18RG Starting troubles

[RAd28]

Hey guys,

Been having problems lately getting the 18RG started when it's cold. Problem has only arisen since i installed an electronic dizzy, and started almost immediately after doing so. It's really difficult to describe the problem in writing, but it's as though it turns over less then 1 full rev and the startermotor just can't find the power to keep turning it, if you hold the key in the start position it'll eventually crank over another rev, and i'm sure it'd eventually spin fast enough to start. what i've been doing however is just holding the key on long enough to get one (part) rev, and pump the throttle until it starts, which is typically 2nd or 3rd go, once it's warm though it starts fine... I've absolutely NO idea what's causing this, the starter motor is relatively fresh, as in it's an exchange unit less then 3-4yrs old.

anyone got any reasonable suggestions?

[Lambolica]

Check the power teminals at the battery for corrosion and the same at the starter motor.

Cheers
Simon

[river]

Hi,

Battery? Though I'd figure it would die before turning over the engine a few times, albeit slowly.

Check the main voltage cable that goes to the starter. Does it get hot? If so there is resistance in the cable and you should disconnect the cable and clean up the connection points and reconnect it.

While you are at it, check the earth straps to the engine (I think they connect to the block) and give these the same treatment.

I can't see how the new dizzy would cause this problem.

seeyuzz
river

[thechuckster]

ignition key switch is probably in need of a service - remove, take apart and remove any corrosion/pitting, re-assemble with a very.small amount of grease.

while you'r stuffing around under the dash, wire up a relay to provide power to the starter solenoid so you only switch low current levels (e.g. a relay) with the key switch.

[RAd28]

Lambo - Yeah... Come to think of it, battery terminals are pretty corroded... just been to slack to clean it up.. will get to that tomorrow.... (said that plenty of times already, I know..)

River - Battery is fine so far as I can tell, I've been having these starting problems for the best part of 6 months now, and it hasn't got any worse, acctually it's gotten better, but i put that down to the temperature... Will have to do a thorough check over all the straps and cables etc for corrosion, and fraying etc. Also, I don't know if the dizzy is the problem, I suspect it's something I've done when installing it, i.e. bumping something, leaving something disconnected, or just something along those lines...

Chuckster - I'll get to that after I've done the above...

[sleeektoy]

I had an auto sparky fix this same issue so i'm not 100% sure

I think theres a thin wire that runs from the coil to the starter on some cars that doesn't seem to work when u fit the electronic dizzy/coil. It provides a "boost" to the starter on cold starts.

[airfireman1]

No so. the starter has a feed direct from the battery. what you are talking about is the wire that gives the coil 12 volts whilst cranking and then goes thru the ballast resistor on the coil when running to give 9 volts to the coil. Helps with starting and helps keep the coil cool when the engine is running. I have had no problems retro fitting an electronic dizzy to the 18rg. Battery terminals, and bad contacts in the starter solenoid are the main areas to look at.
Cheers Dave

[river]

Hi,

Agreed. It seems, from the description, the starter is cranking slowly and not an issue with the actual running of the engine.

seeyuzz
river

[RAd28]

haven't had a chance to play yet, but if it is bad connections etc, how come it works fine when it's warmed up a bit? it must be a VERY close call between good connection and bad connection to be temperature dependant... and if that was the case, then surely it would vibrate more loose, or more tight from time to time?

Will have a looksie later this arvo, and get back to you.

[river]

Hi,

You haven't got oil that's as thick as molasses in the engine, do you?

seeyuzz
river

[RAd28]

no... i have molasses as thick as oil...

[airfireman1]

Just out of curiosity have you had the battery load tested. Could be dropping charge. slow to turn over when the engine is cold due to low battery voltage. Turns over quicker on a hot engine because the battery has been recharged whilst the engine was running.
The battery may just be getting a 'surface charge" and not holding it very well.
cheers Dave

[river]

Hi,

To test that theory, turn your headlights on when the engine is cold and see how they look. If they are not bright or go feeble quickly then it is an electrical system (ie connections, battery, etc) problem and not the starter.

seeyuzz
river

[crowncustom]

Just out of curiosity check your valve clearances.Reason I say this is cause I had a couple of RG's many years ago and it would wind over but wouldn't start when cold but once going and warmed up it was fine.Cause was that the valve clearances where out of whack leaving the inlet valves open longer than needed causing it to flood itself.
This also happens out of the blue as well.
Cheers Brett.

[RAd28]

Had a look yesterday evening, and cleaned up the terminals on the battery, the starter cable though appears pretty buggered at the starter end, the insulation has melted off for a good 5-10cm, but i remember seeing that months ago and though "I'll ahve to do something about that"... so gonna rummage through the shed for another cable.

Airfireman 1 - I understand what your saying there, but when i say the engine is cold/warm, that's not literally refering to oil temp, when the ambiant temp is closer getting up there, around midday it's typically easy to start, but early morning in winter it was a real bastard...

River - Headlights are dimmer at idle, but if you pick the revs up to 1500ish and they brighten up.

Crowncustom - checked the clearances a while back, and they were pretty average, got new cams coming so will fix that up, Problem is that it's not winding over, starts easily though once it turns over once or twice...

[RA35GT]

Had a look yesterday evening, and cleaned up the terminals on the battery, the starter cable though appears pretty buggered at the starter end, the insulation has melted off for a good 5-10cm, but i remember seeing that months ago and though "I'll ahve to do something about that"... so gonna rummage through the shed for another cable.

Airfireman 1 - I understand what your saying there, but when i say the engine is cold/warm, that's not literally refering to oil temp, when the ambiant temp is closer getting up there, around midday it's typically easy to start, but early morning in winter it was a real bastard...

River - Headlights are dimmer at idle, but if you pick the revs up to 1500ish and they brighten up.

Crowncustom - checked the clearances a while back, and they were pretty average, got new cams coming so will fix that up, Problem is that it's not winding over, starts easily though once it turns over once or twice...

This part makes it sound like dieing battery. How old is it?

[Cruiser97_80]

Have you checked your ignition timing?

Incorrect ignition timing can also cause this sympton

[RAd28]

7M-GTE MX73 - As mentioned earlier, the problem has been occuring consistantly for atleast 6 months, I can only assume a dieing battery wouldn't last this long...

Cruiser - No, to be honest it hasn't crossed my mind, but i'll be sure to put the timing light on it on the weekend, thanks for the tip...

[GT1978]

Have you checked your ignition timing?

Incorrect ignition timing can also cause this sympton

As cruiser stated check your ignition timing. And the vacuum advance. Too much advance at slow engine rotation can make the engine work against itself.

Try cranking with 1/4 throttle to reduce vacuum seen by distributor and reduce advance at start up.

Glen

[thechuckster]

"early morning in winter it was a real bastard..." = poor charging from alternator combined poor battery condition = auto sparky charges you a small fortune for parts and labour

This could also be easily induced by poor/corroded connections and your battery is simply in a state of constant 'under-charged-ness' (Charles's new word for the day).

So before spending any money - simply remove the various high current connections (battery terminals, chassis earth, starter B+, engine earth, Alt B+) to clean each contacting face then re-attach/re-connect with suitable tightness. Replace anything that is badly borked.

My experience is that most electrical problems are mechanical in nature and thus able to be fixed by an owner with a rudimentary level of skill (e.g. knows which end of hammer to hold).