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Posted by: Ian Stott Jul 1 2017, 05:18 AM

As described! What is up with this situation? Engine runs beautiful when warmed up, will restart no problem if It has been shut off for even a few hours. Kudos to the battery and starter as I have tried to start it normally when it has been sitting for a few days, won't catch, thank goodness I live on a hill, coast down the hill a bit, put her in 3rd gear pop the clutch and vrooom! Have done this 6 times now!

Ian Stott
Moncton
Canada

Posted by: wndsrfr Jul 1 2017, 07:10 AM

I'm guessing too much voltage dip when cranking cold engine....look for corrosion on battery connections & ground strap at top rear of transmission...clean & tighten all of them....age of battery?

Posted by: Mark Henry Jul 1 2017, 07:27 AM

So is this the opposite of the hot start issue? Starter works but not firing cold?

Posted by: Ian Stott Jul 1 2017, 07:54 AM

Battery is awesome, starter works great, I can crank her over til the battery dies which I don't do! I always try to start it normally, so instead of burning out the starter or draining the battery too much I coast down the hill, put her in 3rd, polo the clutch and vroom! Then I let her warm up, charging system works great by the way, and once she is warmed up easy to restart with a simple turn of the key. Engine runs real nice when warm, so thanks for the choice of battery you chose for me Mark and I am happy with the job you did on my engine. This starting thing has me and my friend who is a mechanic puzzled, any ideas from you will be most helpful.

Ian

Posted by: draperjojo Jul 1 2017, 07:54 AM

I used to have to do this with an Opel GT. I rebuilt the engine after I did a wet and dry compression test. The pistons all fell out...lol. Hopefully your engine is in better shape than that one was.

Posted by: Krieger Jul 1 2017, 08:17 AM

Is this carbed or injected. If it is injected, I was thinking the cold start valve was not putting fuel in the plenum.

Posted by: Mark Henry Jul 1 2017, 08:20 AM

I wonder if the pertronix is crapping out. Check and clean all dizzy connections, ground straps, etc.
I'll have to think on this.

The Battery is a odyssey 925.

Posted by: Ian Stott Jul 1 2017, 08:34 AM

Batt connections and nice and clean and shiny! My understanding of petronix is you have nothing if it fails, since the engine runs so nice when warmed up and starts with one turn of the key after being warmed up. I did the PCA Acadia region valley tour a couple of weekends ago which was 720 miles, engine performed well, restarted easily after being off for about an hour while we had lunch, which was awesome, best fish and chips I have ever had which is saying a lot for a guy from Atlantic Canada. That is why I didn't suspect the pertronix which has been in the car for about 3 years or more. Ground strap is new, was done after the tranny clinic at your shop, I will check it though.

Ian

Posted by: ndfrigi Jul 1 2017, 08:46 AM

If this is F.I., try to push/pump the gas pedal 3 times then push it all down to floor and try starting it. If it start, maybe your cold start valve and CHT sensor need attention.

Posted by: Ian Stott Jul 1 2017, 10:07 AM

Will try that thanks.

Ian

Posted by: Mark Henry Jul 1 2017, 10:42 AM

An FYI to others, Ian has a 2.0 L-jet conversion.

Posted by: Mark Henry Jul 1 2017, 11:05 AM

Bit more info to help Ian out.

We (and another guru) couldn't get the D-jet to run worth a shit.
I traded him straight up for my known good complete 1.8 914 L-jet system. So his system is all L-jet except for the 2.0 intake runners, all new seals.
Ran perfect except for a minor point, in my 1.8 I never had to touch the gas to start the car, on his you always needed to give it one or two pumps, hot or cold.
I just figured it was the cam. IIRC he has a web73 FI cam.

O2 WB said the AFR was perfect as was the timing. Except for the two pump start it runs like a champ.

Ian a new head temp sensor might help. The one I used, off the L-jet, is 8-9 years old but only had about a year of use.

Posted by: Mueller Jul 1 2017, 11:11 AM

Is the flapper moving when trying to cold start? Not enough manifold vacuum due to leak or someone stiffened the spring too much?

Posted by: Mark Henry Jul 1 2017, 12:31 PM

I was careful about vac leaks unless it's a new issue,
Spring in the flapper?
I don't think so, off a bone stock 914 that lived a very sheltered life. I think it was driven for 4-5 years then spent decades in dry heated storage till I got it in early 2000's, then again always in dry heated storage.
Except for a re-spray it was a bone stock original cream puff.

Posted by: Ian Stott Jul 1 2017, 07:54 PM

Once warmed up runs nice, idle is bang on at around 1100.

Ian

Posted by: Ian Stott Jul 3 2017, 06:25 PM

Ok, coasted down the hill at my house, put her in 3rd gear, popped the clutch, vroom! Ran a little rough til warmed up, then ran beautiful all day, did a 300 plus mile tour thru some really nice twisty's, I can pull away from a 944' but the Audi TT can stay with me as she is a good driver, the Honda 2000, can stay with us in the straits but I easily loose them in the switchbacks. Not bragging, just trying to get some feedback on this cold starting thing, we stopped for lunch, we stopped for photo sessions, we stopped for coffee, teener started no problem every time. When I go to use it again, say next weekend for example, I know I will have to coast down the hill and pop the clutch again, but it won't start normally by turning the key. Battery and starter are both in excellent condition, can turn her over like crazy but no go.

Ian Stott
Frustrated in Moncton
Canada

Posted by: cuddyk Jul 3 2017, 06:55 PM

How long does it take to turn over when going down the hill? Right away?

Since it starts on a hill when cold but not using a starter when cold, there must be something about the momentum of the downhill that's making a difference. Correct me if I'm wrong, but it seems the force of the car rolling downhill in gear is doing a much stronger job of turning over the engine than a starter.

The L-jet gurus will chime in I'm sure, but it sounds to me like your FI brain somehow needs a very strong vacuum/signal to send fuel when cold. After warm up, whatever is sticking gets unstuck.

Posted by: type2man Jul 3 2017, 07:08 PM

How about spraying some fuel into the intake when cold

Posted by: r_towle Jul 3 2017, 07:25 PM

Vacuum leak

Posted by: Spoke Jul 3 2017, 09:03 PM

So it doesn't start when cold but will start if you push/coast start it?

What are the differences in both methods?

Engine speed:
Starter: slow
Coast: slow

Ok, so engine speed should not be the issue.

Extra fuel when cranking:
Starter: YES, the ECU extends the injector pulses to put in more fuel when cranking.
Coast: NO, the ECU sets injector pulse width by temp of engine/ambient/CHT

Here's a difference, pulse width during cranking may be flooding the engine. Maybe not. Does the engine run rich? Have you had the AFR checked?

Voltage at coil:
Starter: Voltage at coil will be lowered by IR drops in the wiring applying less voltage at the coil.
Coast: Voltage should be close to battery voltage since starter is not cranking.

Check the voltage at the coil with a voltmeter when cranking. Measure from coil + wire to engine case ground, not the battery ground. Also, pull a plug wire and install a spare plug on the wire and ground the plug and look for spark when cranking.

Posted by: Dave_Darling Jul 3 2017, 09:09 PM

How's the ignition switch? There have been some odd failures with some of them...

--DD

Posted by: Rand Jul 3 2017, 09:57 PM

Is it an issue of cranking over? If it turns at normal speed when cranking with the starter, it doesn't make sense that bump starting would be more effective. We are missing something. If it's not cranking quickly, we are missing the issue here.

Posted by: arne Jul 3 2017, 10:05 PM

I too wonder about the ignition switch. Hook up a timing light and see if the strobe lights when cranking. Maybe you have no spark when the key is turned all the way to Start, but poweres the coil in Run. That could explain it.

Posted by: falcor75 Jul 4 2017, 02:30 AM

Whats the voltage drop on the battery while cranking?
Can the ECU or coil not get enough energy due to the voltagedrop from cranking? Try putting a charger on the battery and keep it on while trying to start with a cold engine?

Posted by: Mark Henry Jul 4 2017, 01:13 PM

Doubt if it's the battery itself, one year old odyssey 925.
IIRC new blue coil, or did I use the stock coil from my L-jet system? I do know I used the dizzy from my old L-jet

You'll need a helper but try taking a voltage reading on the coil + wire when you start to crank cold.
At least that should show if your volts drop when cranking.

Vac leaks are always a possibility on an L-jet, even though I used new hose, replaced both cap seals, etc....

Posted by: Ian Stott Jul 4 2017, 03:14 PM

Sometimes it almost catches, but rather than run down the battery or burn out the starter I just coast down the hill, turn the key to on and pop the clutch in 3rd. Works every time, once warmed up restarts are no issue, vroom, every time. I am thinking along the same lines as you Mark that the device sending temp info to the ecu may not be working outside of a certain temperature range. I posted the above driving experience with the other cars as an indicator of how nice the engine is when warmed up, not to brag.

Posted by: Rand Jul 4 2017, 06:25 PM

It's not rocket science then. Swap out the battery and see how it works. If it bump starts, it's not a difficult mystery.

Posted by: r_towle Jul 4 2017, 07:50 PM

Vacuum leaks prevent ljet from starting.
The head to manifold seal is affected by heat.

Posted by: Spoke Jul 5 2017, 08:31 PM

Have this test been done yet?

That you can sit and crank the engine and it doesn't start, then push/coast start it I think shows it's an electrical problem and not an issue of vacuum leak or other engine issue. As others have said, perhaps it's the ignition switch.

Posted by: Ian Stott Jul 9 2017, 11:36 AM

Turned the key to the on position, gave 3 good pumps on the accelerator, half throttle position then tried to start the car, she started! A little rough til warmed up but once warm she runs beautiful, I can live with this!

Ian Stott
Moncton
Canada

Posted by: ndfrigi Jul 9 2017, 11:43 AM

My 75 1.8 FI has been like this! When it warmed up, everything is good except a little rough or low idle at first but when I drove it for a mile or 2. Idle will drop to around 850 rpm.