mini-wini-dan Posted June 28, 2013 Share Posted June 28, 2013 I see .30-.32 in one reference and have commonly used .35 on other engines. Any comments on this for best performance? Any reference on where to get a shop manual for an 86 truck? My owners manual is mostly covering the camper specs. Quote Link to comment Share on other sites More sharing options...
Boots Posted June 28, 2013 Share Posted June 28, 2013 I see .30-.32 in one reference and have commonly used .35 on other engines. Any comments on this for best performance? Any reference on where to get a shop manual for an 86 truck? My owners manual is mostly covering the camper specs. Hi Dan, I had this unit, and a 22RE engine and I did the same as you - .34 to .35; the advantage is better power at the low end (when you are drag racing off the stop light!) and of course you will get slightly less fuel economy and power at the top end. Boots Quote Link to comment Share on other sites More sharing options...
zero Posted June 28, 2013 Share Posted June 28, 2013 I see .30-.32 in one reference and have commonly used .35 on other engines. Any comments on this for best performance? Any reference on where to get a shop manual for an 86 truck? My owners manual is mostly covering the camper specs. Plenty of free factory manuals for Toyotas in PDF files at: http://www.yotatech.com/f128/toyota-factory-service-manuals-fsm-all-years-156128/ Changing the spark plug gap other then what's called for gains you nothing. The gap given is a compromise to give the best "safe" spark energy and least "leak" potential to ground (i.e. a short) via a plug wire or distributor cap. The wider you gap a plug, the more voltage it takes to fire it. The higher the voltage - the more apt a plug wire is to short to ground somewhere unless built for it. A wider cap also puts more stress on the ignition coil and can result in misfiring at higher RPMs unless the vehicle is built to sustain that higher voltage. Some engines will burn up the ignition systems if the plugs are gapped too wide. The higher voltage from a wider gap also means less miss-fires in an engine run at high RPMs IF the ignition system is designed to run at that high voltage. Chances are your Toyota is not and that is why it calls for a gap of .032" approx. If you installed a high energy ignition system along with better plug wires - then you could run wider plug gaps and probably not notice any gain in performance. It takes around 20,000-25,000 volts to fire a spark plug gapped at .032" using a conventional distributor. Note it takes 6,000 volts JUST to pass current from the rotor inside the distributor cap (also has an air gap). Conventional coils are rated at around 25,000-30,000 volts so all works fine. Open the plug gap to .035-040" and demand is raised to 35,000 volts or more. That exceeds the limits on some systems. Many modern autos with no distributors and high energy ignition systems along with plugs gapped at .050-.060" can make 80,000 volts when needed. The idea is to eliminate any misfires and keep emissions down. With your Toyota - you would not be able to notice any difference in performance or fuel mileage between a 30,000 volt system gapped at .032" and a 80,000 volt system gapped at .050. The higher voltage system would be more apt to start a flooded engine with fouled plugs - which I assume is not a common issue with Toyota RVs. I've got a Chrysler four cylinder, 105 horse boat engine from 1973. It came OEM with a "high energy" capacitive discharge igntion that would burn out when plugs got fouled or - if one plug wire fell off when running. They were .060" gaps. After having two systems fail on my - I converted it back to standard ignition and .030" gapped plugs. Never skipped a beat since and runs just the same. Quote Link to comment Share on other sites More sharing options...
mini-wini-dan Posted June 28, 2013 Author Share Posted June 28, 2013 So it will be my priority to run efficiently and use the recommended setting. Which is .30 or .32? Thanks for all of the info about the electrical system. Now one more question NGK or Bosch or ? Quote Link to comment Share on other sites More sharing options...
linda s Posted June 29, 2013 Share Posted June 29, 2013 Just buy your plugs at a Toyota dealer. They are not expensive and they will come pre-gapped Linda S Quote Link to comment Share on other sites More sharing options...
zero Posted June 29, 2013 Share Posted June 29, 2013 It's takes just a few seconds to check the gap on a spark plug. It would be silly to buy a new spark plug from anywhere an install without checking the gap first. EVEN from Toyota who does not make spark plugs. There could be a machine production error - or a plug could be simpy dropped -or removed- fiddled with and reboxed, etc. I've seen many come new with the incorrect gap. Sometimes it's error and sometimes one plug part # fits many different engines with different gap specs and the gap is generic. Toyota tends to use Denso and NGK OEM. In the 80s - standard OEM Densos were #3031 for around $1.50-$2.00 each from many sellers. If someone wants a plug with a longer life (in a fuel injected engine) -platinum or iridium plugs from Denso cost around $7-$8 each. They offer no gains in actual performance. Just last longer. Plantinum is pretty much standard OEM now in almost all cars and trucks due the emissions regs. I mentioned the longer-life plugs in fuel injected engines and not carbed. My reason is - most carbed vehicles lack electronic fuel mixture controls and burn dirtier. So the plugs often need servicing much earlier because they get coated with deposits - regardles of what they are made of. Newer engines burn so clean that the main issue with spark plugs is the metal burning away. Thus the shift away from steel/copper and over to platinum or iridium. Note there WERE a few cars with electronically controlled carbs in the mid to late 90s. Subaru made the last one sold in the USA in 1990 (Justy) as I recall. Quote Link to comment Share on other sites More sharing options...
mini-wini-dan Posted June 29, 2013 Author Share Posted June 29, 2013 Thanks for the info Quote Link to comment Share on other sites More sharing options...
WME Posted June 29, 2013 Share Posted June 29, 2013 Factory manual says .8mm or .031" Quote Link to comment Share on other sites More sharing options...
mini-wini-dan Posted June 29, 2013 Author Share Posted June 29, 2013 I just installed them (before reading your post) at 0.30- hope that is close enough-I had a real difficult time getting plug #4 to seat for threading. Thanks for the info though. Quote Link to comment Share on other sites More sharing options...
zero Posted June 30, 2013 Share Posted June 30, 2013 Having a slightly narrower gap means nothing in normal use and driving. It results is a slight benefit with a wet engine since the plug wires and/or cap are less likely to short to ground. Also makes is less apt to start if it gets flooded and plugs can foul a little easier. The reality is - you could set your plugs anywhere from .022" to .035" and never notice a difference. Quote Link to comment Share on other sites More sharing options...
tlava Posted September 8, 2013 Share Posted September 8, 2013 Hi Folks The plugs for my 84 22re came gapped at .zero 25 from the dealer so I guess that is right (question mark some of my keys dont work Quote Link to comment Share on other sites More sharing options...
straygoose Posted September 11, 2013 Share Posted September 11, 2013 I just swapped out my plugs a couple weeks ago, and I asked the store clerk to look up the gap on the computer. I believe he came up with .034 for the NGKs I bought. Quote Link to comment Share on other sites More sharing options...
straygoose Posted September 11, 2013 Share Posted September 11, 2013 Just buy your plugs at a Toyota dealer. They are not expensive and they will come pre-gapped Linda S They quoted me at 4 bucks a plug. Went to the AP store, and asked for NGKs, and they were about six bucks for the set IIRC. 4 each isn't expensive, but it is clearly over-priced. Of course this is the same dealer that wanted about 300 for the spare tire tool kit. Dealers... Quote Link to comment Share on other sites More sharing options...
zero Posted September 11, 2013 Share Posted September 11, 2013 Depends what plugs they are. NGK, Bosch or NIppoDenso standard plugs ought to be $1.20 each. Platinum around $2.30 each. If you want something like double-platinum or iridium, then $6-$7 each. If the dealer is selling you a standard plugs e.g. a NGK BPR5EA-L or a Denso W16EXR-U for $4 each, it is a royal rip-off. Quote Link to comment Share on other sites More sharing options...
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