3.0 misfire?
#1
Registered User
Thread Starter
Join Date: Jun 2008
Location: El Paso, TX
Posts: 142
Likes: 0
Received 0 Likes
on
0 Posts
3.0 misfire?
I had changed out my spark plugs (pre-gapped) and wires recently. Two of my wires were damaged from not being suspended properly and touching the manifold. After if burned, it started misfiring. I bought the exact same set of wires, and replaced the damage ones. It runs fine from a cold start, but after heating up, starts misfiring again.
This is a 1991 4runner 3.0 4x4 Auto
What is wrong?
This is a 1991 4runner 3.0 4x4 Auto
What is wrong?
#4
Registered User
Join Date: Mar 2008
Location: Temecula Valley, CA
Posts: 12,723
Likes: 0
Received 4 Likes
on
4 Posts
well...
I never trust pre-gapped plugs since the same plugs work on different engines and gaps may be different, so start there and make sure the plugs are gapped according to your engine's specs.
also, check the ignition coil resistance to make sure that the shorting wires didn't damage the primary windings in the coil.
I never trust pre-gapped plugs since the same plugs work on different engines and gaps may be different, so start there and make sure the plugs are gapped according to your engine's specs.
also, check the ignition coil resistance to make sure that the shorting wires didn't damage the primary windings in the coil.
#6
Yeah.. I have the same type of problem with my 92 v6.. once she warms up .. it starts missing.... well probably misses the whole time just more noticable after the idle comes down.
The plugs were done by the last owner, and i just changed the wires .... with no results...
The plugs were done by the last owner, and i just changed the wires .... with no results...
Trending Topics
#8
Contributing Member
Join Date: Apr 2006
Location: TENN Native Languishing in Virginia
Posts: 4,787
Likes: 0
Received 34 Likes
on
14 Posts
missing after warmup denotes a vacuum leak, usually. There are miles of vacuum hose on these engines and they're getting up in years, so cracked hoses are common.
#9
Registered User
Thread Starter
Join Date: Jun 2008
Location: El Paso, TX
Posts: 142
Likes: 0
Received 0 Likes
on
0 Posts
#10
any luck finding your leak?... When I pump my brakes the stumble gets alot worse and brings the rpm's down.
I have sprayed all visible vacuum lines...but I haven't been able to find anything yet
I have sprayed all visible vacuum lines...but I haven't been able to find anything yet
#11
Registered User
Thread Starter
Join Date: Jun 2008
Location: El Paso, TX
Posts: 142
Likes: 0
Received 0 Likes
on
0 Posts
My apologies for taking a while to reply; I was out of town. I just replaced the majority of my vacuum lines (one of which I found to be torn) and I still get misfire. I feel it mainly at idle and after the engine heats up.
Any more options?
Any one?
Any more options?
Any one?
Last edited by Texas91Runner; 04-21-2009 at 10:10 PM.
#12
Registered User
Thread Starter
Join Date: Jun 2008
Location: El Paso, TX
Posts: 142
Likes: 0
Received 0 Likes
on
0 Posts
I would really like to know what's wrong. My runner never did this before the swap of the plugs and wires.. I'm most-likely going to check the resistance of the current coming from the distributor next if I can find my instrument. I'd probably suggest you guys doing the same.
Last edited by Texas91Runner; 04-21-2009 at 10:10 PM.
#13
I haven't changed my vacuum lines out yet, but I can hear a very high pitched sound when the truck is idling I cant seem to find where its coming from.
I have changed my cap, rotor, plugs and wires. Mine is the same as yours, when sitting at idle, I notice the stumble as it mildly shakes the truck.
Does your idle decrease and get worse if you pump the brake quickly?
Mine seems to drop and get rougher when I do this.
I have changed my cap, rotor, plugs and wires. Mine is the same as yours, when sitting at idle, I notice the stumble as it mildly shakes the truck.
Does your idle decrease and get worse if you pump the brake quickly?
Mine seems to drop and get rougher when I do this.
#14
#15
I honestly can't feel the stumble while driving at all. In my case, I can feel and hear sudden bursts from the exhaust (mostly while idling), but when under the hood the engine doesn't appear to be much off pattern.
I would really like to know what's wrong. My runner never did this before the swap of the plugs and wires.. I'm most-likely going to check the resistance of the current coming from the distributor next if I can find my instrument. I'd probably suggest you guys doing the same.
I would really like to know what's wrong. My runner never did this before the swap of the plugs and wires.. I'm most-likely going to check the resistance of the current coming from the distributor next if I can find my instrument. I'd probably suggest you guys doing the same.
#16
Registered User
Join Date: Jan 2012
Location: Fairfield, CA
Posts: 54
Likes: 0
Received 0 Likes
on
0 Posts
I know im 4 years late. but im having the same type of problem. truck sounds good while warming up but at a warm idle you can hear it missing. I change the plugs, cap, and rotor it seemed to get a little bit better but not completely. I was reading on other threads and i think maybe a valve adjustment can fix this.?? any input?
#17
Registered User
Join Date: Jan 2012
Location: Fairfield, CA
Posts: 54
Likes: 0
Received 0 Likes
on
0 Posts
Okay. Sorry to post my problem on this tread but It seems my number 3 cylinder is the problem. Compression is only at 30 PSI, while all others are 175-180psi. Please help with any added info.
Thread
Thread Starter
Forum
Replies
Last Post
nvwiggins
86-95 Trucks & 4Runners (Build-Up Section)
13
06-16-2016 03:05 PM