and with the hydrogen feed switched on, got the other side of 40mpg out of it. Still, with the sensor readings sending the engine into shut down mode, it'll have to be petrol only for now.

While I wait for the ECU, a new problen has appeared. The temp gauge all of a sudden jumped into the red while in traffic even though I was only stood for less than 30 seconds and as soon as I pulled away, it dropped back down again to normal. It then continued to flick between the two for a while before settling back down again. Any ideas on what to look at first guys?

Title: Re: Another Scorpio with fueling problems...
Post by Simmo on Oct 22nd, 2011, 7:37am

on 10/22/11 at 00:36:07, Marcello wrote:
While I wait for the ECU, a new problen has appeared. The temp gauge all of a sudden jumped into the red while in traffic even though I was only stood for less than 30 seconds and as soon as I pulled away, it dropped back down again to normal. It then continued to flick between the two for a while before settling back down again. Any ideas on what to look at first guys?

A water leak or low coolant level.

Title: Re: Another Scorpio with fueling problems...
Post by Marcello on Oct 22nd, 2011, 9:28am
Hi Simmo,

I checked for leaks and there are none and the coolant level is exactly where it always has been. Thanks.

Title: Re: Another Scorpio with fueling problems...
Post by Mike H on Oct 22nd, 2011, 11:11am
Has it been drained & refilled lately? You can have air in it (air lock) and header tank level will still look correct. Going by other topics on this subject, temp gauge symptoms suggest that to me.



Title: Re: Another Scorpio with fueling problems...
Post by Mike H on Oct 22nd, 2011, 11:14am
Or, could be dodgy temp gauge wiring


Title: Re: Another Scorpio with fueling problems...
Post by Marcello on Oct 22nd, 2011, 11:58am
This is a weird one as I've left the car idling for 45 mins now and the guage is reading bang on halfway and hasn't twitched. The fans have cut in and out so they appear to be working normal. Only thing I've noticed is the heater is blowing cold when on HI so maybe there is an airlock in it somewhere. Will try flushing the air out in a minute and let you know how I get on.

Title: Re: Another Scorpio with fueling problems...
Post by Mike H on Oct 22nd, 2011, 1:24pm
Again going by other topics I've seen lately, heater cold, fans going on and off, sure sign of air in the system. See Jonnycab's topic in 'How To Do Things':

REMOVING STUBBORN AIRLOCKS from cooling system

http://www.fordscorpio.co.uk/cgi-bin/yabb/YaBB.pl?board=admin;action=display;num=1267895712

24V's seem prone to it, or that's my impression anyway



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