I have run out of ideas on this problem. Looking for creative minds.
I have a modified 61 320 unit on an LT-1 350/370HP. I have been chasing some minor issues and thought I had it sorted out.The latest issue was a stuck float that caused fuel to flow out of the fuel meter vent. I replaced the needle and seat and rechecked the float levels.
I took the car out today for a drive in the spring sunshine and using a tailpipe mounted broadband AF calibration unit I drove to check the economy stop and the power stop. The car idled beautifully cold or hot and was pretty close on AF settings. I drove it home to make final adjustments and as I pulled into my shop it began to run rough and died. I thought no problem I just need to adjust idle settings so I tried to restart it. It spun over normally but would not start.I checked ignition and it's good.so I loosened the nozzle line to see if fuel was getting to the injector nozzle. No fuel. So I thought maybe the shutoff solenoid had failed in the closed position. I made sure there was power to it ,there was. I then connected and disconnected the power to the solenoid without the engine running. i could hear it clicking so my assumption is that its good. This led me to the pump drive axle. I pulled the cable housing to see if the drive cable was broken or if the distributor drive was broken. I installed the cable without the housing to watch it and it turned fine. I don't know where else to look.Any ideas??

 

Couple of thoughts, Jerry:

- Next time you have the fuel meter lid off, examine the float. Look at the front, lower, inboard corner. If there is a shiny spot there, the float has been rubbing on the inboard wall of the fuel meter. If that's the case, then that's likely the cause of the bowl overflow and it will happen again unless you fix the problem.




- Regarding the engine shutting off.....
1. a fuel bowl overflow will cause this due to an overly rich condition. Was there fuel on the adapter plate?
2. Another possible cause would be either a missing support spring under the spill valve or a support spring which is too weak to hold the spill valve in position.
3. If your fuel meter still has the internal anti-siphon check valve, and I don't think it does, if that check valve fails or is blown out by way of fuel pressure, engine will stop.
4. If the ratio roller loses its roller or fractures, engine will stop.

You've pretty well ruled out the other likely FI-related causes.

 

I checked the float and didn't see any rubbing.
there is a pretty stout spring under the spill valve
No internal syphon
would the nozzles be dry under cranking if the roller was missing or damaged?

As silly as it sounds I may be down to an obvious problem. Maybe it ran out of fuel. The gauge was reading an eighth but i have no long term experience with this gauge. I'll check that tomorrow.
What a long strange ride this has been.

 

Oh, yes!!!
Um, yeah. The same thing happened to me once and I sure felt foolish when I realized what the problem was.I'm sure Jerry G. (not you, the other one) agrees.

 

It WAS the fuel. I put 5 gallons of fuel in the tank and cranked it over for a minute and VOILA it started and idled beuatifully. I'm embarrassed that I made the same mistake Corvette folks have been making since 1957, if there's a problem it must be the GD fuel injection. So many ended up being taken off for no real reason. I should know better I vintage raced for years a Rochester on my 64 Corvette. Oh well. happy it's something simple.

 

Jerry
I did the very same thing when I rebuilt my FI unit years ago. It started and ran, but then died. The only way I could start it was spray gas/starter fluid in it. My wife came out and asked me if it was out of gas. I spewed and fumed that of course it wasn't out of gas, (what the heck would she know about FI) I looked down in the tank and looked like there was plenty of gas in there. Butttt later on I put 5 gallons in and it started and ran. Crow doesn't taste very good but I did didn't learn very well. Similar thing happend to my 64 but this time I didn't spew and fume, I just put more gas in after she reminded me of previous advice. Have I ever lived that down???? Nope.
Gary

 

Same thing happened to me at least twice. I thought I had more gas than I did because of a combination of a bad fuel sender and bad fuel gauge.

 

BTDT in my 1960 about 50 years ago.

 

Jerry - perhaps you can answer this question. I have been trying for years to get an answer.

The '61 FI engines were equipped with the "big port" ...461X heads that have larger inlet ports than all previous "small port" 283 heads.

So does the '61 FI manifold and adapter plate have larger runners to match the big port heads or is it essentially the same as previous FI manifolds whose runners matched the size of the "small port" 283 heads?

Duke

 

I have the original 461X heads but they were poorly cast and have cracks on the bolt bosses. To answer your question the intake ports and the FI adaptor are very well matched. My setup is an old long block I purchased in the early 70s to go BP road racing. An LT-1 with angle plug heads. The intake adaptor on the FI matches up well with this head also. If you'd like any measurements off the old 461X I have it sitting next to my desk in the shop. Jerry

 

Thanks - no need... sounds like the '61 FI manifold and adapter ports were matched to the new big port heads. That would make the '61 manifold and adapter unique to that year.

Duke

 

Also may account for the HP increase from 290 to 315 on the SHP engines.