Engine starting technique

The 512 M manual reccomends towing the car in fifth gear for 5 minutes before starting to get the oil flowing. (True)

 

Ray, agree absolutely with Yale. In normal driving the main fuel pump provides ample fuel most of the time, but if you stop or are moving slowly and the revs drop, the under bonnet heat can be enough to cause vaporisation and insufficient fuel gets through.

In very hot weather, I occassionally find that the first sign is a cylinder or 2 dropping off at low revs and this is quickly cured by switching on the auxilliary pump.

Interested that some of you guys use the choke in places that are quite a bit warmer than the UK. Most people seem to prefer 2 or 3 pumps on the throttle and I doubt that this gets the opportunity to wash the bores before the engine fires - much worse to run with the choke out for too long!

John

 

I agree that running with the choke on too long would be bad. But the driver would be alerted to the fact by the irregular idle and sluggish acceleration he would notice.

I agree that 2 or 3 pumps of the throttle is OK. But if you're having trouble starting keep in mind that 10 or 12 pumps may not be the best way of getting the engine going.

When I got my car it had the Stratos induction system with 40 IDF's and only one OEM fuel pump. We put the car on a chassis dyno and found that the car was going lean at high revs and load due to loss of fuel pressure, and the dyno owner said we needed more fuel flow. I switched to a Holley pump capable of feeding a big V8 and it solved the problem.

Just something you may want to keep in mind if you're driving your car hard with only one pump running.

 

I own a 72 246 GT. Daily driver. 185,000 miles so far.

Switch on and wait for fuel pump to slow down (about 15 seconds.)
Cold, starts right up. Half throttle is enough.
Hot, throttle to the floor and crank until it fires.
I never use choke, cable has been disconnected for 19 yrs.
I use NGK Iridium small dia. center electrode plugs only.

Champion, AC, etc. standard plugs will not fire on cold wet mornings.
I live in Santa Barbara, 40 is cold, 90 is hot. Humidity is generally 10 to 40%.
Makes life easy!

Same technique has worked in Las Vegas in the summer, and snowy mountains of Southern California in the winter.

Plugs are critical in morning, full throttle is critical the rest of the time. Starts right up unless something is really wrong.

Luck,

John

 

Which heat range?
Equivalents to the BP7ES that I've been using?

 

NGK BPR7EIX Iridium have been in car for last 5000 miles. NGK BP7EV Platinum were in car for more than 40,000 miles when I decided to change them just for the Hell of it. They still ran fine and looked good. Conventional plugs used to start hard after 3000 miles. Pain.

Turns out that NGK Platinum had become obsolete. Iridium was in. No one in Santa Barbara had such a critter. Did try Autolite Platinum just because local NAPA had them. Not as good as old NGK. Center electrode much larger and that may be the reason.

Ordered the NGK plugs from LA. Got them the next day. About $7.50 each. So far no problem so Iridium is at least as good as Platinum. Way to go!

John

 

1. I had this problem with my 365 GTC4. Never was able to fix it until I had the starter motor rebuilt. Now it starts easily cold or warm. Never need / use the choke.

2. Had an interesting discussion once with a very seasoned Ferrari mechanic, esp on older cars. His experience on hard starting in late 60s and early 70s Ferraris was that the relay between the ignition switch and the starter solenoid was poorly designed and delivered only moderately sufficient amps when cold to spin the starter motor. Once the relay and starter heat up under engine running conditions, the resistance goes up, and the current really struggles to spin the starter. His solution: wire a push button directly to the solenoid and bypass the ignition switch and relay.

 

Jim G,

A 512 M is modern by your standards. I don't think you should mess with them new fangled starting techniques.

If I recall some old airplanes used cartridge starters, a large cartridge (think 50 caliber or bigger) without the bullet was fired to get the engine spinning.

Art S.

 

This thread reminded me of a story I once read on here (maybe the old board - couldn't find it when I searched) that told of a lady with a 365 GTC4. As I remember it, her mechanic told her to slowly push the gas pedal to the floor three times when starting.

Apparently she misunderstood and did this AFTER starting. Every morning she would wake the neighbors by revving up her cold engine to 10k three times until one day her clutch disintegrated.

Does anyone else remember this story or know how to find it?

Regards,

Art S.

 

how 'bout this? [this is real..you couldn't make this up]....starting cold.
1. drain the oil...heat it to 90-100 degrees
2. refill the engine one quart at a time to 7.5 total [no dipstick]
3. pull all 8 plugs.
4. turn engine by hand crank at least 10 turns
5. hit starter button till oil pressure guage registers movement.
6. replace plugs.
7. turn hand air pump valve to pressure setting. pump fuel tank to 2-3 lbs.
8.open fuel line valve to open.
9.turn supercharger oil drip line to on.
10.retard spark lever.
11. turn magneto switch to "on".
12. open petcock on intake manifold and add fill cup with fuel..close when drained
13. depress throttle 1/2 of full travel...hold for 30 sec;[allows blower oil valves to stay open to drain into bearings.]
14. hit starter button till engine fires.
15.advance spark lever.
15. hold 1200 rpm for 30-sec to 1 minute. return slowly to idle.move off quickly so not to foul plugs.


differs a bit when warm..but not much.
[any guesses as to car??]

 

Does it have roller bearings and a 1-6-2-7-3-8-4-5 firing order?

 

It's either a Lotus or a Duesenburg....Actually sounds like an old F 1 car.

Ken

 

Blower Bentley???

 

Bugatti Type 35B

 

BBs were 4 cylinder cars.

 

1,5,2,6,3,7,4,8.....oui!

 

Quick question .. Do you find u have to keep revs above 2000k when cold for a few minutes before it will idle without the choke? (actually dosnt even idle with the choke when stone cold) .. Car is a 250 Lusso ... thx guys