Doug C Young

I am still having trouble adjusting my 65 7017380 fuel injection to a lower idle. I have a 30-30 cam which has been adjusted couple of times to be sure it is correct. Everything in my engine is new & top quality. My 070 distributor has been done professionally by a well known US guru and my 380 unit was completely overhauled miraculously by a Pa guru. I have replaced the throttle return spring with a stronger spring but still cannot get a idle lower than 1400 rpm. I have timing set at 10 degrees advance. It almost seems as there is a vacuum leak somewhere but I am not sure where to start. Any help or suggestions is really appreciated. Thanks in advance Doug Y

MikeM

You need to clarify if the engine stalls if you go below 1400 or if the idle speed just refuses to go below 1400.

What did the Pa flash tell you was maybe wrong?

Doug C Young

Thanks for quick reply Mike. The engine will stall if I get it to idle below 1350-1400. It has lots of power when I hit throttle . I think it is a vacuum leak but not quite sure where to start looking

jim lockwood

Your symptom doesn't immediately make me think of a vacuum leak.

A vacuum leak at, say, the plenum/base plate junction would cause uncorrectable elevated engine idle speed, often accompanied by a shrill whistle.

A vacuum leak in the path of the main diaphragm signal could generally cause the unit to perform poorly overall.


How much manifold vacuum do you measure at the lowest speed at which you can get the engine to run? My hunch? Your 30-30 cam doesn't produce enough.

Jim

MikeM

My first "guess" is a vacuum leak. Maybe in the base plate to the heads, base plate to plenum leg or maybe you cracked a plenum leg when you installed the plenum?

My second "guess" is you do not have a stock grind OEM 30-30 cam and you're not getting enough vacuum.

Third "guess". Did you set timing with the vacuum advance hooked to a vacuum source or did you set timing with it disconnected?

If you set the timing with the vacuum advance disconnected and it won't idle down, bump the timing another 3-4 degrees, hook the vacuum advance back up and see if that helps.

What did the guy from Pa tell you?

PAmotorman

my guess he set the timing with the vacuum advance connected.

MikeM

That would cause his problem.

Doug C Young

I am going to call my FI guru in Pa for quick enquiry. I did set the timing with the vacuum advance disconnected. I have a new Fed Mogul Speed Pro 30-30 camshaft & new lifters. The engine was pulling about 13" of vacuum at 1400 rpm so I am sure there is no problem with the camshaft. I'm thinking maybe I have a intake to engine rear vacuum leak. I did not use the black GM end gaskets but I did use use a good black gasket sealer. Maybe I left a little pin hole with out sealant. I will find out and let everyone know further, many thanks for everyone's assistance. Doug Y

MikeM

Use carb cleaner and/or propane and shoot it around any suspected places where you might have a vacuum leak. Listen for engine speed changes.

Substituting silicone sealer for the rubber end gaskets won't cause a vacuum leak.

John E. DeGregory

Actually Mike the silicone sealer can in fact cause a vacuum leak. Have heard of this issue many times.

Call me Doug as I have no time for this forum chat. Buried with work.
724-832-3786 Call 9 to 5 EST Mon thru Fri. John D

By the way gang the hottest fuel injection being restored right now is a '64. Whew!!!! True story. Later

MikeM

You should have explained how that works before you disappeared. There is no vacuum anywhere near the silicone if you're talking about the adaptor/block end seal gaskets.

tuxnharley

I've used carb cleaner many times, but propane around a running engine? Yikes! You're a lot "braver" than I am!

Plus, I like the tube delivery nozzle on the carb cleaner - lets you aim it very precisely. How do you aim the propane - unlit torch nozzle, or what?

MikeM

Yes. Unchlorinated brake cleaner in the aerosol can works just as well.

PAmotorman

he may be talking about using it on the baseplate to the dog house gaskets. most RTV are not gasoline safe and disolve in gasoline

MikeM

He probably is but that area isn't what was under discussion.

Just wondering if he got the OP's problem fixed with top secret info over the phone?

OP has disappeared.