Early 1970E, Cold Start Relay - Not thermal timer.

OK - This is how it's wired from the relay.
Terminal 87 to cold start injector (CSV).
Terminal 30/51 to fuel pump relay terminal 30/51.
Terminal 85 to ECU (plug connector)
Terminal 86 to starter (plug connector - shared with terminal 85).
CSV to ground.

I was able to verify CSV worked by connecting to battery temporarily to hear click. WARNING - don't do this with your fuel injectors since they are 3 volts.
I was able to check for 12 volts from fuel pump relay by turning ignition switch to run. Voltage from ecu varied with engine temperature.
I was also able to check CSV relay by jumpering terminals 85 and 86 to battery, and 30/51 to positive and to check voltage at 87 to verify it worked. Did very briefly. Just enough to verify function.

The problem - corrosion on the terminals/connectors attached to the starter was limiting voltage to 10.5 volts to the connector which goes to relay terminal 86. Lot of carbon buildup.

Now, got to figure out why it runs so rough until it warms up. I'm going to start with vacuum leaks. Timing is good - did that last week. I also need to check my valve clearances. I think those may be a little off too.


Tom

Unless valve clearances are extreme I doubt if they are having an impact
that you would notice in this case. They would be VERY noisy before they
presented any driveability problems. (If the clearance is zero or negative
that COULD be a problem.)
--
George Downs, Bartlesville, Oklahoma, Central US

OK - Never have checked valves before. I just wanted to go through everything. I got this car about 6 weeks ago, and am working thru all the little problems which are beginning to make a big difference.

I'm going to use PhilS's archive info from Vclassics to check/adjust the valves. Also, his write-up on DJet is very good.

Thanks,

Tom

Just to clarify, the CSV does run on 12V -- it the main injectors that run on 3V max and have a very short duty cycle.

As for rough cold running, if you have a consistent idle and good behavior once it warms up, it's unlikely that air leaks are causing problems when it's cold (do check, though). The CSV should do nothing unless the engine is cranking, so that's also not a likely culprit.

The aux air valve provides for fast idle when cold, and the coolant temp sensor provides some extra richness when cold. I'd check those for proper functioning.

Thanks, I have a spare aux air valve I'm going to swap. Temp sensor checks out OK cold and hot, but I read the other post about having a flat spot, so I'll check that too.

Is it predominately sensor II (coolant), or does sensor I play a role in having a rough start too?

Good behavior and idle once warm.

Tom

Check out the Aux Air Valve before installing. I have a bunch of them
that DON'T work. You can check by immersing the bulb in boiling water for a
while and see if the valve closes. If it doesn't close, or nearly close,
it is no good. I've put an aux air valve from a K-jet on my 73 145 but
have not got it running yet so don't know how well it will work.
--
George Downs, Bartlesville, Oklahoma, Central US

Thanks, I did.

Sensor #1 measures ambient air temp and shouldn't be much of a factor, I wouldn't think.

You can check the aux air valve by blowing through it cold, the warming up the motor and blowing through it again. Air should go through easily cold, and it should give you a fair amount of resistance hot, although it won't be 100% air tight.

May I suggest that this test is a lot easier than swapping it and getting coolant everywhere.

8^)

Yes. I've done the test and my replacement seems to work better than what's in place. As fae as I can tell, the installed one is stuck in a slightly open position. It does not seem to pass as much air as the other one. Good time to flush the coolant and put in a new thermo anyway.

Thanks,

Tom