131mirafiori forum

I've had a running problem with my Sport since last October's GKMR - Whenever I revved the engine past 4000rpm the engine went into kanagroo mode with an apparent fuel delivery method of deliver - fail - deliver - fail - deliver - fail at the rate of 2 of these cycles per second..ish. The engine never felt like stalling or cutting out but it failed to pick up any more speed restricting itself to the above mentioned engine speed limit.

This was most evident in 3/4/5th gears and it seemed almost possible to fool the engine in 2nd gear with the foot planted out of a roundabout for example in being able to rev 5/6000rpm, reverting to it's kangaroo impression in the higher gears.

Very occasionally the car would perform as expected in the higher gears but maybe once out of 10 occasions.

There is never any trouble in town driving, pulling away, stop start, cold starting - Auto choke performs fine. Only at higher road speeds and gears.

Yesterday I took the car on a 200km round trip to Killarney and the problem re-asserted itself but got progressively worse on the way home, almost to the extent that I was paying a lot of attention to my progress so as to be able to pinpoint my location for a possible breakdown truck!!

For the first time the kangaroo charateristic appeared on light throttle openings and especially when the road rose in front of me, disappearing as the the road went downhill. Changing gears up and down between 3/4/5 temporarily? improved matters as did a subtle easing of the throttle just as I sensed the problem about to appear. Worse now is the fact that it can appear as low as 3000 or 2500 rpm so it would appear to be something that is deteriorating.

For information :


There is an electric fuel pump fitted.
I use an additive when filling the tank and I know I'm not on the same tank of fuel since October.
There is also an inline fuel filter fitted.


I'd welcome people's views (along with suggested course of action) on whether this appears to be fuel, fuel delivery, electrical, air (road speed related..?) ...or something else entirely.? ???

When last did you change the plug leads and the coil lead+ the spark plugs?.It could be a plug lead.Take of one lead at a time and see is there any green corrision.Do this first,and see what the outcome is.Eugene

Electrical.
Sounds like a shorty somewhere!
I would look at the distribuitor.
Distributor cap, small crack invisible to the eye, best way to check is to find another cap.
Condenser breaking down under load and intermitently?
If i have electrical problems i drive some where pitch black, lights out, lift the bonnet let your eyes adjust for a few minutes then keeping your hands out! have a good ,look around under the bonnet.
Steve
Let me know how you get on.

I would also guess electrical and I'd suspect the magnetic pickup in the distributor (no points and no condenser on a Sport Steve). The faster you go the more the centrifugal advance increases by the action of the bob weights and springs. That moves the pickup disk and stretches the wires of the pickup. These wires break or the insulation cracks (insulation hardens with time and heat) so you get an open circuit or a short circuit causing no spark so power off. Then advance mechanism retards making electrical contact again and power is back on. So if you've never changed the magnetic pickup then I'd say change that first.

But it could also be fuel related, (delivery or carburettor) or the electronic ignition unit or anything else. If I was a betting man I'd bet on the magnetic pickup so change that first. I have a spare one somewhere if you can't get one but I've also repaired a few of these by replacing the wires (so don't throw the old one away but let me have it and I'll replace the wire so you can have a spare).

Guys - Thanks for the advice - Three opinions that it is electrical sounds like a good place to start. Hope the symptoms were explained adequately - It really is quite a quick on/off action - I'd liken the jumpy action of the car to the speed of a fornicating bunny's hind legs...ok...maybe not quite that fast!? :)

Theo - Is there a generic name for this part (ie magnetic pickup)? Would it be available in a motor factors or on Ebay, or is it a Fiat only supplied part..?

And is it unique to 131s with electronic ignition..?

Thanks? :)

Kevin!

( I will start like a machanic   ::) It could many things  ???. 

But before you do anything make sure you have paid all the speed camera tickets. Maybe they have come with a new enforcement method ;D ? 

It certainly does not look mechanical , but I would not rule it our yet.

You say:  ?fuel delivery method of deliver - fail - deliver - fail - deliver - fail at the rate of 2 of these cycles per second..ish.?

I assume your Rev counter works finer all the time while the kangaroo effect takes place ?)

Of the top of my head I would say: fuel pump intermitting  due to failure of fuel filter fouled but I would go through a whole of checks to make sure all is OK. This is not lost time as it to check all these elements before  new season and you will always find something to fix. I is better done in a garage, than on the road.   
 
Kangaroo effect sudden momentary loss of engine operation is most likely due to one of two reasons :

a/ electrical problem ( interruption of all (?) plugs firing)
b/ fuel problem (interruption of fuel delivery by fuel pump)

I would start with basics:

- check the battery connection and ground connection !!!

Test the engine idling:

-    run up the RPM and look for misfiring effect
-    uneven work ?
-    plugs firing OK ? (see how they look and change them anyway! )
-    coil delivering current ?
-    plug cables and connections to coil OK ? 
-    rotor OK ?
- points OK (are you running electronic or point ignition) ?
- all electrical connections to the distributor and under the distributor cap ( in non electronic.
- change the condenser (in non electronic) 

I expect all to be fine, but must be done to make sure we are not missing something.

Next :

Fuel:
 
- change the fuel filter ! ( or just take it off).
- check electrical connections to the fuel pump
-    check if the pump is working correctly (do you also have the mechanical pump, or just the electric). Electric pump failures are quite common and totally unpredictable. ( Listen for any unusual noise with engine on ignition but not running. Bad pump may give a strange whistling sound). I would suggest that you actually install two and have them switchable.   

 
If all this does not work disconnect any alarm system you might have on your car and throw it away ! I have found them to fail after 5-10 years of operation and give totally unpredictable efferct ( from can?t start to fail obove certain RPM , engine go dead suddenly and can/cannot be restarted until the engine is cold, etc.

Let us know what it was as it can (will?  :'() happen to all of us one day.   

Kev,

This is what you need (a spare one will be good to have in your garage)

http://shop.ebay.pl/?_from=R40&_trksid=m38&_nkw=Fiat+131+electronic&_sacat=See-All-Categories

This is the same for 124 spider 2.0 liter efi as 131 two liter.

They are quite common and yu can get them froim plases like "spiderpoint" or  "wum-autoteile"

Miro 

Hi Miro - You might be right about the speeding control!! ;D

I can see what the part looks like now - Appears a bit pricey for the size of it. It is available on the 124 site as well but they do like to charge a lot for postage (?24 to UK - maybe more to Ireland!)? :o? I might try a UK based source first and come back to Germany if no good.

Many thanks for the advice and I certainly will let you all know how it goes.

I miss the smooth torquey power delivery!!? ;)

Cheers

KEV , CONTACT THESE GUYS AND NEGOTIATE ...

http://www.spider-point.com/framework.php/mode/contact

I know I did ans got the shipping to real accetable lever.

M

Looks like the correct part but a few look the same and have slight differences. The ones for the 132 have a longer wire but can still be used on the 131. The one for the Strada 105 looks similar but it's a mirror-image. The price is a bit high for one of those; should be much nearer to ?20.

When/if you get one don't use metal feeler gauges to set the gap. You must use non-magnetic feeler gauges to set the gap and if you don't have any just the set the gap to about 1mm by eye. There should also be a magnetic shield washer/spacer and this must be installed the correct way round. A line on the base washer will show you which way up it should go. Of course there should be instructions with any new pickup to tell you all this.

Miro said something very correct above. If the pickup or any other part of the electronic ignition is your problem, then your rev counter will flicker during loss of power.

Hi Kev,

I'd have to generally agree (how could I not after such input from the forum's finest ;D ;) ;D 8)) with everything so far mentioned above about the electronics breaking down.

The pick-up is usually the first thing that 'goes'. It happened to my Racing not so long ago, although in that particular instance it was the lead from the dizzy to the inner wing mounted module (at the dizzy end) that 'broke down'. Theo generously tried to repair it - several times - but it was far easier and a better job, to replace it.

I purchased mine (pick-up 'module' complete with associated leads) from Ricambio in Banstead, Surrey, for about ?20 all in I believe, about 18 months ago.

As well as this however I'd also check out the carb and fuel delivery system as there could just be a 'restriction' in the flow, or dirt in the jets. My Abarth ran like a pig when I first owner it and despite all the electrical replacements and servicing I could manage, only the renewal of the jets made it really run sweetly. I'm not suggesting that you need to do this just yet but it wouldn't hurt to change the fuel filter and clean the small plastic mesh filter in the top of the carb.

Hope you get it sorted quickly and cheaply Kev. ;)

Let us know how it goes.

Cheers, Si 8)

Well without upsetting the German members or Italian members again get the bosch system as the marelli only ever made money for us poor mechanics  :D :D

I really should keep my mouth shut , after top Fiart eperts have spoken , but
I never could   ;)
 
Bosch or Magneti Marelli ?  Well, yes , but ... if both are in good running condition , neither will cause the kanguroo effect and there is no difference in performance (maybe in longevity).

I really would like to know what was the reason for this kanguroo symptoms.  ???

I really would expect something to do with fuel pump and/or fuel filter causign the obstrction.

If it were to do with pick up coil and ignition generally the Rev counter would likely show it.

Secondly my experience with pumps and filters point to these elelents being at fault. If the car goes inot to high rpm (in neutral gear) showing no adverse symptoms I would not see it as the cause of kanguroo effect.  Look  into the fuel supply as the reason. carbs are very much part of it , but I would look into the carbs after chackinf filter and pump.

When ( if ever have you cleaned your fuel tank?) Do you have a tendency to drive on fumes ?
This may carse the filter , pupm and carbs to fet fouled with debis from the botttom of the tank.

Get a tankfull of new gas (pertol) and try running it in on the road again... ( not too far from the garage,  though ...   ::)

 
I will be really interesting to know whose diagnosis was most accurate and why?     :o 

Miro I think you are spot on with that as I was saying about the bosch and marelli system as regards the 3ma run as I think people want to minimise any problems but you are right both systems are as good in their performance but as you say the longevity is the issue  ::)

Kev, ,

Any resolution to the problem?

Miro

Hewllo this might not be the cure but on one of my 131s it was suffering with fuel starvation and the fuel pipes got trapped by the side of the seat and as you drove it the pipe closed more through suction and it would eventualy cut out

I've left this lie for some time but should try to get it sorted now. I've been in touch with Ricambio for the Distributor pick up who quoted ?40 but advised that there were two types available, distinguished by length.

Looking at my set up I'm not sure if the location of the coil has been moved. I've attached some pictures and maybe somebody can tell me if this looks standard or not. The cable from the distributor is 5mm think and roughly 64cms long.

(http://i98.photobucket.com/albums/l250/kev131/001-2.jpg)

(http://i98.photobucket.com/albums/l250/kev131/002-2.jpg)

Thanks

That doesn't look like a 131 ignition system to me; certainly not like any I've had in my cars. I know there's two different types of ignition (Magnetti Marelli and Bosch) and maybe I've only had the one but all the Sports I've seen have a distributor cup which is screwed on and not clipped on.

Is that an electric fuel pump next to your coil Kev? That's the wrong place for it I think. Electric fuel pumps should be located near the fuel tank as they are designed to push fuel and are not very good for pulling unless they are primed first.

Hi Theo - Thats interesting but not surprising - There are quite a few mods to my car as you know - Most of them improvements in the mind of the original fitter I feel. There is some paperwork that came with the car that describes in handwriting some of the modifications - All in German though! ???

Would be interesting to get some other views particularly from some owners with standard Sports. I'll have a look at some of my archive photos as well to see if anything different stands out.

Yes that is my electric fuel pump - Unless that is the cause of my current running problems, it has given no trouble since buying the car. It does emit a hum when the ignition is switched on and before the engine is fired - Maybe this is the priming that you speak of? By the way I know that you replaced yours recently - You might let me have the supplier details as I would like to purchase a spare for the future.

Thanks

It is one of the two standard set up's. Marelli if memory serves me correctly. On my super the black box was on the inner wing near the coil. Perhaps it was moved to facilitate the fitting of the electric fuel pump.

I am sure Kevin's distributor is one of the ones available for 131s and if so it must be the Bosch system as I have the Magneti Marelli and it looks quite different (see photos below).

I've never seen a UK 131 Sport with the Bosch system and I don't know if they were available in the UK. If they were not, then the ignition pickups that Ricambio have will be for the Magreti Marelli units and I suspect they'd be different to the Bosch ones.

Kevin, if your problem is with the electronic ignition pickup, then your rev counter will also fluctuate when things go wrong. You haven't said if that's the case and if it's not, then suspect a fuel problem rather than ignition problem.

A small thing I noticed is that your main HT lead from the coil to the distributor is missing its "boot" at the distributor end. Make sure you haven't got a bad contact at that point due to dirt or (worse) moisture getting in there.

My fuel pump is a Facet and they are available from most performance car shops.? I bought mine off eBay.

(http://www.131mirafiori.com/images/fuel_pump/3.JPG)

Search for "Facet fuel pump" on ebay and you'll find plenty. They come in different capacities (called "silver top", "red top" etc). They look the same but the flow capacities are different. A Silver Top should do fine for our cars but I went for a Red Top giving higher flow and higher pressure so I then had to fit a pressure regulator before the carbs.

Your pump is quite different and looks more like a Bosch pump. Your car worked fine for years so I won't say much against the place it's located but it should really be in the boot as it would work much better there and also be safer; the idea of high pressure fuel right next to high tension voltage scares me!? :o

I think you should consider changing back to a mechanical fuel pump. They are readily available and cheap and certainly up to the job of supplying a twin cam with sufficient fuel; especially as you still have the single carb fitted to your engine. It'll be a 10 minute job to change to a mechanical fuel pump and the cheapest way of verifying if your running problem is due to the fuel pump. And you'll have a much safer car to drive too!? :D?

Hi Theo - No the rev counter stays steady when experiencing this problem - If anything the needle falls because of the "problem".

Quite happy to revert to mechanical fuel pump - I have a new one so it might be that I try that first. The car has a few jobs needing doing so maybe I will hasten the work.? ;)

Theo i recently broke up a Uk 131 sport for spares & it had the bosch ignition system in it with the clips as opposed to screw on cap & have 2 other sports here Irish cars that have the same bosch system.

As I've said before, just goes to show you how ignorant I am ....  :-[ ;D

My 131 2 litre now has the same ignition set up as yours Theo. Previously it had the same as Kev's, but the black box packed up and at the time I did not have a spare, so I swapped the coil pack and distributor for another I had. I guess I got mixed up and yours is the Marelli type and Kev's is the Bosch type......

Update: Car is now fixed and pulling strongly and on a recent test drive easily saw 160km/h without a hint of hesitation.? ;D

So what was wrong....?

It appears to have been a fuel delivery problem as many have thought. The main culpit seems to have been two very dirty fuel filters and a dirty carburetor. I say "appears" because at the same time as this fault was being fixed, must of the non standard modifications have been removed from the engine bay area including the electric fuel pump - Also at the same time the car has been fully serviced with new plugs, oil, oil filter and a new cam belt (I couldn't be sure that it had been replaced just before I bought it).

(http://i98.photobucket.com/albums/l250/kev131/SportEngine007.jpg)

(http://i98.photobucket.com/albums/l250/kev131/SportEngine008.jpg)

(http://i98.photobucket.com/albums/l250/kev131/SportEngine009.jpg)

So thanks very much to all to took the time to consider the symptoms and offer their opinions. Something I'm grateful to the forum for...as well as my very capable mechanical friend.? ;)

Glad to hear the problem is sorted Kev.Two of those filters look very bad.Did you clean the petrol tank?.If no,then i would ,as seeing the state of those two filters.If there is dirt in the tank the problem will return in the very near future.
Also one should note, to keep the petrol tank full asdoing this keeps condensation from building up inside the tank.Eugene

Worth checking the tank, although it is interesting that the 131 tanks that came from cars I have stripped all seemed to be very clean inside.

Australian members of the Mercedes Forum I frequent swear by ATF. They add a little to the tank at each fill. Keeps away condensation and cleans and lubricates the fuel system apparently.

Are Mercs 2 stroke now ::) but I think this is more because of their mechanical injection system rotting from sitting up for an age....