Itinerant Air-Cooled

slow.bus wrote: start happens on my second attempt ... 1 hr after 1st trying. silly

That is silly.

Cold Engine First Start:
Thursday - Just as you crank engine with starter, try progressively depressing accelerator to floor. You of course release the accelerator as the engine hits 1,200 rpm
Does this help?

Friday - As you just crank starter, press accelerator to floor / release immediately (while engine is rotating!).
Does this help?

Saturday - buy a Chevy Volt
Does this help?
Colin

I have / had tried pumping or pressing the gas during the "1st" start attempts - at present, no impact or improvement.

Regardless, I'll try it out. Luckily it's the weekend (and Friday is a holiday in Canada) - so I can do a few tests a day and will continue to "add air" to idle. Will also sub in stock AFM and monitor what it does in the current conditions.

A Volt, eh?

slow.bus wrote:I have / had tried pumping or pressing the gas during the "1st" start attempts - at present, no impact or improvement.

Pumping the accelerator with a fuel injection car is . . . silly. We are not pressing "gas" we are pressing the accelerator **which gives more AIR** . The single press/release with engine rotating is just to free the flap a little.

slow.bus wrote: Regardless,
A Volt, eh?

oh ... I was supposed to depress the "air pedal" ...

I have a lot to learn - but understand those mechanics :)

Appreciate all your help,

had one more day of cold'ish weather - but now it is warm enough that things are working much better.

on the cold night (and next cold morning), I tried some various throttle position starts

-- to the floor, no go
-- 1/2, no go
-- to the floor, release at cranking - no dice
-- 1/4 to 1/3 throttle, seem to fire excellently ...

I think I still have some room to lean out idle, and will test as much as possible, but I think the pending weather is resolving my issues - at least for the next 6 months or so.

Thanks again,

Just for closure - in case others read this thread ... which is now alot of me talking to myself ...

I had a thought late at night about the fuel pump "switch" in the AFM ... I adjusted it months ago when I originally richened the mix with the swiper ... and never set it back when I have since leaned things out.

I put it back "closer" and surprise, surprise ... Fired up on the 1st try.

Still not sure why "second try" kept working for me ... but care alot less ...

slow.bus wrote:Just for closure - in case others read this thread ... which is now alot of me talking to myself ...

I had a thought late at night about the fuel pump "switch" in the AFM ... I adjusted it months ago when I originally richened the mix with the wiper ... and never set it back when I have since leaned things out.

I put it back "closer" and surprise, surprise ... Fired up on the 1st try.

Still not sure why "second try" kept working for me ... but care alot less ...

Should not have had an effect . . . during cranking, the little red/white wire from the starter solenoid spade connector (under the black/red command wire from the ignition switch) turns on the fuel pump during cranking. The engine fires under starter operation, the air flow meter then takes over.

Just for edification, do you have that little red/white wire plugged into your starter solenoid?
Colin Congratulations

hmmm

I have never messed with the wires in the AFM - and I do not think anyone else had it open before me - so those things should be "stock." I cannot check right now, but never saw anything disconnected.

When the car is not running and the AFM is stationary - there is that "gap" between the fuel pump contacts ... it was about 1.5 - 2mm.

I set it back to about 1mm (likely less) and it fired up right away ... 1 good start is not a trend ... but I had had no luck in days starting it (on the 1st try) despite warm weather.

My theory over the winter was that the engine was too rich to start in the very cold, as it showed a 10-11AFR when I would eventually be able to start it - hence my original questions. But as I leaned out and adjusted that ... I never re-set that arm by the fuel pump contacts. Perhaps there was not enough suction to keep it open at cranking in the cold ... I really have no idea anymore ... perhaps alot of little things ...

slow.bus wrote:hmmm

I have never messed with the wires in the AFM -

the little red/white wire from the starter solenoid spade connector (under the black/red command wire from the ignition switch) turns on the fuel pump during cranking.

This wire is not inside the AFM. It is plugged into the starter as written above. it goes to the double relay.
Colin

Hello,

All wires plugged in - and all issues back to normal ... seems I was drunk on warm'ish weather and a single good start.

For the last 2 weeks, same issues as before (only starts on 2nd try ... 15-30 minutes later).

I have simply been living with it - go outside, "try", come back in 15-30 minutes, start - drive away - enjoy.

Only time it has started on its own (1st try) since are when it is over 20 Celsius outside

Because of that I went back to the basics again this weekend and checked the temp II. All original checks were in the garage in very cold weather. It's still in official spec, but I checked it against a few spots on the "curve" from ratwell. I tried outside a few times and checked vs. the CHT's and it seemed close, but higher ... so decided to take remove it and bring it inside for a few hours - away from the camper.

At a solid 20 Celsius / 68 F it had a resistance of about 2500 ohms, in spec, but higher than the number from ratwell ... would that be enough to make a difference and cause the start issues?

slow.bus wrote:Hello,

All wires plugged in - and all issues back to normal ... seems I was drunk on warm'ish weather and a single good start.

For the last 2 weeks, same issues as before (only starts on 2nd try ... 15-30 minutes later).

I have simply been living with it - go outside, "try", come back in 15-30 minutes, start - drive away - enjoy.

Only time it has started on its own (1st try) since are when it is over 20 Celsius outside

Because of that I went back to the basics again this weekend and checked the temp II. All original checks were in the garage in very cold weather. It's still in official spec, but I checked it against a few spots on the "curve" from ratwell. I tried outside a few times and checked vs. the CHT's and it seemed close, but higher ... so decided to take remove it and bring it inside for a few hours - away from the camper.

At a solid 20 Celsius / 68 F it had a resistance of about 2500 ohms, in spec, but higher than the number from ratwell ... would that be enough to make a difference and cause the start issues?

Do not focus upon components that work correctly when warm. Components that are designed to work when cold are your issue. Have you tried the various accelerator positions during first start 1/4 to 1/2 way, did you say?
We have a poor atomization of cold fuel and inadequate air and only unlikely maybe an ignition system that is not quite healthy enough when cold.
Colin

Amskeptic wrote:Do not focus upon components that work correctly when warm. Components that are designed to work when cold are your issue. Have you tried the various accelerator positions during first start 1/4 to 1/2 way, did you say?
We have a poor atomization of cold fuel and inadequate air and only unlikely maybe an ignition system that is not quite healthy enough when cold.
Colin
Colin

Thanks again.

The weather finally seems to be staying warm here - so my issues are fading and hard to tell improvement from my changes from improvements due to overall temperatures going up ... might even hit 65F today ...

Ignition is stock (points), but all parts new within the last 12 months - points / condenser / plugs / cap / rotor etc new this winter. Sparks from lead and plugs are all bright blue

I have richened up the idle / start and increased the air flow via idle and start is better ... combined with a bit of throttle (about 1/2). For the last few days I can start without waiting 15-30 minutes ... usually fires second try, sometimes even get some spurts and cough's 1st try.

I re-checked the aux air by blowing through it and it's open when cold and closed when warm - so air is getting through there as well.

One seemingly odd observation. I removed the Temp Sensor II to test it, and when I re-installed it I left off the washer that was originally between it and the head (about 1MM thick, because I dropped it and could not find it until later). All my AFM's are now 1+ "units" below before ... cruise from 14.6 before to 13.6 now... start from 11.5 to 10.5 etc. I ordered a new one, and will compare the two later (outside of car)

slow.bus wrote:Temp Sensor II washer deleted and AFM's are now 1+ "units" below before ... cruise from 14.6 before to 13.6 now... start from 11.5 to 10.5 etc. I ordered a new one, and will compare the two later (outside of car)

Might be a change in grounding resistance. Clean shoulders on sensor and clean head seat. As you KNOW, the greater the resistance, the more enrichment. That washer just slows down the resistance drop during warm-up, to extend cold/cool enrichment by a minute or so.
Colin

New sensor and old sensor had same resistance - and when installed again with washer - no change in AFR - so must have been some other resistance as you suggested. I have put things all back close to to stock, and started again - too many changes to account for.

To get closer to the original topic area, and not my own trouble shooting - what do you recommend for possibly changing timing to compliment a change in AFR (from about 15.5 cruise to 13.5-14 cruise) - assuming all else held equal?

I have heard / read about advancing for richer, but recall you indicating 28 all in (vac unplugged)? Should someone change advance after richening mix?

advancing the timing past the suggested marks will raise your head temps, and fast. every motor not being equal, I wouldn't rule out playing with the timing a little to see what the numbers tell you - but from what ive seen advanced timing gives more power and too much heat along with it.