Cold Start Issues

[PaulAV]

Huw, you were wondering why a leaky exhaust would only show symptoms when cold, because once hot it might not leak, only needs a small gap for air to get drawn in then once warmed up and everything expand the gap could quite easily seal. It's not unheard of.

[Rotary Potato]

Ben has bet me a pint it's battery related and it'll fire straight up with a jump.

He thinks the strain of spinning the engine is meaning the coils don't have enough power to ignite the mixture, partially flooding the engine, hence why it then starts with fuel cut activated.

To avoid "doing a FrankenRex" I'll wait until the weekend when I'll have both daylight and time to help me steer clear of any sparky misadventures.

Working from home today, so cracked out the jump leads and ...

Ben owes me a pint!

Absolutely no difference.

It will fire eventually, but still very difficult and does it after a long crank followed by flooring the throttle to activate the fuel cut.

[ChrisHolmes]

Exactly what mine is doing but we are pretty sure its compression as it tested at low 5 the other week.
Strangely after failing to start at Snetterton after several long attempts I walked up to the car, turned the key and vroom it started instantly! This happened twice and was a real shock to everyone!
Going in for an engine transplant on Saturday so I hope the issue is not there once that is comleted!

[SeeJay]

Huw..when you have THIS starting issue,then you can moan

[PaulAV]

Seejay could it be the fuel pump resistor failing? I believe it operates on start up to ensure the fuel pump supplies the correct pressure, but once started its not used, just figured if it's going bad it might restrict the fuel pump operation when it shouldn't

[SeeJay]

Paul,I checked this out by bypassing the resistor - cut the connector off anothe rresistor,and bound the wires together - and it made no difference..

However,I've ordered another resistor so I can fully eliminate that component..

..and yes..this is really getting old now..

[PaulAV]

Just reminded me slightly of the old ballast resistor issue I had on a mini I think, when the key was in the starter position the engine fired but when you let it go the engine died due the resistor failing. I know its not the same but it seems like something is cutting out once the engine fires.

[sKenDread]

Heya Huw, any news since last month? I've only just seen this thread.

08 231 West Midlands

[Rotary Potato]

Heya Huw, any news since last month? I've only just seen this thread.

08 231 West Midlands

Hi mate.

Not huge amounts of progress. Ben has said the next step is to test the coolent for possible leakage into the engine. Nick has a kit to test this, but I just haven't had any time recently to book in to go see him.

However, from using the car, if you leave it for anything up to 90 minutes after a hot shutdown, it fires up on the first turn of the key. Leave it 2 hours or longer and you get the endless cranking. There doesn't seem to be a graduation of the issue getting worse the colder the engine is, more of a binary fine-fooked line between 90 mins and 2 hours.

That feels to me very much like it's sensor/electronics related rather than anything mechanical. But I'm far from an expert!

[sKenDread]

Bugger dude, I'm wondering if it's sensor based too but I don't know.

It seems like it's over fuelling when cold.
Or not enough air getting in.
Or not firing right when cold.
Dirty ESS?
Or maybe water getting in.

Your plugs seemed to look ok at Twycross last meet. And to be honest I was pretty nervous getting mine started that evening.

I spoke to Mick in Coventry that following week. He said to get the coils checked out again, as ignition being the potential culprit. Although mines probably due for a rebuild, he still thought the coils looked a bit knackered (D585) cooked???




08 231 West Midlands

[PaulAV]

Mick had a collection of 585 style coils hanging up on the wall, they are not infallible, but they are a big improvement on mazda coils, not all 585 coils are built to the same standard just like mazda coils if they were brought from the Internet they could be cheap ones, unless you know they are decent.

[13Black]

Revs have a similar death box of D585s of various types, and I think Ben did mention something about what they do to theirs differently. Even if I could accurately remember, it wouldn't be my place to say - but certainly seems like some are better made than others.

Keni I really think your engine is around the 5.0 kg/cm2

[sKenDread]

Yeah Nick, I went to see Mick for the rebuild. I'll get it done pretty soon now.

Still wondering about this cold start though.

Huw have you tried another full set of ignition?




08 231 West Midlands

[Rotary Potato]

Plugs are good.

I'll check ESS, but assume Rotary Revs would have checked/cleaned at rebuild time. Regardless, struggle to imagine a scenario where it's fine everywhere except stone cold starts.

It feels like an air/fuel issue ... but need to eliminate everything else first.

I probably need to book some time in with Mr 13Black, get the coolent test done, and work through some fault finding with him (along with some other bits'n'bobs like fitting my braided brake lines).

[MARKTHOMASBRAND]

Perhaps fuel pressure is ebbing away after a lengthy period of sitting

Just thinking out loud....Seejay's starting problem is bugging me too

Feel your pain guys

Regards,Mark.

[Ainmhidh]

Are you still running the rice krispies map Huw?

[Rotary Potato]

Might have to check fuel pressure Mark. Thanks.

Alan - it lost its pops'n'bangs (along with its ability to start from cold!) when it went for its mapping session up at Revs.

[Ainmhidh]

You should get Ben to stick that map back on - it might be the only one it's happy with now it's had that experience!
(Anthropomorphic bridgeport?)

[13Black]

I'd be quite surprised if they've changed anything on the map that would affect cranking - but then I don't do mapping and I am a bit of an idiot.

[Ainmhidh]

I wasn't being entirely serious (Parker serious?) Must use more smilies to convey my intent!

[13Black]

I actually did mention it to Huw before that it would be possible for me to flash the previous map onto it at the next Midlands meet (balls, still need to organise that actually) but that would require Ben sending me their maps and he's not that daft

Either way, quite happy to have a nose at a few things at the next meet, usually seem to get my hands dirty doing something.

[SeeJay]

I'm over at Nick's on Tuesday to have the HC test done among other things,so it might be an idea to swap the original dwell map back whilst I'm there,as I don't think we've actually tried this..

[13Black]

I don't think we have.

Could also try OEM coils next time it's in for some smoke-n-a-pancake. Should be putting my rig together next week.

[Rotary Potato]

I actually did mention it to Huw before that it would be possible for me to flash the previous map onto it at the next Midlands meet (balls, still need to organise that actually) but that would require Ben sending me their maps and he's not that daft

Either way, quite happy to have a nose at a few things at the next meet, usually seem to get my hands dirty doing something.

Would be awesome if you could mate.

I start getting lost when you need to crack out the electronic spanner.

[13Black]

I have no idea what I'm doing either. Just press Enter and charge people money.