Hot starting problems.... on a 914/6 Options

[914_6conv]

Hi, new to the list but not to 914s. My problem is that whenever i try to restart the engine after a short stop, lets say a fuel fill-up, it just doesnt. It cranks, but does not fire. After a while, 5-10 minutes, it does. No problem on cold start, it fires right away. I suspect bad coil, misbehaves when hot. But once started, it runs fine. any clue? My set up: Blue coil, Permatune, Pressure regulator, webers on a 2.2E engine with S-cams. Thanks to all.

[dmilzoff]

I had same problem with mine. This is a common problem. Check or replace the ground wire between the engine and body. Check for rust or paint under the ground wire where it bolts to the body. To test, bring battery cables with you and, when you are having the problem, connect one end to the engine and one end to the body and try to start the engine.

[914werke]

CHT!? Oh this is a /6 ? (IMG:style_emoticons/default/blink.gif)

[Jeffs9146]

I had this problem a long time ago! It would only stop working after driving for longer than 30 minutes. I took the soleniod off of the starter, cleaned it and it worked for about a week. Replaced it and I never had the problem again.

Jeff

[Racer]

How old is your starter? You may have a bad ground, or need to replace the starter/solenoid. If you do need to replace, I recommend a "high torque" starter. Its a little stronger and more heat resistant...

[mskala]

I had this problem, was very confusing initially because if you played
around with ignition things, it would start working, but only because
time had let it cool down. The problem was the Permatune. (IMG:style_emoticons/default/icon8.gif)
I don't know how, but my failure mode was no spark when car
(permatune unit) was hot, after you shut it off. It didn't just die while
driving for some reason.

[si2t3m]

Bon, t'as finalement trouver le site!!! Bienvenue!

Ok so we ruled out the carbs and gas issues and it now seems to be electrical or something to do regarding the ignition.

Do you remember from where the permacrap is getting it's power? IIRC we connected it to the + that was used for the engine blower (fan that pushed air in the heat exchangers). I think a relay on the relay board is used for the engine blower. Could it be that the relay doesn't energize properly when it's hot?

As for the easy things, clean the ground stap and connection points if they are dirty. Check if you have spark when it doesn't want to start. Check the wiring going to the permacrap, if it uses a relay, just swap that relay with one coming from the headlights.

HTH

Marc-André

[rhodyguy]

he says it cranks hot or cold.occasionally my 4 with carbs starts a little ruf on a HOT day after restart and a short sit. could this be the fuel heating up in the lines and the carb bowls?

kevin

[ArtechnikA]

Ok so we ruled out the carbs and gas issues...

we did ? don't think i saw that .
could easily be fuel percolation. (of course i'd pitch the Permatune just on basic principles...)
make sure the insulating blocks are in place - i can never recall if they're between the heads and manifold, or manifold and carb base, but they need to be there, with gaskets in good shape.

the anti-percolation fuel bowl vent mod described in Anderson's book using the PMO drill fixture is also an excellent idea...

[Rusty]

I had this problem, was very confusing initially because if you played
around with ignition things, it would start working, but only because
time had let it cool down. The problem was the Permatune.   (IMG:style_emoticons/default/icon8.gif)
I don't know how, but my failure mode was no spark when car
(permatune unit) was hot, after you shut it off. It didn't just die while
driving for some reason.

Permatunes are never go bad. Just call the company (or Wayne) and ask them.

[si2t3m]

Sorry for the confusion, we rulled it out offline.

It was something as basic as:

Try to start it hot,
1. Without touching the pedal
2. crank and give it 1/4 pedal while cranking
3. pump a couple of times and crank
4. floor it and keep it floored while cranking

It didn't start be he smelled gas so what i wanted to say was that we are getting fuel & air. We don't know about spark when hot.

Just for the information, the insulator blocks go between the heads and the manifolds. The kit comes with the insulator blocks, gaskets and longer intake studs.

(IMG:style_emoticons/default/driving.gif)

Marc-André

[ArtechnikA]

It didn't start b[ut] he smelled gas so what i wanted to say was that we are getting fuel & air...

maybe too much gas...

in addition to percolating the gas out of the float bowls (of course they -should- refill from the pump right away unless there is a lot of vapor in the fuel lines...) the big problem is that all that float-bowl gas runs right down into the engine. could be you smell gas because fumes from the flooded cylinders are coming back through the open throttle butterflies...

anyway - it definitely could be ignition - i've had heat-sensitive CD boxes too - Permatune does -not- have the market cornered on this phenomonon ...

[rhodyguy]

(IMG:style_emoticons/default/blink.gif) .so you're stating it was/wasn't a fuel issue? floor the gas while cranking? pull a plug. must be interesting when things catch with that start up procedure. bet there's a wet plug/s.

kevin

[si2t3m]

AHAHA!!! It's not a startup procedure, it's was just something to test.

So it was basically richening out the mixture in each step:

Step 1: It should start this way
Step 2: Might not be enough fuel, let's give it some.
Step 3: Still might not be enough, let's give it more.
Step 4: Obviously flooded, let's try and lean it out.

When my engine is cold, like this morning i'll let the fuel pump prime the system and i'll floor it 2 or 3 times. This activates the accelerator pumps each time squirting extra gas in the cylinders. It usually catches on the first try. I'll then blip the throttle, each time injecting gas again from the accel pump to prevent it from stalling. After a couple of seconds, i'll get a steady rpm, but if i let go the pedal, the rpm's will climb down to around 100 so i keep the gas pedal pressed a bit. after around 10 seconds of this, the engine speed will pickup (without me changing anything with the gas pedal). At this point, i know i'm ready to take off.

When the engine is hot, i'll start it without touching the gas. On some occasion, while cranking, i'll give it 1/4 gas pedal if it's medium hot! (IMG:style_emoticons/default/wink.gif)

If one screws the procedure, and floods the engine what is there to do??? I was always tought (on a carbed engine) to floor the gas pedal. It will initially squirt extra fuel in the cylinders but once the accel pump is empty no more fuel is coming from it. The carb is now letting way more air that gas in the cylinder 'drying out' the combustion chamber. Eventually the air/fuel mixture will be ok, and it will start. It does take a while before it 'leans out' but it will do it.


Heck the flooring thing even works with FI! Passat had a bad coolant temp sensor so it was dumping extra fuel when hot (was thinking it was cold). The only way to start it was by flooring the pedal and keeping it there and start cranking.

Marc-André

[Rusty]

Marc Andre..

Jon Lowe has a couple of my Bosch CD Boxes. I'll email him, and see if he's done.

If so, you're welcome to use one to test your problem.

-Rusty

[si2t3m]

Thanks for the offer Rusty! (IMG:style_emoticons/default/beer.gif)

We might be able to get another CDbox in our area to rule his out.

Mine runs fine BTW. I'd even say that it's my daily driver! (We need a cloverleaf smilie!!!).

I've been (IMG:style_emoticons/default/smash.gif) on 914_6conv to get a MSD for over a year now and take the permacrap to the garbage can.

In a heartbeat i'd go for:
MSD, MSD high vibration coil & Magnecor wires.

Marc-André

[914_6conv]

Im the thread starter. Well guys, so much attention flattens me..... As i said, it only gives me trouvle when hot. On cold start, i take the sit3m approach: Let the pump fills the carbs, pump 3-4 times and crank. Fires right away. Never had a problem in more than a year. All lines/filters are new. This is why i dont suspect a fuel problem, also because once ignited, it runs fine with no shortage of any sort. I must add here that i once ignited it on compression and it started right away, but that was the first time i encountered the problem. So maybe the time i kicked the tires (sigh), it cooled down!

And strange thing that may lighten some, when diagnosing the problem, i once saw white smoke coming out off the first cylinder, between the manifolds and the carbs bodies!!!!! Any clue?

When hot, it cranks but do not ignite. So if i recap, check any of these:
1) check the ground battery cable and/or jump it with booster cable
2) replace permatune - always thought that they werent acting intermitently!
3) replace coil
4) check selonoid on starter. I dont get this one, if it cranks, the selonoid should be OK, right?

Thanks for helping!

[ArtechnikA]

In a heartbeat i'd go for:
MSD, MSD high vibration coil & Magnecor wires.

the exact setup i have on the 911, later tonight it'll have a genuine Bosch dizzy rotor and one less thing to worry about.

i need to tweak the idle mixture (runs very rich there) but the MSD is firing some very sooty plugs right now...

[ArtechnikA]

Im the thread starter. Well guys, so much attention flattens me.....

...So maybe the time i kicked the tires (sigh), it cooled down!

... i once saw white smoke coming out off the first cylinder, between the manifolds and the carbs bodies!

2) replace permatune - always thought that they werent acting intermitently!

my /6 isn't running, it gives me a vicarious sense of satisfaction if i can help someone else's ...

Permatune would have you believe there is no such thing as an intermittent failure, but they'd also have you believe there is no such thing as a Permatune failure, and both are patently false.

the steam/smoke is reinforcing my belief there's a fuel percolation issue; do you have the float bowl vent mod done ?

if the issue is percolation and too-rich mixture, multiple fat sparks from a MSD *might* help get the fire lit even if the Permatune is working to spec (hey, it could happen ...)

[si2t3m]

fuel percolation. Good point.

I have the insulators on mine, so it does take some time before the manifolds & carbs get hot once the engine is stopped. On mine after a long drive, if i immediatly touch the manifolds or carbs after i stop the car, they are not hot. It will take around 5 minutes before they get hot to touch. Don't know how it was without the insulators, but heck, I would be a good thing to check.

Are the intake manifolds & carbs freaking hot when it doesn't want to start?

Marc-André