Technical Engine stall issue

[ex19]

Hi all,

Very new to this, but thought I would say hello to you all as a new member and see if there is anyone out there that could possible help me find the solution to my F-reg (1989 X1/9 VS), cutting out/stalling after running fine for miles in some cases.

It will always seem to start and run perfectly for a while but then stall again and again (Only when driving.. never on idle at lights etc) which is more than a little strange. The precursor to it cutting out (even if cruising at 60mph happily) is the rev couter flicking up and down and some occasional engine stutters, though sometimes it skips that stage and goes on to just stalling the engine.

The car has had new fuel pipes fitted last month, 2 inline filters and a new fuel pump in August last year, though the fuel is not seeming to get into the filters at much pressure..

I also wondered if it was an autochoke issue maybe? When started from cold it seems to rev steadily at 4000rpm and not come down on its own until the accelerator is tapped which seems odd, though could be entirely normal.. I am certainly no Fiat mechanic thats for sure! The pipes to the housing do not seem blocked as I can blow through them. I did find that cleaning the connectors to the temp sensor on this housing improved the issue a little but certainly did not cure it. I can now usually drive about 5 miles without too many issues now! Water temp on the dash is always a little below 90 and I think the fuel pressure guage is not working as it certainly has oil but the needle always sits at the bottom of the guage.
Not sure what else to tell you really,
Hmmm...

If there is anyone with even a bit of guess at what it could be and where I can start looking I would be extremely grateful.

Thanks again for your time if you got through to this stage, and hope to hear from you soon so I can actually get out and have some fun in the thing!

Regards to all X1/9 owners out there,
Nick

 

[sledgehammer]

Could be the fuel pump on the way out. Have you checked the points and plugs? Could be something as simple as the points gap too small..
Difficult to diagnose with out seeing the car.


Guy

 

[jimbro1000]

The automatic choke is only a semi-automatic. It will not close all by itself and when starting the car you have to prime it by pushing the throttle down once (at least) before turning the ignition.

To be honest it sounds like the tuning of the carb is way, way off, the running out of fuel after a while is either a) fuel pump struggling, b) float level too low, c) float needle valve sticking, d) the fuel pickup is partially blocked or e) an air leak.

The fact that the fast idle is set so high (it should only rev to 1500rpm absolute maximum) suggests an air leak and someone has tuned the car to cover it up. The best thing to do is get the ignition parts replaced (plugs, points and condenser), ignition timing checked and then get the carb serviced and reset.

What is worrying me is the rev counter bit - the rev counter is fed from the coil so if it starts flickering around as you describe then the coil is not getting the trigger signal from the distributor *or* the electrics are cutting out. If it was just fuel the rev counter would keep going even if the engine runs out of fuel as the ignition would still be triggered by the turning of the engine as you drive along irrespective of fuel starvation - just so long as the car is in gear and you haven't depressed the clutch.

The problem is you have too many unknowns - if you were 100% sure that everything was working except the idle and the cutting out then it would be fairly simple diagnostics but not with so many different factors.

The fuel filters aren't doing you too much by way of a favour either. You only need one, although they do need replacing as the fuel system is recirculating so a lot of the dirt in the fuel tank ends up in the filter so keep the second one and use it as a spare for your next service.

Your water temperature is fine but the oil pressure sounds wrong. If the orange warning light isn't flashing on though then the odds are the sender is past its prime and needs replacing. The idiot light uses a simple switch while the gauge is on a separate feed.

 

[ex19]

Hi Jimbro and Guy!

Thanks for the advice and suggestions. I have already just bought a new fuel pump and the plugs/points have recently been changed too, but I will check and change them again and add a new condenser.

For good measure I will get a new distributor and leads too and see what that does..

Is there any specific parts or brands you recommend for this car for any of this stuff?

With regards the carb, I can get that serviced locally I think, and get them to specifically look at the float level and the needle valve, but I am a little concerned with the air leaks point.. Where could this be from and what could I do to check and fix?

Again, thanks for your advice and I shall get the new ignition kit and let you know the results.

 

[sledgehammer]

Hey,

The air leak is most likely to be from the inlet manifold, this can cause really bad running issues.
I have had it happen on my X1/9, it was leaking where the manifold meets the cylinder head....It was so bad fuel was leaking out (very little).
But it could also be leaking where the carb mates to the inlet manifold.
Best way to check is see if there are any obvious fuel leaks, or spray WD40 around the carb base and if you can around the manifold to cylinder head joint...this may be difficult to get to.
Any change in revs or bubbling and you have found a leak.

Guy

 

[ex19]

Thanks for the advice, I shall have a go at this when its not dark or snowing on me!
Will let you know how I get on.
Nick

 

[ex19]

Right then,

Here is the update on things checked so far..
New plugs and leads which definitely seem to help. Dizzy cap was as new, and the rotor arm got a clean though did not really need one..both these seemed recently replaced and no signs of wear. I think the intermittent rev counter problem was a random symptom of poor leads as this has now stopped since the clean/change. I have new points/condenser though have not fitted them yet.

There are no air leaks as far as I can tell around manifold or carb by doing the check as described so thats good news.
The engine starts great from cold and holds the revs about 3500 on initial start up, going to a little less than 2000 with a tiny tap of the accelerator, (which may be sticking or incorrectly set then if it should start at 1500rpm) it then sits happily at 900 on warm idle.

Could there be an issue with the autochoke coming back on or sticking somehow after a while of driving, therefore flooding the carb?

I have removed one of the 2 inline filters as recommended, and there is a good flow of fuel coming through the new fuel pump and new fuel lines.

The car now has a slight stutter initially when accelerated while the choke is still on, but runs great (very well in fact!) when warm.. Until the engine just cuts out completely.. This is after maybe 10mins when the engine really starts to heat up.

When this happens, the engine turns over but will not start for a good 2/3mins then eventually starts ok and runs for maybe a few yards then cuts out again etc etc..

Have we narrowed this down to autochoke and carb set up do you think?

Thanks for all the support and advice, it is much appreciated from someone who does not have a clue about mechanics!

Cheers all,

 

[sledgehammer]

Hi Nick,

I would replace the points and condeser and see if it makes any difference. The points do wear, in that they can get a build up of carbon
on one side (it might appear about the size of a pin prick) of the points so you cant get the proper gap.
The points gap may be just enough to start the car but as the engine gets hot, every thing expands and the points gap reduces too much for it to continue to run.
This is pure speculation of course, it could be a dodgey fuel pump!

Guy

 

[jimbro1000]

A quick and simple question for you.

Have you watched the autochoke working from cold?

It should be something like this:

Before starting you have to operate the throttle fully to reset the choke, the choke should then be in the fully "on" position.

Start the car without touching the throttle (if you can't do this there is probably something wrong elsewhere)

Once the engine is running and the autochoke housing starts to warm up whenever you depress the throttle (or work the throttle with you hand directly on the carb) the actuator arm is released from the housing and this allows the autochoke mechanism to reset to an appropriate position for the coolant temperature.

Ultimately once the engine is warm the choke should be in the fully "off" position.

While the choke is on the idle speed is adjusted by turning the thread of the actuator (it is basically just a screw). The further it pushes the arm out the faster the cold idle is.

How long the choke stays on (sometimes referred to the idle mixture) is determined by rotating the outer choke housing. If you look closely you should see engraved marks on the inner and outer housings that indicate what position the choke is in.

So far it just sounds like all of this is pretty much correct although I am worried by how fast the engine starts - 3500rpm is enough to potentially cause damage due to low oil pressure and poor lubrication. The 2000rpm sounds more like it but even this is at the upper end of the expected cold idle range.

Getting on to the matter of the engine stalling, I assume you have a transparent fuel filter (most are). If this is the case, when the car stalls can you see any fuel in the filter or is it dry? If it is dry that points to starvation either from the pickup or the pump, if it is full of fuel then it is either ignition or the carburettor.

 

[littlephil]

just something to add, do what jimbro says then if your car cuts out, grab the coil, if its so hot you've got to take your hand off, chances are your coil's knackered. But it does sound like a fuelling problem.

Jimbro, how do you turn down the cold start rpm? mine has always started at 2800rpm

 

[jimbro1000]

just something to add, do what jimbro says then if your car cuts out, grab the coil, if its so hot you've got to take your hand off, chances are your coil's knackered. But it does sound like a fuelling problem.

Jimbro, how do you turn down the cold start rpm? mine has always started at 2800rpm

If you look at the actuator arm that comes out of the choke you will see that the end of it has a screw head. Just turn the screw to shorten the arm to reduce the cold idle speed.

 

[ex19]

Hi all,

Thanks to everyone for giving me some knowledge on what to look for here.. I will change points and condenser (If I've got the right parts) tomorrow morning if it is still dry (Thanks Guy) and have a go at adjusting cold the idle speed with Jimbro's awesome checklist of things to do (Thankyou!), and it does always starts just fine without the accelerator being needed so thats something I guess.

I will then go for a mini run and wait until it stalls again, and check the coil temperature (Very useful tip.. Thankyou Littlephil) and see if that is a suspect.

After that the car is going to the garage I think as I do not think the carb is set up correctly and that is beyond me.

Oh, by the way, the fuel filter is clear and it is always totally full of fuel when it stalls. I did already check that. If anything I am pretty sure it is flooding as the is more often that not a backfire now the 2nd fuel filter is off.

Thanks again all and I shall keep you in the loop with it just for the record..

Nick

 

[jimbro1000]

If it is "flooding" then the problem is likely the needle valve in the top of the float chamber. The float is supposed to push the valve into its seat when the fuel level is at maximum, the excess fuel is then returned to the tank via the return circuit. If the return circuit is blocked you are likely to have problems (worth checking before pulling the carb apart).

The valve itself is normally pretty foolproof but they do eventually wear out... normally the car would stink of fuel though if this were happening and it would be a real pig to start again.

It is all pretty unusual though, far more likely is that something is overheating resulting in loss of functionality (the coil is a good bet still) but without some diagnostic equipment you'd be chasing your tail for ages and spending money on "possibles" until you found the right one.

 

[littlephil]

i can't see it flooding either as you'd have smelt the fuel and... well... run off.

Its either something electrical or fuel. easiest way i found to check it sparking (as i don't have any friends) before i took mine out i removed the access panel in the spare wheel well behind the drivers seat and carry a spare (good) sparkplug. when it cuts out pull the seat forward and take off the lead for number 1 (closest to the drivers seat) pop in the new plug and rest it on the engine or the body (good negative contact) where you can see it then turn the engine over if it sparks its fuelling, if it doesn't you need a new coil.

Mine was cutting out after a right good blast, i cured it by getting it to run then slowly undoing the idle and main jets while pumping the throttle. i still have to do it every now and again.

 

[jimbro1000]

And people wonder why I gladly ditched the twin 40 setup on my racecar in favour of a fuel injected turbo system....

 

[littlephil]

sod the turbo, just injection and megasquirt is going going to make a big difference on mine ;-)

 

[ex19]

Well, I am finally back from working overseas and as its good weather so its time to get on with this car again!
To continue with whats already been changed..

The carb has been serviced and put back.. still nothing..
Its had a new coil (Just in case), new condenser and points and some new rewiring to replace old frayed stuff.. and it still doesn't work. In fact its now stopped altogether..

The latest thing that seems a culprit is the distributor itself so I need to find an S178 type Marelli (if anyone has one spare at a reasonable price so I can check). I think this may be the main issue after chatting to a friendly garage nearby recently.

If I can get a replacement distributor I will know if my friendly garage is correct.

Cheers all,

 

[Tiffx19]

Distributors very very rarely go wrong- They are just a shaft to open the points. Make sure the wire to the points isn't contacting anywhere- They can rub through just as they go into the dizzy body also if there is any contact between the two parts of the points you wont get any life- they have a fibre or plastic washer between them. . Put the ignition on and flick the points with a screwdriver to see if you get a spark.

 

[littlephil]

have you lost the spark completely? on all cylinders? I don;t think that it would be the dizzy as all it does it turn round and make the contacts on the copper posts in the cap. If the dizzy has failed then you'd have irratic firing, flats spots but it would still fire.

can you smell fuel?

 

[farynho]

engine turns off while driving
I have a same problem. When I drive the punto mk2 2002. 1.2 8v the engine turn off. I drive on 2500-3000rpm and the speed is 50km/h. The engine turns off, the control lamp is turn on. I stop the car, try to start again and its work. The diagnostics show no bugs. The mechanics didn't know what is the problem.

Please help me.