hot start problem/ideas

[indigoth]

ok, so yesterday for the first time, my pinz left me stranded. the so called hot start problem. I got it started and home but only after draining the batteries multiple times. it's had the hot start problem before but it's always started after some time.

the three issues i've heard which contribute to the problem are
1) float level too high
2) float level too low
3) dirty/poor connection on coil - to - distributor wire.

any one have any more thoughts of what I can look for that could fix this problem?

and while I'm at it ... I've looked for the method for measuring the float level using a vernier caliper measuring from the top edge of the carb bowl, but i'll be darned if I can find it ... could someone steer me to it again or reiterate what the measurement should be?

thanks in advance

jim
'73 710m
'02 hyundai
'02 ducati monster
'81 fiat X1/9

[David Dunn]

Check your coil and ballast resistor. Overvoltage to the coil will cause them to overheat and make it next to impossible to restart hot. The coil should be warm, but not hot. If you let the truck sit for 15 minutes or so, it will usually cool enough for a easy restart.

Dave Dunn

[djb_rh]

Curious if anyone can elaborate on the "check your coil and ballast resistor" thing. How does one properly check them on this problem?

I bought Jake Raby's personal Pinz that he used to develop his fuel injection system on, and this "hot start problem" has just started on me. It's obviously not carb issues since I don't have a carb, but a fairly good mechanic friend suggested that it sounded like a coil issue.

So, how to best check this for sure?


--Donnie

[Erik712m]

Donnie,

Screen three on the controller will tell you the voltage level.


Erik

[pinztrek]

It's obviously not carb issues since I don't have a carb, but a fairly good mechanic friend suggested that it sounded like a coil issue.

EFI can have hot start issues as well if you get vapor lock due to heat soak of the fuel rails. It depends on how your fuel rail is setup, should be rare if you have proper bypass circulation back to the tank.

I'd still check coils & spark, but if they check out and you still have a problem it's be worth checking. Jake should be able to get you some pointers on how to confirm it's not fuel related.

Have fun,

Alan

[Erik712m]

Out of the manual.

Testing the coil pack for spark (4 cylinder) Caution high voltage!
Never test for spark by just removing the plug wires.
Clamp spare spark plugs together and plug in ignition wires to the coil under test. If you don’t have
spare spark plugs use some steel lock wire and wrap it around 1 coil terminal and run it over to the
other terminal leaving a small gap to be able to see the spark jump.
Connect the black wire to ground and the red wire to +12 volts.
Touch +12v momentarily to the input marked A on the black connector. There should be a spark from
the 1-4 coil. Move the spark plug wires to the 2-3 coil and momentarily apply +12 volts to the input
marked B on the black connector. There should be a spark from the 2-3 coil.

[djb_rh]

It's obviously not carb issues since I don't have a carb, but a fairly good mechanic friend suggested that it sounded like a coil issue.

EFI can have hot start issues as well if you get vapor lock due to heat soak of the fuel rails. It depends on how your fuel rail is setup, should be rare if you have proper bypass circulation back to the tank.

I'd still check coils & spark, but if they check out and you still have a problem it's be worth checking. Jake should be able to get you some pointers on how to confirm it's not fuel related.

Jake had been daily driving it for a while, so I'd think he'd have had this problem and fixed it if it were just a setup problem with the fuel rails, though. And he lives in Georgia, so I'm sure he had plenty of heat soak opportunities. But I'll check the other stuff and then if that doesn't pan out I'll be yelling at Jake. Loudly.


--Donnie

[chacaocop1]

Did you find out what the problem is Jim?

Remember if your truck doesn't start when hot, take the engine cover off, touch the coil with your hands and if it is hot, I will suggest to simply change the coil for a new one.

With that solution I will venture to say that you will have 80% chance of success.

The same issue happened to a Mustang I used to own, to my Pinz and to my 1956 beetle.

Let us know if you solved the problem or not.

[indigoth]

the coil appears to be cool to the touch when i turn it off. the ballast resister is on the warm-close-to-hot side, but still "cool" enough to touch and hold without burning my hand. it'll restart immediately-after-it's-hot with no trouble at all. after about 20 minutes of sitting and cooling off, it's a "no-go" tho ... which is troublesome when i want to make a run to the store. I lowered the float level in the carbs to the point it was clear it was running lean and then raised it till it ran well. It used to have a general gas smell as tho it was running rich ... that smell is gone now. it runs well and starts hot marginally better, but no where near like i think it should.

there is some heat soak going on, so it could be the coil. i still have the military coil, dist cap, plugs on it but the petronas electronic ignition kit was installed by the previous owner.

[pinztrek]

there is some heat soak going on, so it could be the coil. i still have the military coil, dist cap, plugs on it but the petronas electronic ignition kit was installed by the previous owner.

You know the old saying: "99% of fuel problems are ignition related"......

I'd be ready to do the following in failure mode:

- Check spark from the coil to the distributor
- Check spark on a plug
- Ohm the coil, also check voltage at the coil

Back in the fuel space:
- Check the carb throats for accel pump squirt.... if you are getting a real heat soak it can evaporate the fuel from the bowl, etc

Pre-EFI & distributorless ignition I replaced my military coil with the electically identical "Bosch blue coil". There are a couple of variants, one is an exact electrical match for the pinz. My military coil was marginal, OK at higher voltages/revs. I was able to swap and keep the mil dist cap using the civilian wire trick.

The bosch blue coil swap was a 15 minute test, and it ran so much better I stopped chasing EFI for a while.

Have fun,

Alan

[indigoth]

- Check spark from the coil to the distributor
- Check spark on a plug
- Ohm the coil, also check voltage at the coil

these were next on my list of "to do"s

- Check the carb throats for accel pump squirt.... if you are getting a real heat soak it can evaporate the fuel from the bowl, etc

seems to squirt ok, but i'll double check

... "bosch blue coil". There are a couple of variants, one is an exact electrical match for the pinz. My military coil was marginal, OK at higher voltages/revs. I was able to swap and keep the mil dist cap using the civilian wire trick

I want very much to do this ... but ...


what's the "civilian wire trick"?

thanks tons ...

jim

[pinztrek]

what's the "civilian wire trick"?

Marine heat shrink with adhesive
Straight or angled boots & crimps from NAPA
8mm silicon ignition wire

In your case you'll need to cut open your military coil to dist cap wire. You'll want to disassemble the cap end.

Then using the heatshrink and instructions somewhere still on the web, you adapt the military connector (for the dist cap) to the 8mm civilian wire. For the coil end you use a normal boot.

You'll have to put spade terminals on the coil hot & points wires as well. But before you do the mod, you may want to check the existing coil hot & points connectors. If I recall, they get grungy and could cause low spark by themselves.

If you do the blue coil mod, find a "raincoat" from a BMW in the junkyard to weatherproof it. Photo's on my website:
http://pinztrek.com/pinz/mods/pinz_mods.htm


You can also see how I snaked the pertronix wire out the shielded wires.

Also, read the archives as I've posted in the past how to measure & find the blue coil which is the exact match. One which is labeled 3 ohm is not, it's actually 9 or so. My local bug/914 shop had them in stock, knew how to tell the difference, and was a great help.

The civilian wire trick with pertronix worked great on mine. I never had to replace my cap, and being able to use good plugs really helped. If you do it, use resistor wires, but not resistor plugs. Most of the platinum plugs are resistor now, so the basic VW non-resistor low-tech NGK or Bosch plug works best.

When you convert to EFI/distributorless, you can use resisitor wires & plugs due to higher voltage. But I still use the basic ones.

Have fun,

Alan

[indigoth]

ah

i suspected as much.

I contemplated doing exactly this but was afraid of cutting up the military wires. I'll do it this weekend.

and thanks again.

I suspect this'll fix my troubles.

jim

[indigoth]

put a new coil on ... actually, not just the coil. sprang for the civi conversion ... and it passed the first test. run to temp, turn it off and restart after approx 20 minutes. starts just fine now, just like it should. the old military plugs came out pretty black, tho. I think it's still running rich.

thanks to everyone for your input.

jim

[M Wehrman]

Very possible black plugs from poor spark.
Mark