Anyone specialize in VW engines?

[OnionPatch]

I don't come to the automotive forum much (although I'm a longtime DU member) but I hope it's ok if I post this question asking for advice.

My husband and I bought a '78 camper bus that was in great shape except the engine was shot. So he obtained an engine from another bus that had been totaled that had belonged to a friend. That bus had been hit in the front and the engine was not damaged (that anyone could tell.) It ran fine before the accident. It's a '77 2-liter engine with fuel injection.

So my husband put it in and also new plugs/wires, coil, vacuum hoses, fuel and air filters (and a whole lot of other things) and has had the timing adjusted and everything he could think of. It's running and seems to be idling fine but when he accelerates, it stalls every time. Given that it has new just about everything, it's hard to figure what's wrong. It's getting pretty frustrating and we would just take it to a shop if we could just get it to run. We may have to just have it towed there, but we thought we'd try a little more first.

Can anyone here think of what might be the problem, what we might check? Any advice or insight is appreciated. We sure would love to get this thing running so we can start enjoying it.

[Gold Metal Flake]

1. Since it is FI you probably have an issue with the fuel injection rate.

I assume that the injector pump or pressure regulator is not responding to the increased demand for fuel, so it goes lean and dies.

I am familiar with the late 70s VW diesels but not the flat 4 water boxers. Also I am not familiar with the VW gas FI system. I'm about useless in this thread, but at least I can keep you company until someone with a brain comes along, LOL.

Have you searched for a friendly VW forum? I am sure there are several bus forums out there as popular as they are. Google the correct model name and the word forum to get started.

[OnionPatch]

2. Thanks so much for the reply.

We did what you said and posted at TheSamba.com. He's been going to that site for ages for info, but didn't know they had a forum. We had a lot of responses there and one of them had the answer---It was the plug on the back of the AFM. (Whatever that is...:shrug: I'm no mechanic.) Anyway, it's running great now!

Thanks for the suggestion and for keeping me company. :)

[Gold Metal Flake]

3. AFM = air flow meter.

Yeah, that would do it! Without the AFM the system does not know the engine is trying to accellerate.

Congrats on finding the solution! :party:

[OnionPatch]

4. Internet forums are great, aren't they?

I think he probably would have figured it out eventually, he was going over everything and knew it must be some small thing he had overlooked. But I was getting impatient, so I started posting for an answer. It's our camper and summer is almost over! Three day weekend coming up.....We may just get a trip in, after all. :D

Thanks again!