Engine stalls

[Sharpen]

Hello everybody, any theories on the following fault would be very welcome.

When the throttle is opened quickly the engine stalls as if starved of fuel. The engine can be revved all the way round the clock if the accellerator is pressed gradually.
Strangely when the engine gets upto full op temp its fine.
I'm hoping this is a known issue, I saw somthing similar on another beat.

Shane

[adrianp]

Sounds like the idle control valve is sticking...

If the throttle is opened slowly, the engine can probably compensate whilst the valve closes

But I guess if the throttle is opened fast then the valve doesn't close quick enough and the engine gets too much air for the available fuel.

I might be wrong on this and I'm sure steve will be along to tell us the answer...

Ady.

[Sharpen]

Thanks Ady, i wondered if it could be some sort of automatic choke problem but I'll check your idle valve suggestion, could you point me in the right direction as to its whereabouts?

cheers
Shane

[Sharpen]

Hello again, back again with this problem- its been too cold to do much work on my little beat so heres an update:

- car starts brilliantly from cold and revs and sounds well, fitted new iridium plugs - old plugs were black and carboned up
- replaced ecu caps, old ones looked fine anyway
- I heared that centre contact in distributor cap can stick, mine was stuck! free'd off ok
- had a look at what I think is the idle valve and I'd say its ok as disconnecting and reconnecting it slows the engine revs down to about 800revs then back to abot 1200 when reconnected

fault still exists: after about 10 minutes idling the engine starts to faulter and opening the throttle quickly then kills it (slowly doesnt seem to affect it). then it wont start again, it just coughs and splutters when its cranked over.

I'm really sorry to repost this but I'm loathed to take it to a garage and hope to fix it with the help of you guys.

[Jerry]

sharpen
Could it be the main /fuel pump relay?. I know its not the classic symtoms, that is failure to start when hot.
You could listen for the click of the relay and the buzz of the fuel pump when you have one of the problem starts. It could be. ( this is only a theory) that at idle the voltage delivered to the, possibily faulty, relay is not enough to hold it in. When you rev the alternator could kick the relay in. At starting the revs and therefore voltage would again be low.
I have just had to buy a main/fuel pump relay (part No. 39400-SS1-003, it was £41.15+vat. its easy to fit except for all the trim. It cured my problem.
My son also has a beat this stumbles from idle sometimes. We will try my new relay in his car when we have time.
I hope this is of some help.
Jerry.

[Midship]

Main relays are a pretty common problem but im not to sure if this would be the cause since they generally only screw up when warm and your problem is experienced when cold

To be totally honest this one has me slightly :confused: personally, what I would do is, take off the intake manifold strip it and fully clean it with carb cleaner or similar wont do any harm, you would be amazed at how dirty it can get. Be on the look out for anything that could be sticking etc, then after that I would try and get a working beat and start trying sensors... throttle sensor and map sensors etc

What dose your car idle at when cold and when warm?

Hope you get it sorted soon

[Jerry]

Sharpen
Last night I ran your' problem by a Cappuccino expert. He was broadly in agreement with all that Midship has said.
Substitution of parts is a good method of fault finding. I am fortunate with my son also owning a Beat, but it is the only other one I have ever seen!
My Cappuccino mate added, check battery condition. and try injector cleaner. If the injectors were gumming up this would have the greatest effect at idle. The latter point is still following Midships thinking.
Good luck
Jerry.

[Sharpen]

Thanks guys for your ideas.
I took the inlet manifold off today and noted a fair amount of oil in the bottom of the intake cowling. This worries me as I have remembered that this fault developed at about the same time as I topped up a very low oil level shortly after buying this car. Maybe just coincidence?
I notice that the idle valve houses a water coolant fitting on its side where I suppose the valve operates differently as the engine temperature increases? maybe I should'nt rule it out just yet.
I'll get it all back together tomorrow and hopefully have eliminated/identified more bits.

shane

[Sharpen]

Well I've run the beat a week now and it seems fine now (thought I'd give it a week just to make sure)- whats changed to cure this problem? I put Shell Optimax fuel in it and now it behaves itself.
Atfer reading the posts on here I thought I'd give Optimax a try. So now the stalling has gone away and the idling seems better too.
I've not ruled out the fact that there is underlying fault, I say this because during warmup now there is still a period where the idle speed is uneven (for about 5 mins) but during this stage I can bury the throttle and the engine picks up as it should, instead of stalling and not restarting.
Thanks Jerry and Midship for your suggestions (Jerry I'd already had the fuel pump relay apart and reflowed joints etc) I agree with you both that there is a rouge sensor putting out duff info during the warmup phase.
For now though its working

[Jerry]

Thanks' for the feedback. My son Joe filled his beat with Optimax yesterday. He has not yet done much running but I will let you know how he gets on. His problems sound very similar to yours.
If Optimax does cure your problem, could it be that it contains some additive to clear injector gumming?. I understand Honda and other manufacturers have suffered from this problem.
I have just taken my old relay apart. It all looks fine. The contacts on both solonoids look perfect. I will put it back together and try it in Joe's car. That is if it still works after my soldering!.