Difficult starting...

[e692wtt]

My Monty has a strange problem... when he has been standing for several hours the engine takes a lot of cranking to get going, and from a cold start the engine is very 'flat' and unresponsive for several seconds, as though the fuel is not getting through. When still warm the problem is there momentarily, and then the car will try to stall at the first halt (eg the end of the road) as per fuel vaporisation - he was fine during the really hot weather in August. This has only started over the past 2 weeks. Once driving he runs fine, although he seems to be using slightly more fuel than before (29mpg versus 31, the former including fast runs)

He has a 1.6 S-series engine with engine-mounted fuel pump, and I reckon it's either the fuel pump or carb float valve.
Both of which I will look at on saturday.

Anybody got any ideas? All contributions gratefully accepted as it's driving me mad!

Cheers!:)

[GK AutoWorks]

I had the same problem on a 1.6 Auto, and replaced the carb with a brand new item. Problem was still there. The fuel pump had been replaced recently but it was the only thing i didnt replace.

[Firefly]

this doesn't sound like its the same thing, but our auto estate has had a problem for the last week or so.
when you use kickdown, it slows and then 'jumps' into kickdown and its sluggish. also, when we stop at traffic lights or other crossings, if we put it into park or neutral, it stalls instead of idling. as you all know,we had trouble with it after we got it,and an AA bloke tested the injectors, and the knackered ones were replaced. i have an idea that the replacement ones are now knackered themselves
and maybe we should think about new ones this time,as opposed to nicking them off another car.
question is, what knackers them? is it just wear and tear, or could there be a problem with the engine? also,should the replacement ones have worn out this quickly?

[E_T_V]

Well in my opinion there are 3 main ways in injector can usually fail:

1. It can leak, easily tested, more than a couple of drips per 30 seconds is knackered
2. It can be blocked, and so not letting any/enough fuel through. They can usually be cleaned, and rust in the tank is the most common reason for them to fail. (this may be your problem if the injectors are at fault again)
3. They can just wear out so not giving the correct spray pattern. Happens much more quickly with diesels than petrols becuase of the lower pressures used. This will happen so gradually you'll not notice it.

[e692wtt]

You'll only notice that the Fuel Injectors have worn out when you fit new ones. Suggested service life 50,000 miles?

Took the fuel pump apart on Monty at the weekend, paying attention to the two non-return valves I found (pressed into the pump body). The car now starts reliably after 18 to 20 engine revolutions (normally 12) and then is 'flat' for a few seconds (last week it was taking 40 revolutions then 'flat' for several seconds). I'm tempted to say it's a problem with the fuel as it's got much worse since the last fill-up (Shell Optimax). Anyone care to comment when 'winter grade' (lower boiling point) fuel is introduced? If memory serves it's September 1st then replaced with 'summer grade' on May 15th, so mebbe it's fuel vaporisation within the pump (which wasn't a problem over summer)...:banghead:

[Simon]

Fuel pumps can be funny things. I had some trouble with the diaphragm on mine and this caused two things: petrol mixing with oil, filling the crankcase with potentially explosive mixture, causing foul smells and washing the oil off the bores leading to rapid wear, and also oil mixing with fuel, rapidly gunge-ing up the plugs causing poor starting, hesitancy and flat spots and cutting out. At under £30 it is worth "repairing with a new one"

[e692wtt]

Fuel pumps, funny... peculiar. Monty normally has problems with fuel vaporisation after the engine has been stopped then restarted after between 5 and 25 minutes on a hot day when his fuel pumps (plural - got through several over the last seven years) have been on their way out, but secondhand ones from the Scrappers for a five-spot have always worked in the past. This scenario is subtley different though... which has thrown me a bit.

Will try to get a new one tomorrow (don't expect much difficulty) but expect to pay nearer £20 than £30 from other cars I've bought fuel pumps for. I shall keep you informed.

I always strip and rebuild the carb every couple of years so will do this this weekend as it is due anyway. Cleaning the dashpot and innards usually makes the car run smoother anyway I've found. Bit of 70-grade sandpaper for a shine... only kidding! Solvent and kitchen paper does the trick for my Monty's Carb, if anyone else wants to try it.:laugh: Anything more abrasive messes up the fine clearances on which the carb relies and makes it fit only for scrap.

When fuel pumps' diaphragms split, they normally deposit a lot of petrol in the crankcase fairly quickly, I understand, and the quickly-rising oil level is easily spotted (as is the petrol smell) so I think you were unlucky there, Simon! One to watch on regular oil checks for those of us whose cars don't have electric petrol pumps...

[e692wtt]

Fuel Pump £17.75 "be here this afternoon ring before you set off to make sure". Not bad, eh?

Let's see if it solves the problem...

[MaestroMatt]

Where can you get a new fuel pump at that price? I think I need one. I have an R series engine - do PartCo do them or do I need to go to Rover?

[e692wtt]

Matt,

You'll hate me for this but I paid just £12.63 at a place called "Alan Quine's" in Whitefield just south of Bury. Ring them on 0161 796 5797 and ask about Packing and Postage Rates. Or I could send it along with the other stuff you want off the VDP which is lying under a bed still following my recent move. It's made by a firm called 'Moprod' in the Midlands and looks identical to the existing Pump. Am off out to fit it now the engine has cooled off a bit.

RDGelder gets his service parts from Quine's as well, but I guess PartCo etc would have the same opump even cheaper. Mebbe try ringing round and see if they can beat Quine's + P&P?:)

[PSIKO]

Originally posted by e692wtt
when he has been standing for several hours the engine takes a lot of cranking to get going, and from a cold start the engine is very 'flat' and unresponsive for several seconds, as though the fuel is not getting through. When still warm the problem is there momentarily, and then the car will try to stall at the first halt (eg the end of the road) as per fuel vaporisation - he was fine during the really hot weather in August.

Do 1.6L still have the anti perc fans? The fan which stays on for approx 10minutes after you switch the engine off, as to cool the manifold? If they do then check that this is still working properly

Also, on your main engine loom, check to see if the connections aren't filled with grease and general 'gunk', as this may also be affecting your starts

Other problems could be yep the carby valve sticking, or the fuel pump or injectors; check the Haynes manual (I don't have one :() to see if it has a cold start valve, which adjusts the valving, and then closes when it's warm (if you do blow down it when it's cold to see if you can)

Cheers

[Wonko_The_Sane]

The 1.6 as a rule I'm sure doesn't have the carb fan. Not the SU 1.6 anyway.

Agreed on the engine loom..must look at mine.

Mine is starting like a sack of nails...30-40 seconds on the starter, and no go in drive for 5-10 seconds from standstill..doubtful the fuel pump is an issue there..more likely it's the 18+ month old splitfire plugs at the end of life. It's also having an issue with running on, all in the last 2-3 weeks.

Mine did the "fuel starvation impression/stalling at idle" thing about 18 months ago...in the heat. I removed the connection to the manifold heater to reduce that electrical load (and boy does that affect the idle sometimes..), and stripped/cleaned the carb..and it went away.

I then followed that with a cold air only intake mod, and it settled quite happily. My fuel cutoff valve is also out of this equation..it's rigged to a manual switch .

[e692wtt]

Hmmm...

I've got splitfire plugs in as well, mebbe 12 months/8000 miles old. The engine takes 16 turns of the crank (ie 16 'whurrs') now, then fires but seems 'flat' and is very 'rich' when it finally revs after mebbe 10 seconds. It's fine then for the rest of the day. It seems to be getting better as the colder nights come, as if the engine cools quicker and less fuel vaporisation occurs?

Monty has a bad 'carb icing' problem in the winter (seems to be the local weather) so I'm keen to minimise this by using the standard filter setup. interesting comments re the cut off switch, I'm tempted to say this is sticking as well. We shall see.

Must strip the carb this weekend...

Cheers for these comments, Wonko_The_Sane!:)

[G Force]

Hello there, as well as the things already mentioned I would check to make sure that the carburettor vacuum switch diaphragm has not gone. To check this just remove it and suck on the vacuum connection if you can suck through it then it needs replacing.

If the carburettor is icing in winter, check that the control flap below the air filter is not seized in the cold air position, and that the flap moves if you suck on the pipe that connects it to the thermac switch in the plenum chamber. Then if all the pipes are good and the manifold tapping is clear, then change the thermac switch.

Cheers Gary

[G Force]

[QUOTE]Originally posted by Wonko_The_Sane

I then followed that with a cold air only intake mod, and it settled quite happily. My fuel cutoff valve is also out of this equation..it's rigged to a manual switch .

Hi. Just a thought for yours, if you use a manual switch to control the fuel cut off valve, the valve could still stick open. I personally think it is not worth leaving the valve connected because they are so prone to sticking. The best way I feel is to make sure the valve is fully closed then leave it disconnected.

[e692wtt]

Cheers for the comment re the 'vacuum switch', but when mine went it just used more fuel (25mpg) and stalled after a moment's idling (every time). It gets tested every week when I'm under the bonnet and is ok (or was last weekend).

Agreed re the 'overrun fuel cut off' thingie, I'm tempted to say it's sticking, but this wil get sorted when I strip the carb. Probably will try leaving it disconnected, as you suggest, as well.

The 'warm air to carb' system gets checked for 'flap operation' every couple of months, and I have changed the 'thermac' unit and the 'hot air hose from exhaust manifold' as well - the thing seems fine, just on damp mornings below 5 deg C the carb ices for the first few minutes, regardless of this attention...


Another question... how easy is it to undo the float valve seat in the carb body. I think it's meant to unscrew so it can be replaced (along with the 'needle' as a set), but was mighty tight (technical term...) last time I tried so it got left. Could I trash the carb trying to unscrew it?

Cheers folks...

[G Force]

Another question... how easy is it to undo the float valve seat in the carb body. I think it's meant to unscrew so it can be replaced (along with the 'needle' as a set), but was mighty tight (technical term...) last time I tried so it got left. Could I trash the carb trying to unscrew it?

Eor best result you need a good quality slim 3/8 drive single hexagon socket because the valve has a taper seat and are (ft).

cheers

[e692wtt]

That's reassuring to read... Thought I might do some harm this way, but apparently not. Is '(ft)' a 'technical term'?:laugh:

Thanks for the info, Gary.

[Wonko_The_Sane]

G-Force-

I kept the cutoff solenoid as a secondary engine shutoff mechanism to try and avoid the runon..:) Flick the switch as I pull up the drive, then shut the engine off as it dies through lack of fuel. Good immobiliser too..;)

I Actually removed mine from the carb totally and spent an hour with a dremel and glass paper cleaning it up and making sure it worked smoothly with a 12v bench pack..:) It's unlikely to stick now..;)

I'm sure mine is just complaining about the plugs..I'll find out this weekend..:) Total removal of the ignition parts, a good clean, and a blast with "damp start" beckons..:laugh: :party:

[SimonR]

Rich,

if you're thinking about stripping your current carb, you might want to do as I have just done for my Maestro. I found a late 1.6 unleaded Monty with low mileage and took the carb. I've now rebuilt it, ready for fitting to my car when I do the engine. This has three advantages:

1) You can take your time rebuilding the carb while you drive using your other one
2) The later carbs don't have cut-off valves and some think they run better
3) You'll have a spare carb if you knack either one in an attempt to clean it.

Mine cost me about £20 from the scrapper and I think it's well worth it. A can of SU Carb cleaner was also an essential item and will cleant just about anything, excluding plastics, which it melts! Two other things to replace when you change the carb are the 'o' rings on the stepper motor. You simply would not believe the difference this made when I changed mine.

PS I'd lke to point out that the Monty was in the scrapper when I took the carb :D

[G Force]

[QUOTE]Originally posted by Wonko_The_Sane
[B]G-Force-

I kept the cutoff solenoid as a secondary engine shutoff mechanism to try and avoid the runon..:) Flick the switch as I pull up the drive, then shut the engine off as it dies through lack of fuel. Good immobiliser too..;)

Hello there, nice idea you are obviously a good innovator. It reminds me of what Leyland Daf did when they started fitting the 2 litre O2 engine to the Sherpa van. They used a manual choke SU HIF44 but left the orfco valve fitted as an anti-runon valve. In order to make it work properly they fed it via a 10 second timer relay, which when the ignition was turned off the valve was switched on for 10 seconds. But you guessed it they were dogged with complaints of difficult starting, flat spots and poor performance usually after a restart.

Regards Gary

[e692wtt]

Took Monty's carb apart at the weekend, and he now seems to be cured... the rubber overflow pipe was split the full length of the stub on the carb body, and both rubber pipes to the ORFCO valve were split the full length of the ORFCO valve stubs... (so comments about checking the ORFCO valve weren't a million miles out - more like 1/8"!), and the 'plastic mating piece' where the main crankcase ventilation hose joins the carb body was burned and split. The carb was literally awash with petrol, much more than expected, and I managed to remove a satisfying amount of 'resinous gum' from around the float valve needle and seat.

I fixed the various hoses with Duck Tape (what else? useful stuff!) and luckily I have a 'spare' carb off a Rover 216 for other odds'n'sods (though of course the 2 ORFCO valve hoses are much shorter on the spare...).

Started 'on the button' today, revved cleanly from the start. Now I just need to adjust the choke cable...
:)

[G Force]

Hi again, great news that your motor is running smoother again. The small valve with 2 pipes connecting it to the carburetor is the vacuum switch, and the valve with the wires going to it is the (ORFCO) over run fuel cut off. Easy to confuse. if the pipe nearest the centre of the vacuum switch was split this would have the effect of weakening the mixture when on choke causing most of your symptoms.

Cheers Gary

[e692wtt]

You're quite right, it's the vacuum switch hoses I've bodged. I'm losing the plot, I think... (it had been a long, not very easy morning). I don't usually talk *that* much garbage...;)

Have had to reset the carb as it was too lean (3/4 of a turn on the mixture screw, set 'by ear') and it feels like a different car. Just need to get some new hose (got some spare in the boot, will try it tomorrow). Goodness knows how long the hoses had been deteriorating! One to check at a service, methinks.

The excessive smoking has stopped as well, which is interesting... but not unexpected if it was running too rich.

Cheers again for the input, chaps.:)