Just did a tune-up - I think I may have found why bad MPG
#1
Contributing Member
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Just did a tune-up - I think I may have found why bad MPG
Replaced cap, rotor, plugs, wires. It had Bosch Platinums, and the gap on them was worn out to ~0.060! Contacts on the cap and the rotor showed A LOT of wear. With the price of gas, I hope this makes a difference!
Is there anything to read off the discoloration of the plugs?
Is there anything to read off the discoloration of the plugs?
#2
Registered User
so much for platinum plugs lasting longer, eh? i think that without a double platinum(both on ground and electrode) it'll still wear out just as quick as a normal plug.
replacing that stuff most definitely will make things better, though.
replacing that stuff most definitely will make things better, though.
#3
doubled platinums are useless unless you have the ignition for them. Those appear to me as a Double Platinum plug. Could be wrong. All Double Platinum sparkplugs any brand are fixed .060" gap. It's the ignition system that makes up for the huge gap. Most new vehicles made nowadays require a double platinum, because the ignition uses such a high powered spark, you need a sparkplug to handle.
Also in newer vehicles the lifetime of the sparkplug has increased tremendously! Your talking 100k miles to set of plugs! The recommendation for changing them is around 60k miles though.
Also in newer vehicles the lifetime of the sparkplug has increased tremendously! Your talking 100k miles to set of plugs! The recommendation for changing them is around 60k miles though.
#4
Registered User
actually platinum plugs take less juice to fire, making them a good choice for most ignitions. they are NOT necessarily pregapped.
the only plugs that require a super hot ignition are the surface ground(outboard motor) type. most domestic cars have a high energy ignition that calls for big gaps though, regardless of the plugs.
the only plugs that require a super hot ignition are the surface ground(outboard motor) type. most domestic cars have a high energy ignition that calls for big gaps though, regardless of the plugs.
#6
I found something very interesting when I did a tune up last weekend too. Just got my (new to me) 1990 4runner 22RE and it was running like crap....kinda. It was very smooth and seemed to run fine, but NO power. I just thought it was the crappy 4.10 gears and a tired old 22Re (188k). So first (had been planning on this anyways) I regeared to 4.88s from a V6 4runner. That helped but not as much as I'd hoped. Then I started tracking my mileage. Worst was 14.9 mpg best was (with highway!) 17.5 mpg. So I did an involved tune up which included some autolite plugs (0.031 gap), bosch plug wires, oreilly cap and rotor, and a bosch O2 sensor. Next I cleaned out the TB...found about a POUND of ccarbon buildup in there. Disgusting. Then I checked the timing..and found my MAIN problem (hindsight is 20/20 ). Factory spec is 5* Adv in diagnostics mode.... I was at 2* Retarded (NEGATIVE!)!! Well that 7* really helped, my first 90 miles I measured 18.6 mpg city, and my power is back up to where its supposed to be. I am planning to try advancing a little more (1 or 2*) and see if I can squeeze some more juice out of it wtihout pinging
Moral of the story: Always check the free things first hehehe
Moral of the story: Always check the free things first hehehe
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#8
I think your'e confusing diagnostics mode with normal mode - diagnostics mode is where you're supposed to set your timing. If you did not jumper pins TE1 and E1 in the diagnostics port (little grey box) then your timing will read 12* adv. (i.e. 12* adv in normal mode = 5* diagnostics mode). If you were to set it to 15* in diagnostics mode as soon as you put it back in normal mode you will be at 22* which is WAAYY too much!!
Therefore what you are saying is that I should try setting my timing up to 8* (3* above factory)...which is what I might try next
Therefore what you are saying is that I should try setting my timing up to 8* (3* above factory)...which is what I might try next
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scottyg486
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07-19-2015 05:34 PM