Running problems...

[sporty darren]

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

[kev131]

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.





Thanks

[Thotos]

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.

[kev131]

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

[mirafioriman]

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.

[Thotos]

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.

[Thotos]

Yes that is my electric fuel pump .....? 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.

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



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!?

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!? ?

[kev131]

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.

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.?

[sid131]

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.

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.

[Thotos]

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 .... 

[mirafioriman]

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......

[kev131]

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

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).







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.?

[eugene]

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

[mirafioriman]

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.

[eugene]

Update: Car is now fixed and pulling strongly and on a recent test drive easily saw 160km/h without a hint of hesitation.?
Kev,do you know that the speed limit is 120kmh on the moterways in Eire .Points on your licence and a nasty fine is not nice .Eugene
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).







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.?