Fuel Starvation ???

[HFStuart]

I've got a problem with my Lancia Beta Spider 2000. The symptoms are similar to fuel starvation but I'm not convinced.

The car runs on Bosch electronic ignition. It has a new fuel tank, cleaned out carb new fuel filter(s) and a low pressure electric fuel pump. I tested the pump today and it's producing about 18 Gal / Hr at the carb fuel inlet - so if it is fuel starvation it's not down to the pump or lines. Additionally the in line filter between the pump and carb always has fuel in it.

When the car is hot the engine stalls and cuts out if you run it under anything other than very light load. This happens at low engine speeds as well as high so it cuts out at 50+ in top or when climbing hills at lower speed in lower gear. It stutters first and then cuts out completely, there's no response at all. The rev counter stays on suggesting that the LT side of the coil is fine. After coasting for a few seconds (or backing right off if the car hasn't stalled completely) it always restarts.

When the engine is cold it runs perfectly. I can run on high load for as long as I want and there are no problems - this I mainly why I don't think it's fuel problems I can't see how that would only happen on a hot engine.

Any ideas, suggestions or anyone had this themselves and found the cause ?

Stuart

[Gregory Smith]

I think it is a fuel problem! If the car is cold, the choke is on and you have enough fuel to boogie around. Warm engine, choke off and suddenly not enough fuel.

Main suspects are jets, including idle jet, and carb inlet filter.

[HFStuart]

Thanks for the suggestion.

Pulling the choke out while it was playing up made no difference, also if this was a blocked jet I'd expect it to at least try to run ie a blocked idle jet and it would run on the main, blocked main and it should idle and /or run (badly) on the secondary choke when opened but when it goes it's totaly dead.

The needle valve is fine (brand new in fact) and I checked the float level while cleaning the carb. There were no blocked jets, not even any sediment in the flaot chamber. Nothing I did to the carb over the weekend made the slightest difference to the problem.

Tonight I replaced the dizzy cap, rotor arm and HT / Coil leads. None of them were the problem but the clean ones do look nicer ! I tried with the petrol cap off too and it's not vapour lock or tank vacuum.

The coil is next as they're cheap.I might see if I can get a 2nd hand control unit too just to check that out.


Any other ideas ?

[1,6 HF]

Because this is happening at all engine speeds (i.e., on both the idle circuit and the main circuit), and because it only happens when it's hot (and you've ruled out vapor lock), I think you're right that it's not a fuel problem.

I'd suspect that either the coil or the electronic ignition box are cutting out at high temps.

[chrisc]

Not sure if the 2000 has it but my VX also includes an ignition amplifier mounted on the inner wing behind a heat sink that could be suspect.

[Will]

I see your avatar is a head out from the engine, presuming you've hopped up the output then your problem may be the heat range of the plugs if you are still running stock plugs. Try changing to a colder plug. (if this is a newly worked motor, if it's been running fine this way for 20K miles then we can assume you are OK on this front)

You didn't mention what the existing plugs looked like. Fuel starvation should give you the same whitish enleanment burning that would also be characteristic of a too-high plug heat range.

The tach doesn't indicate that you are getting adequate spark, only that you are getting enough to drive the tach. A short or arc between the HT leads and anything at ground potential can cause lower circuit resistance and thus more current through the module, which in turn can cook the module. The reason I mention this is that if you replace the module and the new one mysteriously fails, you almost certainly have a HT leak, one problem causes the other.

Good Luck! (should add that directly to my sig!)
-Will

[HFStuart]

Will,

Thanks for that. The engine is standard (I painted the cam covers while I was waiting for parts, the Lancia script is in gold. Pointless but I think it looks good) the plugs are new NGKs and look fine if a bit sooty as a result of recent very short journeys trying to find this fault.

I can't remember if the tach output is the same pin or a different one to the coil LT output but anyway I agree the ignition module has to be suspect. A new coil will be with me on Friday, if that doesn't work it'll be a new module. The good news is that they're both still available from Bosch and both are cheap.

New bits as above should mean there aren't any shorts on the HT circuit

Fingers crossed as I'd really like to make it to the Beta 35 thing at Stanford Hall on the 19th.

Stuart


PS In case anyone else ever needs to know the coil is Bosch p/n 0 221 119 030, and the module 0 227 100 014

[Tonyj]

Could I suggest that you look on the Betaboyz forum website as Mikeymike may be having a similar problem. I still have problems despite my temporary fix. In the past the car would run sweet and I could almost predict when the problem would occur as I drove home - it occured at roughly the same distance! Then it got very bad and car wouldn't go any distance before stopping. Thought it was blocked outlet gauze so have put in outlet via sender as a temp fix but recently she shudders at odd times so maybe it's an electrical problem as well - such as the distributer pick up ot the heat sink that Chrisc has mentioned! ;D it's all good fun and keeps me out of mischief.

[andybeta]

you might check the LT ignition pick up lead inside the distributor. The wire becomes brittle over the years and it can crack meaning poor connection result misfire and cutting out. This is what happened on my VX.

If the distributor seals aren't sealing fully oil will be deposited on it causing insulation to deteriorate. Where is the distributor on your spider? At the front by the alternator or on the end of the cam? If it's on the end of the exhaust cam near to the exhaust then heat will also play a significant part in it's break down. Anyway this wire might be failing making intermittent contact resulting in misfire when warm, cutting out at higher road speeds and lower engine revs such as under load in top so you change down to keep the revs high which exacerbates the problem. Solution - get a new distributor pick up from Chris Bastow and a new distributor O-ring oil seal if contamination has taken place. You'll also have oil on the outside the distributor and adjacent and down the back of the engine. A new O ring is only 20-30p.

Also as mentioned the coil amplifier can fail but if this was the case I suspect the car wouldn't run at all.

To check the HT side start the engine in the dark and check for any arcing. Check the HT lead from the coil to distrib is fully in place and the distrib cap itself is good plus all other HT connections.

Also another dodgy coonnection to check are the main power connector blocks under the dash above the steering column which feed the ignition switch. These can vibrate apart and/or corrode. Wiggle them and firmly push them together and hey presto the car bursts into life.


Hope some of this is of help and Good luck

[HFStuart]

Andy,

Thanks. The dizzy is block mounted but getting a new pickup from Chris sounds like a good plan. If my new coil / tested module don't help

Stuart

[Will]

Hi Andybeta;

Good call to bring up the pickup, I don't know if it's the oil to blame since it happens on plenty of cars without leaking oil bushings. I think there are two failure modes- one is caused by aftermarket non-Marelli pickups that have leads too long and have to be twisted into a "pigtail" to keep from rubbing on the dizzy internally. The other is embrittlement of the plastic insulation that (IMO) is probably caused by the dizzy caps that have no ozone vent holes. That's kind of a catch-22 in my book, do you want to let ozone out, and possibly moisture in?? I think I should patent and sell dizzy caps with an 1/8" hole in them and a 1cm patch of Tyvek glued over the hole. There has GOT to be a market for those! Of course, with the Tyvek there they won't be as good at draining the OIL out ;)

[Tonyj]

My VX has had a full reoccurance of the fuel starvation problem despite my modified fuel outlet form the tank. She's been running well for months and now it's started again! The fuel is leaving the tank, the pump works but there is little to no fuel in the pre carb filter and the pump takes an age to pump fuel into the filter.

I disconnected the fuel line pre the 'hot start regulator' and the fuel pumped out well. I've connected the fuel line straight the the pre carb filter, missed out the 'hot start regulator' and sensor, and will try this over the weekend.

Could the 'hot start regulator' be to cause of the problem? Can any one tell me how it works and what it does? ???

Missed the Auto Italiano day at Brookland because of this problem and I don't wont to miss the meet at Stanford Hall! :'(

[Petercoupe]

Hi

I had same problem when I changed my fuel pump, I also changed fuel hoses all around. For 2-3 months had fuel starvation on uphill mainly.

My problem was that I made a kink in one new fuel hose I replaced and fuel was not going in carbie at satisfactory rate.

After shortening hose and eliminating kink car runs nice.

Regards
Peter

[HFStuart]

Peter,

I haven't been able to look at it for a few days but when I can (Thursday) my plan is to look at the flexible hoses to see if any of them are kinking or collapsing when they get warm through radiant heat from the exhaust.

It's a long shot but you never know and your post has given me some encouragement.

Thanks,

Stuart

[HFStuart]

I finally managed to nail this today - or at least the cause. It died while idling and I whipped off the top of the carb to find empty float chambers (so points to those that said fuel starvation!)

The thing is I'd spent the morning replacing the fuel lines, filter etc etc. As a last resort I disconnected and plugged the fuel return. Bingo problem solved. What I suspect was happening was that the 6mm return line in combination with my low pressure 1.4psi pump was resulting in too little pressure at the needle to fill the carb - so the pump was happily circulating the fuel with relatively little actually going in. God knows why it only happened while hot though.

Anyway do you think the 34 DMTR will be OK with 1.4psi feed and no return ?

Stuart

[Will]

Depends on whether the motor gets hot enough to boil off the very-slowly-moving fuel in the line, proper practice would be to fit a restrictor
(say 1mm) in the return line to limit the volume of the flow back and thus hold pressiure on the carb, and 1.4 is a bit low
IMO, I know some people like it there but I've had better luck with around twice that. Great you got it figured out though!

[KeppelmanJ]

You will know under extended hard acceleration going up hill. If it doesn't crap out it's ok.

[Tonyj]

I've been running with no return on my temporary VX low pressure (4 to 5 psi) setup and haven't had fuel vapourisation in the lines - yet! Noticed that in the return line there was a restrictor so maybe someone before me had problems getting fuel to carb using the high pressure system. I will reconnect the return when I've cleaned the carb now I know there's potential problem of heat vapourising the fuel but it ran for months without fault and some days where hot. Hopefully when I've reconditioned another tank I can go back to the origianal set up.

[rosssomerville]

Hi ,I am having the same problem with my 2000ie 1983. I have rebuilt the engine and all has been running great until last night when it got up to temp and then under heavy throttle it starts to lose power quickly and if the throttle is not released then it will stall out. It feels like the fuel pressure is dropping under acceleration and when let to idle the pressure builds up again. It could be knackered pipes it could be electrics I just dont know what might be causing this. I shall ask chris at Betacar he will likely have come accross this before.

[Modano]

Hi all :)
I'm a happy owner of a Lancia Beta Coupé Serie 2 1981 (but made in 79), french limited edition.
It is a 1300 carburetor engine. Don't know if this specific one was exported in USA.
Anyway, I would like to bounce on HFStuart sentence :

He said earlier in the thread that coils were not very expensive.
Which kind of coil can I put in my engine ?
I have a Marelli Electronic Ignition coil "2000A".
What can I use for replacing this one ? Blue coil Bosch ?...

The same model costs 300$ at one of my supplier. Way too expensive for "testing" my coil...

Thanks a lot :)

[HFStuart]

Modano,

If it's running with electronic ignition and a carb then the bosch 'red' coil should be fine. (Bosch p/n 0 221 119 030) it was less than £30 for me from a good motor factor.

I'm sure Chris at Betacar ( http://www.betacar.co.uk/ )could ship you a second hand one cheaply too.

Stuart