Intermittent Misfire...

LokiRx7 · 04-25-2008, 03:58 PM

Okay, I have an 86 N/A that had been sitting neglected for five years. I have gotten it running and moving, and had to replace a ton of stuff to get to this point.

I have an intermittent misfire that I only notice at idle, I changed the plugs and after awhile it came back. When I first started driving it, it had a dead cylinder, I seafoamed the oil twice and it is alot better. The car only has 130,000 on it, and it burned alot of oil obviously when it had a dead cylinder, but the more I drive it the less oil it burns, leading me to beleive the rings simply needed the crap and sludge burned out of the ring lands so they could re-seat. (before I ever started it, I made sure to pour about an ounce of oil into each cylinder and cranked it a few times with the coil disabled)

Now I had to replace the two metal coolant pipes under the intake. I beleive one of the seals on them is leaking, causing air bubbles in the system.

Now when I had the dead cylinder (it was #4) the plug in that cylinder was COATED in oil. Now it looks normal, its a whitish grey color. It has some carbon deposits (chalky looking) as do all the plugs.

The car isnt overheating, but I think I may have a BHG, leading to the miss. Any thoughts or ideas would be great, I have no oil in the coolant or vice versa. But if you guys can think of anything else to check I would appreciate it.

LokiRx7 · 04-25-2008, 09:49 PM

Tracked it down to detonation, its pretty bad too, flattened out cylinder #3's plug.

Any ideas as to why I have detonation? I think its running a tad lean, sure smells that way.

LokiRx7 · 04-26-2008, 06:07 PM

Changed my AFM to one off of an 89 GT-S Corolla. Now shes spitting black smoke and smells a little rich. Just the way I like it

Kevman · 04-30-2008, 01:05 AM

..If you don't plan on smogging it

LokiRx7 · 04-30-2008, 02:14 PM

Nope, dont have to around here. I had to replace the IAC and the TPS, both had corrosion inside of them. Probably from sitting in the elements for five years. I am getting pretty close to being finished.

04-25-2008, 03:58 PM	#1 (permalink)
LokiRx7 MR2 + Flat Black = FAIL Join Date: Jan 2007 Location: N.C. Ohio Posts: 320 Thanks: 0 Thanked 15 Times in 14 Posts iTrader Rating: (1/100% )	Intermittent Misfire... Okay, I have an 86 N/A that had been sitting neglected for five years. I have gotten it running and moving, and had to replace a ton of stuff to get to this point. I have an intermittent misfire that I only notice at idle, I changed the plugs and after awhile it came back. When I first started driving it, it had a dead cylinder, I seafoamed the oil twice and it is alot better. The car only has 130,000 on it, and it burned alot of oil obviously when it had a dead cylinder, but the more I drive it the less oil it burns, leading me to beleive the rings simply needed the crap and sludge burned out of the ring lands so they could re-seat. (before I ever started it, I made sure to pour about an ounce of oil into each cylinder and cranked it a few times with the coil disabled) Now I had to replace the two metal coolant pipes under the intake. I beleive one of the seals on them is leaking, causing air bubbles in the system. Now when I had the dead cylinder (it was #4) the plug in that cylinder was COATED in oil. Now it looks normal, its a whitish grey color. It has some carbon deposits (chalky looking) as do all the plugs. The car isnt overheating, but I think I may have a BHG, leading to the miss. Any thoughts or ideas would be great, I have no oil in the coolant or vice versa. But if you guys can think of anything else to check I would appreciate it.

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04-25-2008, 09:49 PM	#2 (permalink)
LokiRx7 MR2 + Flat Black = FAIL Join Date: Jan 2007 Location: N.C. Ohio Posts: 320 Thanks: 0 Thanked 15 Times in 14 Posts iTrader Rating: (1/100% )	Tracked it down to detonation, its pretty bad too, flattened out cylinder #3's plug. Any ideas as to why I have detonation? I think its running a tad lean, sure smells that way.

04-26-2008, 06:07 PM	#3 (permalink)
LokiRx7 MR2 + Flat Black = FAIL Join Date: Jan 2007 Location: N.C. Ohio Posts: 320 Thanks: 0 Thanked 15 Times in 14 Posts iTrader Rating: (1/100% )	Changed my AFM to one off of an 89 GT-S Corolla. Now shes spitting black smoke and smells a little rich. Just the way I like it

04-30-2008, 01:05 AM	#4 (permalink)
Kevman L thinks you're Kira Join Date: Mar 2008 Location: Inland Empire Posts: 70 Thanks: 1 Thanked 3 Times in 3 Posts iTrader Rating: (0/0% )	..If you don't plan on smogging it

04-30-2008, 02:14 PM	#5 (permalink)
LokiRx7 MR2 + Flat Black = FAIL Join Date: Jan 2007 Location: N.C. Ohio Posts: 320 Thanks: 0 Thanked 15 Times in 14 Posts iTrader Rating: (1/100% )	Nope, dont have to around here. I had to replace the IAC and the TPS, both had corrosion inside of them. Probably from sitting in the elements for five years. I am getting pretty close to being finished.