Help! Bus stopped and won't start / stay running

[SethC]

77 Bus, Stock FI

Was headed out on my weekly commute from Northern Washington to Seattle, I had traveled all of about 3 miles when the bus engine suddenly died at 60mph. It wouldn't restart. I got the red lights and the starter noise, but no coughing , or sputtering...

Initial inspection of the engine compartment revealed that the interior of the distributor cap was coated in black dust and the center point that contacts the rotor was missing... smoking gun? easy fix? ... nope. I had a spare cap and rotor on me, so I swapped them in and regapped the points. no luck. I changed the condenser and checked for spark at the coil... still wouldn't start.

Got the bus towed 3 miles back to where I started...

Today I:
hooked up a test light and verified that the light came on for each plug,
Re-verified spark at cylinder,
pulled #3 plug and verified spark
pressed the flap in the AFM to get the fuel pump to run
put a fuel gauge on the rail and verified about 34psi
I scratched my head, looked at things to try and find something amiss, cleaned the FI grounds...
probably said some unkind words...

Pretty sure at this point that the distributor cap was a coincidence...?

Then I remembered that over the last week or so, intermittently I had the engine die while starting and had to give it a little gas to get it going... so I put the accelerator pedal all the way to the floor and then tried to start...

It coughed ,spluttered, and eventually started, although I had to keep my foot on the gas to keep it alive. As soon as I took my foot off the gas it died.

I took transit to Seattle so that I could get back to work, but I will be able to look at / work on the bus again Saturday, so any suggestions of test to run or things to look at would be very much appreciated.

Potential red herrings, possible data:
Last week my alternator died... I replaced it. That was painful, I'm not sure if it has any bearing on the current issue... but it is data.
A few hours before the bus died Sunday night, I replaced the fuel filter. I've had the bus less than 6 months, and didn't know when the last time it had been changed, and I had a little down time, so I figured, why not? I had 34 psi at the rail with the engine running before and after the filter change.

Again, any help pointing me in a direction to look/check/test would be great.
_________________
- '77 Transporter (78 engine?)

[Brian]

I promise that I will read your whole thread in a few, but as soon as someone says wont run / fuel injection I just say its a vacuum leak.

Running fuel injections is usually not running because a hose came loose or is just worn.
_________________
Wash your hands

'69 Bug
'68 Baja Truck
'71 Bug
'68 Camper

Only losers litter

[Wasted youth]

Disconnect the wire from the wiring harness going to the TS-2 sensor on the cylinder head. Clip a test lead to that and frame ground. See if that changes anything. When the TS-2 goes bad one symptom is terrible running, with difficulty keeping it running and very hard to start.

[busdaddy]

Did you reset the timing after gapping the points?
_________________
Rust NEVER sleeps and stock never goes out of style.

Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!

Слава Україні!

[420GOAT]

ohm the injectors. check if they have the proper resistance, and check the spray pattern.
_________________
once you realize im not impressed we will get along just fine

[Wildthings]

Old hoses come off as mentioned, while wires push back out of plugs. You may be able to hear a bad vacuum leak. An engine with a bad vacuum leak may cold start fine and then rev way up and then die. A bad TSII will cause the engine to run worse at it warms up.

[SethC]