Vapor lock?

[landriopa]

I have a R-1 with an Edelbrock 1406.  If I stop and come back within an hour, it starts hard.  The starter can barely turn over the engine.  Even with a jumper box, it turns slowly for the first 5 to 10 revolutions, then if I am lucky, it speeds up and starts.  My impression is that this is vapor lock and cranking the engine clears it out after a number of rotations.  Am I correct?  And what can be done to minimize this problem?

[Gunslinger]

It could also be a timing problem or even a starter problem.  If the timing is advanced too far it can work against itself trying to start.  If the starter is heat soaked it can act similarly when hot.  

Has it only acted this way since the carburetor was installed?

[Kennie B.]

Slow, hard cranking isn't a sign of vapour lock, instead just what Gunslinger pointed out.  Verify the timing, connections to the battery including the ground, solenoid and the starter itself.  I thought me car was cranking fine but during the engine rebuild I had the starter rebuilt as well, and that did help.

Ken

[Gunslinger]

Check and clean and tighten every battery cable connection...from the battery itself to the solenoid, starter and the ground as well.  Eliminate the easiest first then move on to other possibilities.

[landriopa]

Gunslinger, the car came as a do it yourself kit, as the original owner had taken it apart forty years earlier.  Attached is the photo on Ebay that almost made me not get this car!  It did not come with a carburetor so I bought a new Edelbrock 1406 to install on it.  Therefore I not not have any idea how it ran before the rebuild.  I will recheck all connections, but they were all tight and clean when I last looked.  It only does this when it is hot, if I let it sit an hour or two it starts fine.

By the way, I do not know if there is any correlation, but my vacuum gauge never seems to move much above 10 or below 5.

[Gunslinger]

Not starting only when hot is a classic symptom of starter heat soak.  I wouldn't be surprised if the starter needs rebuilding.  A starter draw test can usually confirm that.  

The vacuum issue could be one or both of two issues...the vacuum hose from the intake manifold connection could be cracked and leaking or the gauge needs to be removed and a drop of oil being put in it.  Some say brake fluid will work or a drop of penetrating oil.  If neither of those helps the engine may have other vacuum leaks.  

[StudeNorm]

You say it came as a "kit" so did it come with the correct HD starter or does it have the standard duty starter?

[landriopa]

As to the current starter.  Although I cannot remember the model, it is a four pole Delco-Remy.  I will get under it Wednesday evening and give the model number.  I will check all the connections.  I do have the battery grounded to the engine block.  I will look into wrapping a heat shield.  I do know that although the gauge shows that I do not have an engine overheating issue, that the engine compartment is the hottest of my vehicles when I open the hood immediately after it running.

When I first put everything together, I found that I was over zealous with painting and the starter would not turn due to the paint insulating it from a proper ground.  A bit of scraping and sand paper worked wonders.

[Gunslinger]

Are you sure it's a Delco starter?  It should be a Prestolite unit.  Engine heat doesn't necessarily mean it has to run hot or overheat to cause a heat soak problem.  What can happen with heat soak is the starter retains engine or exhaust manifold heat due to age or wear and requires excessive amperage compared to cold conditions to engage.  Sometimes adding a heat shield between the starter and the exhaust manifolds will cure the issue.  If the problem is within the starter itself either rebuilding or replacing is the solution.

Before condemning the starter a current draw test should be performed with a cold and a hot engine to verify.  It could still be a timing issue.  An unlikely but within the realm of possibility is a blown head gasket or cracked cylinder head and coolant in filling a couple cylinders and making starting difficult.  That happened to me before but it would usually do so when starting a cold engine as well.

[landriopa]

I just looked at my starter.  It is a Delco-Remy Model 110765 Series 9K21.  When I took it apart to check it and found it to be a four pole starter, I was hoping that it would be suitable. 

I know that it is not original to the Avanti.   But I also know that the person who had this car apart, was also parting out a couple of 289 Hawks around the same time.  I checked all my connections and they are all tight and clean.  I will fabricate the heat shield and do the amperage test next.

[landriopa]

Well, it has been a couple of interesting weeks.  I started with heat shielding the Delco starter, that did not help.  I them used DE exhaust pipe wrap back to the gear shirter, that did not help. I got a rebuilt starter Prestolite from Myers Studebaker. So now I got the correct starter and that did not help.  I did a test on the battery first when charged and after running it at highway speeds for 30 minutes and both times it shows 18.2 volts.  Then when cranking the voltage downs from 16 to 9 volts after about four revolutions and then the starter speed drops to a stop.   So I have the 3EE tested at two stores with the same result, instead of having 400 CCA, it has 299 CCA.  So I buy both a new Series 51 battery with 500 CCA rating and 1/0 cables they will get installed Wednesday. 

Even though I converted the voltage regulator to a electronic circuit, could it and/or the alternator be charging a problem with the battery due to overly high voltage?  Is 18+ just too high?  I did recently check the 3EE and all the cells had water over the plates and I topped each cell with more distilled water.  What else am I missing?

[Ron Dame]

18 V is way too high, it should be 14.5 or so

[Gunslinger]

As Ron said, 18V is way too high...you'll cook your battery.  14.5V is maximum and 13.8 is considered optimum charging voltage.  

[StudeNorm]

The mechanical regulators had some adjustment possible but I am not sure what you have for an electronic reg... I installed a Toyota 1 wire alternator when my old one died and I haven't had a problem in 4 years. Mechanical regulators are still available so if you are happy with your alternator you might replace the reg. It actually sounds like the electronic reg you have is not wired correctly which is why it simply sends an unregulated 18 volts onto the charge circuit.

[landriopa]

All good mysteries need an exciting ending.  The regulator issue was not primarily with the regulator.  Just because you have relied on your faithful battery charger for thirty years, that does not mean that someday it it will create a mystery on its way to the scrap yard.  Even after I insulation wrapped and then replaced the starter, insulated the exhaust pipes, checked all my connections I found that the battery was showing over 18 volts.  It had fried its plates.  A lot of voltage but no amperage.  So I replaced it and then checked the battery charger.  As a test I hooked it to a known good battery that was fully charged at 12.8 volts.  It charger immediately started raising its voltage past 13, then 14 towards 15.  The circuit that should lower its output had stopped working. 

I took this opportunity to also upgrade to a 55 amp alternator with integral voltage regulation.  The article explaining the suggested wiring changes was easily accomplished.  Plus I added a new series 51 battery which just need a fabricated new hold down and I am now smiling each time my Avanti starts up.  Thank you all for your advice and fact checking.