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        General >> Problems >> Scorpio 2.9 24v Cosworth - idle/low rpm problems
        
(Message started by: pappa on Apr 24^th, 2006, 11:58am)

Title: Scorpio 2.9 24v Cosworth - idle/low rpm problems
Post by pappa on Apr 24^th, 2006, 11:58am

Hi there fellow Scorpio owners/enthusiastics!

I recently purchased a Ghia spec -96 Cossie. The car has
initially been registered to Germany and has been imported
into here (Finland) about two years ago. I traced back the
previous owner and he verified that the 142.000 km on the
clock should be correct.

I'm suffering from poor idle + "jerky" ride when cruising at steady
speeds. When the speed rises above 100km/h (sorry guys,
we're using km's instead of mp's up here) the problem is
not so bad, but you can feel it's in there. If I switch the
autobox to 'S' it seems to help?!

I have cleaned the MAF, just to be sure. The problem
must have been there for a while, because someone
had put a fuel filter into Pressure Tranducer EGR hose
plus pplugged one of the hoses leading into somewhere
into the general direction of the EGR.

My temp gauge never shows higher readings than half,
but it slowly greeps it's way there when the engine is
getting hotter.

Yer.. and sure enough, no battery cover (but no mysterious
electric problems and we surely get our share of water
in the form of snow and water up here)

I really love the car despite it's "things" so I take a
deep bow and thank for the authors of this magnificant
web-site!

Title: Re: Scorpio 2.9 24v Cosworth - idle/low rpm proble
Post by Highlander on Apr 24^th, 2006, 4:47pm

Hi and welcome to the site :)

The Maf may not be working, can you check it with a known working unit?

Does it make a difference if you disconnect it?

Title: Re: Scorpio 2.9 24v Cosworth - idle/low rpm proble
Post by Matt on Apr 24^th, 2006, 6:58pm

I disconnected my maf sensor the other day and started the car mainly just to see what would happen, but i noticed that the engine seemed to be 'searching' for it's idle point e.g. revs would rise and fall continually (from 750 to 1500 rpm marks) but that was with the car stationary. If your car does the same then Highlander may will be correct. Ive not owned mine long enough to know the scorps little querks but hopefully this helps

Title: Re: Scorpio 2.9 24v Cosworth - idle/low rpm proble
Post by pappa on Apr 25^th, 2006, 5:50am

Hi guys!

Thanks for the tips. I'll disconnect the all mighty MAF today and give it a try.
I'll post the results.

Yesterday I cleaned up the IAC valve and put some silicon glue into
a joint of a vacuum pipe leading into the brake "booster". That was
obviously loose and would leak extra air into the manifold. Did not
have time to test the car after these fixes, but today...

Later... 8)

Title: Re: Scorpio 2.9 24v Cosworth - idle/low rpm proble
Post by pappa on May 23^rd, 2006, 9:55pm

Hi there!

Took a while to get back here, but here I am. Yer... Sure enough, removing the MAF
multiplug revelead that it does nothing. But I have another theory: a clocked catalysator!
I took my darling cossie to local Ford for the timing chains change operation and while
they were at it, they found out that at least one cat is clocked. It has overheated a few
times and partially melted the petrol lines... :-/
NOT very nice. A new CAT (genuine ford part) would cost 700 euros - :o
So I decided to order TWO no-name CAT's at 82 euros each. I need to do some
minor adjustments :-X (sawing, fitting and welding ) to get them in there.
After that, we'll see if the problem still persists. A lot of work ahead, but a good
thing is that I do like my Cossie...

Thanks, I'll keep posting...

Title: Re: Scorpio 2.9 24v Cosworth - idle/low rpm proble
Post by Dave on May 24^th, 2006, 9:20am

Good luck with it.

Let us know how it goes!

Title: Re: Scorpio 2.9 24v Cosworth - idle/low rpm proble
Post by pappa on Jul 2^nd, 2006, 7:24pm

Hi again!

Ok - I finally got my beast back from the Ford Dealer. It took 1 month + 10 days
to get the timingchains renewed :o It took more than a month to get the parts!?

Bloody ****. Well they did a very good job with the car, I'm very satisfied but the
original problem had nothing to do with this major overhaul. The car is still a
jerky thing to drive and I had already purchased a new pair of CAT's to put
in. CAT's I've purchased are not orginal parts.

I'm now in the middle of recreating the catalysator. That's bit of task I'd say :-/
but I'm slowly getting there. I've taken a pile of digital photos of the project
and will (when I have the time) write an "article" about it.

I can then post a link for you to read. I'll do it in english. ;D It'll be quite a
lot easier for you guys to read than finnish...

And some news on the project:
There are four lambda's in that car and at least one them is rattling, one
catalysator was emptied some time ago and one totally clogged :-/
So I'm not wondering why it's not running perfectly smoothly ;D
Thinking about the poor ECU, trying to figure out how to fine tune the
amount of petrol + air with the data it gets from this mess, makes me
want to cry. They used to make really good parts back in the 90's !
The catalysator walls must at least 3-4 millimeters thick! Phew! Real
metal! That is something you don't find in your -2005 TinCan...
My apologies to all TinCan owners - it's been a long day. Maybe I turn in
for the night.

Catch ya later... Have great summer! 8)

Title: Re: Scorpio 2.9 24v Cosworth - idle/low rpm proble
Post by pappa on Jul 8^th, 2006, 8:13am

Allright then!

New catalysators are in place an so are the new rear lambdas.
Quite a task I'd say. But it helped, the car is still "hesitating" and
slightly jerky, but it's now tolerable :-/

But... fix one problem and get another one to wonder about. It
seems that I've lost a significant amount of torque at low rpms ???
I need to give it a good kick and lot of revs to get the power out.
On low rpm the car is sluggish and that's not the way it's been.

It has gone through a major overhaul:
Timingchains + all the parts in there, autobox oil + filters - some wiring
was fixed (partially melted) and original catalysators removed + rebuilt
exhaust system from exhaust manifold to the center muffler (which I
removed). I also replaced the rear lambdas.

So here we are. Another call for help: What could cause the loss of
torque? (million reasons I suspect)

Does anyone have an idea on the lambda wiring? Original lambda wires were:
2 White, 1 black and 1 grey wires. In the new lambda I have 2
black (heater), 1 blue (signal) and one white (gnd). I connected
the 2 black ones into the original 2 white ones, the blue into the
original grey and the white into the original black. This could
be the reason, if the wiring is incorrect...

Title: Re: Scorpio 2.9 24v Cosworth - idle/low rpm proble
Post by fordcos on Jul 8^th, 2006, 8:18am

hi have you tried disconnecting the battery for 30 mins to allow the computer to relearn

Title: Re: Scorpio 2.9 24v Cosworth - idle/low rpm proble
Post by Meg on Jul 8^th, 2006, 8:40am

hi-wiring blue =signal prev black
white=earth prev grey
black=heater prev white
for replacment sensor.HTH

Title: Re: Scorpio 2.9 24v Cosworth - idle/low rpm proble
Post by pappa on Jul 8^th, 2006, 9:04am

Hi!

Thanks! Nope haven't re-educated it yet and Thanks Meg,
my wiring sucks... signal / earth are mixed :-/

Have to fix that, then re-educate the car...

Title: Re: Scorpio 2.9 24v Cosworth - idle/low rpm proble
Post by pappa on Jul 10^th, 2006, 6:01pm

Hi!

Ok, fixed the lambda wiring and let the car relearn. Still having the jerky-jerk
in the engine. I ordered OBD scantool + software and try to pin point me
into right direction. Someone said that MAF may not be working, that is
an option yet to be tried.

I'll keep on testing and tuning, it runs better now, but that annoying jerk
still persists. It could also be the EGR, but I would not like to plug it...
There's power now and low rpm torque got a lot better. It's a 8) to drive.

OBD enthusiastics, have a look at: www.omega.fi - they sell scantools +
software. I'll post my experiences on that when I get it.

Title: Re: Scorpio 2.9 24v Cosworth - idle/low rpm proble
Post by Highlander on Jul 10^th, 2006, 11:31pm

Pappa I have a known working MAF I can post to you to try if it helps.

Title: Re: Scorpio 2.9 24v Cosworth - idle/low rpm proble
Post by arnse on Jul 14^th, 2006, 1:00am

Hei Finland,
Hvordan går det med Scorpioen?
Jeg har en lik i Norge med samme problem, du kan ta kontakt direkte på email om du vil. Jeg har erfart mange av de samme problem som du nevner, er klar for en kunnskaps-utveksling.
Mvh
Arnfinn

Title: Re: Scorpio 2.9 24v Cosworth - idle/low rpm proble
Post by pappa on Jul 14^th, 2006, 5:57am

on 07/10/06 at 23:31:24, Highlander wrote:

Pappa I have a known working MAF I can post to you to try if it helps.

Hi Highlander!

Thank you for your kind offer, I appreciate it.
I have a Ford guru in a town nearby and he has a MAF
+ electrics from an older Cosworth. What do you think,
could that work with the -95/96 model? It's from the
194 bhp engine. He wasn't 100% sure.

Anyway I will get the scantool which gives me the access
to the engine data - I should know more after I've tried
these options.

But if all else fails, I would be interested in your offer
and of course willing to take care of the expenses of
mailing etc.

I'll keep in touch, thank you very much for your help.

Title: Re: Scorpio 2.9 24v Cosworth - idle/low rpm proble
Post by pappa on Jul 14^th, 2006, 6:01am

on 07/14/06 at 01:00:56, arnse wrote:

Hej Arnse,

Tackar!

Jeg förstår inte Norge och min Svenska är mycket dåligt
också. Är det möjligt at skriva på engelska?

Same in English:

Hi Arnse,

Thanks!

I do not understand Norweigian and my Swedish is
very bad too. Is it possible to write in English?

Title: Re: Scorpio 2.9 24v Cosworth - idle/low rpm proble
Post by pappa on Sep 18^th, 2006, 2:36pm

Hello!

It's me again, after a long break. I've got something new on my jerking Cossie.
I finally got the right equipment to analyze my OBD II data and it says:

p1131
p1151

And to sum that up, it means that lambda's are busted right!?

I quote the macnifigant Ford-scorpio web-pages:

P1131 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 1.

P1151 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 2.

Just to make sure, I reckon these are the ones that are BEFORE the catalysators?

For those who are interested, I purchased ElmScan5 OBD-II scanner from a Finnish dealer. The original werb-site for those is: www.scantools.net

It works!

Title: Re: Scorpio 2.9 24v Cosworth - idle/low rpm proble
Post by pappa on Oct 2^nd, 2006, 8:14am

Howdy!

Well, well, well... I took a chance and replaced my oxygen sensors
(pre-cats, I've already replaced after cats earlier) and DTC's disappeared
plus jerking reduced dramatically.

So it turned out that the sensors were failing, but there is still something
I can't quite get a grip. It's fairly good now, but at low cruising speed it
still is jerking plus idle speed is sometimes 1000 to 1200 rpm and sometimes
aroun 800 rpm. There are no starting issues, car starts beautifully.

I have a OBD Scanner which can produce a lot of data on different sensors,
but it seems that Vehicle Explorer cannot read it. I have other software to
use, can someone give me some advice on what to monitor? Are there
some specific test runs that could be done and collect the data while at it?

Thanks!

Title: Re: Scorpio 2.9 24v Cosworth - idle/low rpm proble
Post by pappa on Dec 6^th, 2006, 11:01am

Jerking sorted all together!

Plugged the EGR upper hose and no more jerky ride for me!

Next idle problem to sort: RPM staying high (1500 rpm) after
driving.

Potential cause:
- Sticking IAC valve ?
- Bad throttle position sensor ?

Comments are welcomed.