'79 CA Bus - starts, idles, stops, won't re-start

[rallybug]

As the title says, I have a '79 CA-spec bus that, the first time you get into him, starts on the first turn of the key. If you leave him idling, he dies in under a minute.

When you try to re-start, you may be lucky and get him to start and idle again in under 30 turns of the key, but this morning, he re-started at that point, idled for a while with my foot resting on the gas pedal, then died within 20 seconds of taking my foot off the pedal.

When I tried to re-start, he tried but failed, or I just got the sound of the fuel pump whirring.

Temps outside are around 28, but as he did catch and idle, albeit at a raised rate due to my foot on the pedal, I don't think that's a real issue. I took him out for a 30-mile round trip on Thursday up and down the freeway and city streets, and he was fine - on that day, he started first time, idled for under a minute, died, re-started after 20+ turns of the key and then idled fine with me inside the house for 5 mins or so before I left.

Just had his emissions test on Thursday too -

High-speed test (2337rpm) - HC(ppm) = 155, CO = 2.52%, CO2 = 11.1%
Idle test (769rpm) - HC(ppm) = 228, CO = 1.43%, CO2 = 8.4%

I did notice that the vacuum lines weren't set up as per the engine lid sticker when the engine was re-built, but the mechanic said that they are set up as they have found works well for Utah, so no idea on that front, and no way of testing.

Any ideas?

[Amskeptic]

As the title says, I have a '79 CA-spec bus that, the first time you get into him, starts on the first turn of the key. If you leave him idling, he dies in under a minute.

When you try to re-start, you may be lucky and get him to start and idle again in under 30 turns of the key, but this morning, he re-started at that point, idled for a while with my foot resting on the gas pedal, then died within 20 seconds of taking my foot off the pedal.

When I tried to re-start, he tried but failed, or I just got the sound of the fuel pump whirring.

Temps outside are around 28, but as he did catch and idle, albeit at a raised rate due to my foot on the pedal, I don't think that's a real issue. I took him out for a 30-mile round trip on Thursday up and down the freeway and city streets, and he was fine - on that day, he started first time, idled for under a minute, died, re-started after 20+ turns of the key and then idled fine with me inside the house for 5 mins or so before I left.

Just had his emissions test on Thursday too -

High-speed test (2337rpm) - HC(ppm) = 155, CO = 2.52%, CO2 = 11.1%
Idle test (769rpm) - HC(ppm) = 228, CO = 1.43%, CO2 = 8.4%

I did notice that the vacuum lines weren't set up as per the engine lid sticker when the engine was re-built, but the mechanic said that they are set up as they have found works well for Utah, so no idea on that front, and no way of testing.

Any ideas?

You are at the ragged edge of leaving the tight L-Jet parameters for cold start.
Two questions to help us narrow it down:
1) Is the very first start successful?
2) How does bus run when under way cold?
Colin

[rallybug]

You are at the ragged edge of leaving the tight L-Jet parameters for cold start.
Two questions to help us narrow it down:
1) Is the very first start successful?
2) How does bus run when under way cold?
Colin

First start, first turn of the key, no gas pedal etc and it catches and idles, although it dies on a standard idle within a minute.

When I eventually get it running continuously, it seems to be fine - pulls OK, and was fine around town for a couple miles to the mechanic for the safety & emissions tests. Started straight up when he took it in (after 10-15 minutes switched off), and then was fine when I took it up to around 65mph on the freeway for 25 miles or so.

[Amskeptic]

First start no gas pedal catches and idles.

Thank-you.

When I eventually get it running continuously, it seems to be fine -

Thank-you.

See how my editing makes you focus on answering the question?

Repeat after me, "my cold start system is fine."
However, the AAR may be not opening enough. Keep that thought on stand-by. Next time engione is fully warm, make idle as close to a solid 1,000 rpm as possible.
Please check the TS II in the house at 68-72*. We are looking for 2300 ohms or above. I hope yours is the easy one to pull. Check for and tell me if it has a washer?
Colin?

[rallybug]

Will do, Colin, thanks for your help. The TSII wire appears to be attached OK (dark green going through a black connector to the pair of wires that go to the coil), but I shall certainly remove it this weekend and test it in the comfort of the home, rather than outside kneeling in the snow in sub-freezing temps

Are all timing lights created equal? I can borrow my father-in-law's, but it might make more sense to have one of my own

[Amskeptic]

Will do, Colin, thanks for your help. The TSII wire appears to be attached OK (dark green going through a black connector to the pair of wires that go to the coil), but I shall certainly remove it this weekend and test it in the comfort of the home, rather than outside kneeling in the snow in sub-freezing temps

Are all timing lights created equal? I can borrow my father-in-law's, but it might make more sense to have one of my own

We have the finest population of emoticons . . . .

Timing light? Who needs a timing light? Does it run well when warm???? Well? If yes, leave the timing out of it.
ColinYesNoTimingToday

[rallybug]

We have advancement - I went to pull the wire off the TS II, and the wire came off.

The female terminal didn't!

I crimped a new terminal on, add some extra gas from a spare can in case it needed it (odo and my notes were showing around 180 miles - new sender/gauge doesn't work, alas), cranked about 6 times and Harvee idled! I tried adjusting the big screw on the throttle body anti-clockwise (as per the Bentley) but it didn't seem to make much difference to the idle speed

But he continued to idle fine.

I'll try and take him for a run this weekend after getting a full tank of fresh new gas inside him, especially as we have (or should still have!) $2 a gallon off gas from our grocery store loyalty card =D>

Add that to the replacement fresh-air fan (above the engine) bought off TS getting some air through to the dash (feebly, but better than none!), and a successful day!

[Amskeptic]

TS II wire came off.
I crimped a new terminal on and Harvee idled!
big screw didn't seem to make much difference to the idle speed

With a fully warmed engine, turn big idle speed screw clockwise until the speed just drops. This is so we don't have the case where you have four useless turns out that just promote a vacuum leak. Do you have a fully warm 950-1,000 rpm warm idle?
ColinCongrats

[rallybug]

Finally got back out there now that the weather has turned - got him to start, idled slightly high with slight pressure on the gas pedal for a few minutes, then he idled on his own.

Took him for a 10-mile drive - he stalled once at lights after about 4 miles that required 3 turns of the key to re-start, then ran OK, and idled OK when I got home.

I checked the idle speed that I'd adjusted before setting up and it was at around 1050, so turned the idle speed screw clockwise until it dropped to around 950. We'll see what happens.

For the TSII - I presume I need a deep-wall socket of what size to get it out?

[Amskeptic]

stalled once at light after about 4 miles then ran OK.

turned the idle speed screw dropped to 950.

For the TSII - I presume I need a deep-wall socket of what size to get it out?

Dropped idle speed may make it worse. That's OK, report back if it does.

13mm.
Colin