Engine Seized help?! 2.0 GE valve stuck down

[AshC]

>> Distributor is an elec so no points/ condenser.
Ah OK. As often discussed some of these electronic options are not the most reliable, so early life issues could be a problem.


>> I’ve ordered a new TS2 to try and no only tested at ambient. Have you any more information on that test as I only have the Bentley

To be honest, the easiest thing is to get the bus warmed up and then turn off the engine. Then just disconnect the TS2 from the connector to the loom and check the resistance, out of circuit, to ground and compare with the Ratwell chart.

But, with a meter set to voltage you can poke into the connector and measure voltage in-circuit to ground with the engine running. At cold maybe around 8 volts and at hot around 2 volts. I wouldnt worry too much about the numbers - mostly its not 0 or 12V and it is reducing with temperature.
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- 79 CA FI Bay Window Bus
- 92 Mk1 Golf Cabriolet

[Jackrobbo]

I’ll try and find an original distributor unit in the UK.

That’s cool I’ll give that a go

Thanks

[Jackrobbo]

https://youtu.be/qrwk641tL-4



Please see video for running issue any help would be massively appreciated this is when idling hot after 5 minutes

[Wildthings]

Make sure the flap in the AFM is moving. Also see if you have vacuum to the can on the distributor while this is happening.

[AshC]

[Jackrobbo]

I've changed the ts2 sensor I thought it had fixed it as it idled for ages and seemed perfect until it did the chugging out again. it did make a bit of a rich popping this time though.

the timing stays as where it should.

could the afr be too rich?

I don't really want to start prying the lid off the afm

[AshC]

I cant help as to whether richness might be the problem, but I don't think you are at the point of trying to adjust the AFM on the inside or adjusting the mixture screw - especially not without a gas analyser.

As it is, you'll probably find the AFM lid comes of with very little effort after 40 years and has been off before - mine fell off! With the lid off you'd be able to do what WildThings suggested too i.e. if the wiper inside the AFM moves then the flap is moving. You could also check if the carbon track is in good shape or not.

At the end, you took it apart after a valve drop and put it all back together again. So it still seems likely that assembly/disassembly things (vacuum, connectors, wires etc..) are high on the list? And of course there's the new heads/valves install and setup in the mix.

About the timing, is it advancing when you rev it up?
_________________
- 79 CA FI Bay Window Bus
- 92 Mk1 Golf Cabriolet

[Jackrobbo]

[Jackrobbo]

Busy afternoon, smoke tested the vacuum system from the top of the S bend. I found 3 leaks, the oil filler cap, the PCV/breatherbox seal was missing. Then finally the throttle body stem seal on the butterfly shaft. This one isn't too bad mind, and I don't think I can sort that without pulling it out.

The other 2 were pretty major leaks.

The PCV wasn't doing anything either, I cleaned it, tapped it and blew it until the diaphragm wouldn't allow me to suck too heavily through it ie. It wouldnt pull off the s bend but would blow into it? which id assume is right?

I also blanked off the vac hose into the PCV and smoke tested again, I was able to hold a pressure in the circuit with this sealed off so I can comfortably say that even with the tiny leak out the throttle body stem that's well sealed.

The only part I haven't been able to test is the brake booster after the nrv as I was blowing from the intake side. so that wouldnt get smoked.

When I went to start the bus after fixing these leaks it would not run, I had to lean off the afm 4 turns just to get it to run.

It ran really nicely the best it has yet until again it started hunting and died, although this time It spent a lot longer hunting.

I have also removed the cover from the AFM, Im not sure but there are 2 arrow heads where I assume the metal lever is meant to be aligned with at both ends open/ closed mine seems to be 3mm further to the closed side. I wonder if this is shutting off the fuel pump when its idling but I haven't ran it with the cap off yet.

My thoughts are,
Vacuum:
blank off the PCV line and try running with the PCV to atmosphere just to rule out that it could be the PCV line that is causing me the hunting issues.

Disconnect the brake booster and smoke backwards from the front of the van to make sure I have no leaks under the van that's been pulled into the manifold.

If I had to adjust the afm screw after resealing the PCVbody and Filler cap maybe these issues have always been present and isn't actually the issue although I have obviously improved things. What else could be causing stalling/ hunting at idle.

[SGKent]

do not use RTV to reseal the afm unless it is the special electronic kind. The acid fumes from regular RTV will damage electronics.
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“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[AshC]

I'm out of my depth at this point : ) I would aim to eliminate the booster hose as a source of vacuum leaks.

Couple of new random ideas:

I remember you checked the FI engine bay grounds - is the transmission to frame ground strap in good shape too with clean attachment points?

Did you pull the AAV and check it opens and closes? The electrical part is really just a speed-up assist to the engine bay heat so an ohms reading is enough on that. Then if you stick the valve in the freezer it should come out mostly open when you look through it. Then if you warm it up gently (hair dryer...) it should close completely. If its stuck one or way or the other it will make it hard to setup the engine around it. Again though not obvious why this would be a new issue...
EDIT: it should have been found by your smoke test but check the rubber elbow at the intake side while this is out.

You could do the various ohms tests on the AFM from the troubleshooting guide if you didn't already and the running test WildThings suggested now the lid is off.

But, my best guesses (and to clear they are not worth a lot) would still be some kind of leak, something going on with the spark or maybe fuel pressure (again, why now?)
_________________
- 79 CA FI Bay Window Bus
- 92 Mk1 Golf Cabriolet