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Location:
brisbane
Registered:
March 2003
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ignition problems
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Fri, 30 May 2003 10:48
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hey,
ok when i rev my engine hard to around 5-6 grand it tharts missfireing real bad.. then after i do it it starts missfireing all through the rev range... then most of the time after i turn the engine off it dont start up asgain... it gets no power from the coil for a while then eventually kills the coil whatever the problem is.. i am on my third coil because of this and am wanting to know why it is doing this. thank you
i have an 18rg with points ignition. and it sonly started doing it when i put my 18rg in from the 18rc
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Location:
Puckapunyal
Registered:
April 2003
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Re: ignition problems
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Fri, 30 May 2003 11:36
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Sounds likely to be a short somewhere, are your points burnt out after all these coils also? Have a look at your spark plugs also and see if they are burnt/damaged.
So you upgraded to an 18RG from an 18RC recently right? (sorry, confused by last line) Check for any hanging wires in the engine bay, maybe some earthing wires - I dunno... there's usually a device across the ignition coil (white, long) but I forget what it is, check that it isnt cracked or broken (usually have to unscrew it from it's mount to check it).
Is the 18RG out of a trusted vehicle (one you had in another car) or did you just purchase it?
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Registered:
May 2002
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Re: ignition problems
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Fri, 30 May 2003 12:00
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hav eu resolved this yet ?
im having trouble starting my car too
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Location:
brisbane
Registered:
March 2003
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Re: ignition problems
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Sat, 31 May 2003 02:04
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i bought it as engine only.. i had to make the dizzy wire longer to reach.. its got brand new plugs ,points and new leads in it.. the littlwe barrel thing yo mean? i have a condencer on the dizzy and one for the coil.. do you think it maybe a condencer... the speedo doesnt jump so i dont think it would be the condencer on the dizzy.. or could it.. it has really got me baffled what it is... it always runs ruff when you drive it and flatspots after it starts having this problem. that device you are talkign about is the foamy thing? the resister.. that is ok.
you think it might be cause the timing might be jumping all the time from having the vecumn advance on one cylinder or is that normal for the 18rg/s i am not surei just got that thought in my head today.. you can see the vacumn advance knob moving in and out qwuickly do you think that might be the cause of the coil dieing al the time?
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Location:
Rocky Mountains, Canada
Registered:
May 2002
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Re: ignition problems
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Sat, 31 May 2003 05:15
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Does the coil get very very hot?
Does it start leaking oil?
If so, then its probably because you have wried the ballast resisitor incorectly (its not foam, its ceramic).
While starting the engine, the ballast resistor shouldnt be used (coil gets 12V), but during normal running the resistor is used meaning the coils gets ~6V.
Having the coil running on 12V all the time will make it get hot, leak oil and burn out.
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Location:
brisbane
Registered:
March 2003
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Re: ignition problems
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Sat, 31 May 2003 07:34
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i have got rid of some of the problems ... the vacumn advance on the dizzy was only hooked up to one cylinder (not sure if its meant to be like that on the 18rg's) i d/c'd that and brought the timing up and it seems to be running alot better now but still not sure about the burning out of coils.. i guess the next few days will tell...
the resister is wired up the right way. the wire isnt broken(if it was broken it'd only run when you are on start and not on)
so will see what happends after i have taken the vacumn advance off... cause it was retarding alot on 3 cylinders and advancing on only 1st cylinder.. it idles alot better and runs alot smoother as well. and has a bit more power. but yeah will see how the coil go's int he next few days.
les you might be having starting problems because of the timing like what i just said but then again it is just a guess.
M.W.B that makes sence.. so if the coil burns out you think it might be the resister?
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Location:
brisbane
Registered:
March 2003
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Location:
Sydney
Registered:
April 2003
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Re: ignition problems
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Sun, 08 June 2003 10:55
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If the resistor is getting hot and the coil isn't, there may be a mismatch between the coil primary resistance and the ballast resistor. Measure them both with a multimeter, then check the results against the manual if possible.
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Location:
brisbane
Registered:
March 2003
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Re: ignition problems
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Sun, 08 June 2003 10:59
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the resister is 6.5 ohm with a gt40 coil aparently suited for 18rg
i was thinking it might be a dizzy problem that might eb making it run like it does when i give it some.. any thoughts?
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Location:
Sydney
Registered:
April 2003
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Re: ignition problems
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Sun, 08 June 2003 11:45
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6.5 ohms? It should be about 2 ohms I would have thought. The ballast resistor is designed to reduce the static current of the coil to about 5 amps (from memory). Most coils I've measured are between 0.5 & 1.2 ohms. I think your problem may be just lack of primary current which is affecting the coil saturation at high revs. Measure your coil's primary resistance and then get a ballast that would give you a static 5A then go from there. If this much current burns your points then change to electonic ignition that triggers from your points.
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Location:
brisbane
Registered:
March 2003
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Re: ignition problems
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Sun, 08 June 2003 11:51
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it says 6.5 ohms on the resister anyway.. yeah i wil eb going electronic soon it was doing this problem with the old coil and resister as well its really got me fucked
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Location:
brisbane
Registered:
March 2003
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Re: ignition problems
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Sun, 08 June 2003 11:53
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do you think it might be a wireing problem.. i used the same coil and resister with the old ones witht he 18rc and had no problem.. went to 18rg and since then it has always had a problem..
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: ignition problems
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Sun, 08 June 2003 11:55
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if you still have points, get a jaycar HEI kit, ditch the GT40 and get a stock replacement oil filled coil, or an electronic ignition coil from something cheap like a commodore, and you should have no more ignition problems.
the jaycar HEi kit uses the points for signal, so it doesn't really matter if they flutter... and the poitns last for years...
i have this setup in my rolla and it revs to over 9k and has no ignition problems.. and the sparks are at least an inch long....
the GT40 coils die when using the HEI kit and i would not recommend to anyone to use a bosch GT40 coil.... i have had nothing bu tproblems with them. i think a stock cil will always be better than them...
Cya, Stewart
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Location:
brisbane
Registered:
March 2003
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Re: ignition problems
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Sun, 08 June 2003 12:09
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i ahve got the stock electronic dizzy for the 18rg i just godda get a few things to make it run hopefully my problems wil be over ocne that is fitted up.. reckon a 22r coil wil be fine or even the gt40 for that?
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: ignition problems
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Sun, 08 June 2003 12:09
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oh, what plugs are you using? are they the right heat range? what timing is it set at? how much mech advance etc...
does your mechanical advance work? if it is locked, the lack of advance will make it crap at higher rpm... but may not explain the coil dying.. altho if it's a GT40 they do that 
also what is you plug gap? with stocko stuff, 0.8mm is good, but with HEI, maybe 1.0mm?
is the ballast resistor in circuit and it is not being switche dout the wrong way (ie in at start?) what voltage do you get across the coil? what voltage is there when you rev it ti higher rpm? what is it when the engine is off and key is at start and ign?
just a few ideas...
Cya, Stewart
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Location:
Sydney
Registered:
April 2003
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Re: ignition problems
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Sun, 08 June 2003 12:13
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Points have only a 50% duty cycle they are off half the time.
Now if you have a coil which is as little as 0.5 ohms, then the total resistance is 7 ohms which equates to 2 amps of primary current. So you have 2A or less for half the time. If your running a high compression or have a spark gap bigger than 0.8mm, your going to have trouble as revs rise.
With electronic you'll have 5A primary current and saturation time which is the time between sparks minus 1ms, so a much higher chance of coil saturation at high revs. At 7000rpm you should have 4ms between sparks, minus 1ms gives 3ms saturation time. With points you'll have 2ms saturation time (50% duty cycle).
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Location:
brisbane
Registered:
March 2003
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Re: ignition problems
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Sun, 08 June 2003 12:13
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lol umm i dunno the plugs that 18rg's use? they aint the same as the 18rc oens though ummm it isnt the gt40 thats making it run shit it was doing it bfor it ehe... it dont sound liek its getting enuff spark.. then after not taking it past 3k it goes to normal again untill i take it past 3.5k it is weird
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Location:
brisbane
Registered:
March 2003
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Re: ignition problems
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Sun, 08 June 2003 12:15
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so you think it might be a spark plug problem in the 18rg.. only been doing it since 18rg went in
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: ignition problems
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Sun, 08 June 2003 12:27
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it could be, if the plugs are not getting enough juice or the gap is too large, the spark could be being blown out..
could also happen if the plugs are the wrong heat range... pull em out and have a look, close them up to 0.8mm, also check the points gap to make sure it actually has some dwell (the longer they close, the longer the dwell)
the jaycar HEI kit has a fixed 1ms spark and is charging the rest of the time...
Cya, Stewart
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Location:
brisbane
Registered:
March 2003
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Re: ignition problems
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Sun, 08 June 2003 22:54
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ok kewl thanx will have a ood look today thanx for ya help mate 
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Location:
Brisbane
Registered:
December 2002
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Re: ignition problems
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Mon, 09 June 2003 00:40
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you said you have the electronic dizzy, just go and get a coil from and old 5me. these have the ballist rsistor on them too. works fine in my 18rgeu. and wires up just about the same too. the only differance is the 2 wires that come fron the dizzy that do to the ignitor. One red one white. colours are usually the same on most old toyotas
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Location:
brisbane
Registered:
March 2003
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Re: ignition problems
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Mon, 09 June 2003 02:33
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ok kewl all information has been usefull...
today i looked at my plugs and they were fouled up to the shithouse.. i put new ones in.. well not new ones but good ones and they fouled up really bad when i took it up the road and back.. what i am trying to say is why are the plugs fouling up so quickly? could it be a faulty dizzy?
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Location:
Brisbane
Registered:
December 2002
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Re: ignition problems
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Mon, 09 June 2003 10:14
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It all depends on what you mean about fouling up. IF they are looking a bit gummed up it sounds like too much fuel. I didn't think that if your plugs were having problems it was electrical, I thought that meant it was fuel??
When you took it up the road was it miss firing? not sure what the problem is. give the carbs a tune
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Location:
brisbane
Registered:
March 2003
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Re: ignition problems
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Mon, 09 June 2003 10:57
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yeah.. i tuned the carbs bout 500k's ago was always really good after then.. this problem with fouling plugs just started on saterday 2 days ago... thats when this running rough prroblem started.. it done the same thing as since saterday whern the plugs fouled up.. they are real dark black so yeah it is fuel.. but i dont know if it is a spark problem under load or anything cause when i rev it hard on the spot it is ok.. only when i drive it it happends.. it has really driving me nuts of what it is i mean.. one 200m drive and it has done it.. didnt even get to drive in 2nd properly i am thinking it might be carbs but also think it might be something else it is very weird.. it feels like it is not egttin enuff spark out of the plugs.. 1st revs out well but then 2nd is really bad.. i guess you can say it is a phantom problem if anybody may know what it maybe it will be very helpful... oh yeah ti does missfire afterwards when i drive when i put a load on it.. it dont haveta be much of a load either this is all after i have put it in 2nd.
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Location:
brisbane
Registered:
March 2003
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Re: ignition problems
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Tue, 10 June 2003 11:46
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i am getting it checked out tomorrow.. my boss says it is a vacumn/ carby problem. will see what happends tomorrow
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Location:
Brisbane
Registered:
December 2002
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Re: ignition problems
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Tue, 10 June 2003 23:09
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And you say it has just started doing this. I had a problem like this but it was because I put the distributor back in one cog tooth too advanced. it was fine at idle and revved OK, but when put under load it coffed and spat and farted like crazy.
worked out that when the timing advanced because of the vacumm it was starting to spark on the next plug. just a thought though.
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Location:
brisbane
Registered:
March 2003
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Re: ignition problems
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Wed, 11 June 2003 07:49
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did it foul up your plugs after that run? i dont have my vacumn advance hooked up
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