77 FI intake backfire on start

[Abscate]

[Clara]

[OG Velvet]

**Upate**

Been out of town for a week or so, just getting back to this.

There are two issues.

*Issue #1- What I originally posted about. Backfire on startup through the intake. About every 10th start. I have a strong suspicion that it's a leaking CSV. I have a spare and I will see if that solves it.

**Issue #2- Now much more urgent than issue #1. This shutting off problem.
After my last post I was headed to get a spare ignition switch. I made it to the parts store and almost home (about 10 miles) with no problem. Then all hell broke loose. The bus would start and run, but the second I put a load on it, it died. I limped it into a Target parking lot and spent about two hours swapping out the ignition switch. (which btw I had to use a dab of superglue to keep it in there. I guess the replacements do not have the hole for the little set screw to keep it in place) No change. It got worse and worse. I spent the next 30 minutes babying it home. I got home. Slammed the door. Flipped it off and went fishing with my friends. I really hate sleeping in a tent btw... Took a quick trip for work and now I'm back to fix the issue. I'm going to read through this thread again and try all of your suggestions. If you have more, it would be greatly appreciated!
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'67 13 Window
'77 Westy
'69 Sunroof Beetle
'65 Honda Dream

[SGKent]

points or electronic ignition?
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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

[OG Velvet]

Points. Just checked dwell and it was good
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'67 13 Window
'77 Westy
'69 Sunroof Beetle
'65 Honda Dream

[SGKent]

check fuel pressure. If it is low it can be anything from a plugged outlet in the tank to a bad pump or filter.
_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[OG Velvet]

30 psi and is holding
_________________
'67 13 Window
'77 Westy
'69 Sunroof Beetle
'65 Honda Dream

[OG Velvet]

**Update**

Changed plugs (they were due) cap and rotor

Double checked dwell and timing- (both good)

I've narrowed it down to the problem happening once warmed up. It's acting just like Clara described her issue. So temp sensor 2? I swapped out two used ones I had in my tool box. So three different temp sensors, no change. However, I have yet to try a brand new temp sensor. That will have to wait a couple days being Sunday on Veteran's Day weekend.

Any other ideas?
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'67 13 Window
'77 Westy
'69 Sunroof Beetle
'65 Honda Dream

[SGKent]

with it running pull each plug wire at the cap and see if the RPM falls. See if you have one or two dead cylinders.
_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[OG Velvet]

[Randy in Maine]

Make sure you change out the injector seals and the short hoses while you are at it.

http://www.busdepot.com/311198261a

They used to be $5.

[OG Velvet]

So the brand new temp sensor II did not solve the problem.

I am running on all four cylinders.
_________________
'67 13 Window
'77 Westy
'69 Sunroof Beetle
'65 Honda Dream

[Amskeptic]

[Tram]

[Amskeptic]

[Tram]

[OG Velvet]

Sorry... I didn't see that you fellas had replied...

I just tried Collin's idea. There was one set of pins (second from the right on the plug end) that was a little off. I straightened it with a small screwdriver. I took it for a test drive and I haven't had the problem yet. Granted, I haven't driven this bus for a couple weeks now. I'm going to drive it to work tomorrow and see if it's truly fixed.

Again, thanks for the help
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'67 13 Window
'77 Westy
'69 Sunroof Beetle
'65 Honda Dream

[OG Velvet]

No change.

I have another driver, so this hasn't been terribly urgent. I burned my last AAA tow when the bus left me stranded last week. Engine starts, but as soon as I put a load on it, it just shuts off. This seems to only happen once it's warm. However, after it sits for a couple days, it runs fine for awhile, gets warm, then the problem comes back.

I'm moving on to fuel. I haven't changed the fuel filter. I will take care of that and see if there is any change.
_________________
'67 13 Window
'77 Westy
'69 Sunroof Beetle
'65 Honda Dream

[SGKent]

did we ever adjust the valves to be sure they were not tight?
_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[timvw7476]

This thread seems to have changed into a fuel delivery when at temp issue.
Tired fuel pump/bad double relay are the usual suspects for that fail.