interesting comparison between 113 and '61 Corvette with FI

[dsayars]

My cousin has a limited edition '61 Corvettes with mechanical fuel injection, a system similar to the 113. He bought it new and has  kept it mint,with very low miles. Nevertheless, it starts exactly like the 113 does--starts and dies twice, then third time's the charm.

His understanding is that this is unavoidable with the mechanical FI systems of that time because of modern fuels, and no additives are known to help. Is anyone out there informed on this subject?

In any case, it was nice to discover that my 230SL is doing no worse than this low-miles mint Corvette. (At least when mine is behaving normally, i.e., in Spring and Summer. See my topic about spark plugs.)

[Via Manci]

I think that "comparision between 113 and '61 Corvette" is a poor choice of words.  There is no comparison!

[waqas]

Not sure about your cousin's explanation.  

As another data point, my 1966 250SE coupe with the identical setup as a 250SL: cold starts are successful 100% on the first try, and hot starts are successful about 70-80% on the first try.  <knock on dash wood>  

[Peter van Es]

I have 100% and 100%... but it's all in the technique... follow the cold and hot starting routines in the user manual exactly.

Peter

[al_lieffring]

The reason the Rochester fuel injection system is so rare is because most of them were discarded and replaced with a Holley 4 barrel carburetor.
If the sedan carburetors were just a bolt on conversion for the Pagoda F/I system, I imagine that many of them would have suffered the same fate too.

[Iconic]

My cousin has a limited edition '61 Corvettes with mechanical fuel injection, a system similar to the 113. He bought it new and has  kept it mint,with very low miles. Nevertheless, it starts exactly like the 113 does--starts and dies twice, then third time's the charm.

If it took 3 attempts to start the 113 cars, then they would have sold much fewer than they did ...... and then they would be even RARER than they are now.

Since I rescued mine from the POs garage, mine starts first time, every time (I say this thankfully.)

[abe280SL]

After installing a new solenoid, cleaning the openings on the CVS, and replacing one of the pressure vaulves on the transmission which activates the solenoid.... I  can now start the 280sl on the first try.  Unfortunately, it took 15 years to trace the problem(s).  It was thanks to this site that I was able to it. 
abe

[dsayars]

After installing a new solenoid, cleaning the openings on the CVS, and replacing one of the pressure vaulves on the transmission which activates the solenoid.... I  can now start the 280sl on the first try.  Unfortunately, it took 15 years to trace the problem(s).  It was thanks to this site that I was able to it. 
abe

I had the old dribbling CSV, too, now fixed. You say a new solenoid. Do you mean the starter solenoid? Was it drawing too much current? That would normally produce a cranking problem and a high voltage drop to the ignition. Is that what was going on?

[Witt]

......purists please stop reading, but my "under-the-dash-cold-start-button" works like a charm. 

CHEERS !
WITT !

[jacovdw]

Funny you should say that Witt...

The previous owner butchered the cold start system of my car and fitted that notorious "under-the-dash-cold-start-button" as you so elegantly put it. Sure it was easy to start, but annoyed the heck out of me.

After fixing a leaky cold start valve and extensive transplant/reconstructive surgery to the cold start system, she now starts on the first attempt every time...

[philmas]

Never EVER had a cold start problem!
But generally takes two attemps when hot, getting better whith full throttle when cranking (as recommended ?)

[ejboyd5]

My cousin has a limited edition '61 Corvettes with mechanical fuel injection, a system similar to the 113. He bought it new and has  kept it mint,with very low miles.

The Rochester fuel injection utilized by Chevrolet was an entirely different animal and was not "mechanical fuel injection, a system similar to the 113."  The differences in design make troubleshooting comparisons useless, but a Rochester unit can be made to run and to run well - it just takes time and experience.

[jacovdw]

Also the Rochester fuel injection system is a far simpler system than the 6 plunger pumps used on the pagodas...

Basically the heart of the Rochester system's control unit was a spill valve that returned to the tank a certain fraction of the fuel delivered by an engine driven gear-type pump.
The pressure delivered by the gear pump rises with an increase in engine rpm's to a max of about 200 psi.

The position of the piston in the spill valve was determined by two diaphragms. One is connected to manifold vacuum and the other to a single large metering venturi that fed the air box or plenum.

A system of links and rollers linked movement of the diaphragms to the spill valve piston which in turn open/close radial ports in the spill valve sleeve.

[Shvegel]

From experience I can safely say that the reason the Mercedes system didn't get replaced like the Corvette unit is because it worked and stayed in tune. After setting mine up I didn't turn a screw for 3 years and 30K miles until the car came apart for restoration.

I did have the warm start issue as well but after studying the system and it's descendants I modified it so it now starts beautifully.

[abe280SL]

I had the old dribbling CSV, too, now fixed. You say a new solenoid. Do you mean the starter solenoid? Was it drawing too much current? That would normally produce a cranking problem and a high voltage drop to the ignition. Is that what was going on?

No, the solenoid on the CSV that opens up and allows the fuel to spray.
abe

[Eryck]

My car starts first time cold with no problems.  Even after more than two months without driving it.  Warm start, well, no problems as well.  Max is two tries. 

Can't compare with my 63 Corvette since it's a carb, not FI. 

[sctripp]

I turn the key to the first position, allow the fuel pump to run for about 45-60 seconds, depress the gas pedal mid-way down and she fires right up; even after sitting for 1-2 months.
Stan

[Witt]

Funny you should say that Witt...

The previous owner butchered the cold start system of my car and fitted that notorious "under-the-dash-cold-start-button" as you so elegantly put it. Sure it was easy to start, but annoyed the heck out of me.

After fixing a leaky cold start valve and extensive transplant/reconstructive surgery to the cold start system, she now starts on the first attempt every time...

All my UTDB does is activate the CS relay by connecting it to ground only as long as the starter cranks, avoiding flooding the engine. Of course this is the job of the Thermo Time Switch, mine is faulty so I disconnected it. Only one single wire goes from the button to the relay, everything else pertaining to the cold start system remains stock.

 My cold start procedure is as follows: turn on the ignition, wait until I hear the fuel pump energising the system, reach under the dash and press the button with my left hand and turn the ignition key with my right hand to start the car, relies both as soon as the engine fires up.

This may sound cumbersome, but it really is not and I am in no hurry.....and works each and every time when starting from stone cold. I have no hot start problems.

CHEERS !
WITT !

PS: More confessions, I have the same setup on both my other two fuel injected cars, a 1986 VW Jetta and a 1979 VW VAN......