sdyacht

I've searched through a lot of threads and I've not really found a solution.

1995 4Runner V6 2wd w/ AT @ 112k mi.

Here are the symptoms, and codes. Please help me if you can. This has been going on for about 2 days now...

Starting the truck, cold or warm or hot, the idle and rev'ing up is rough...the whole truck shakes, and it's obvious something is wrong. Almost feels like a missing cylinder.

There are no metal sounds like a bearing or something spun inside the engine. No ticking of valves, either.

From a dead stop, the roughness is noticeable as I accelerate. It starts to go away as the speed get higher, but there is 'significant' power loss. I'm guessing that is because I press the pedal down farther to start from a stop.

Starts up fine, no problems there.

Doesn't stall, but it feels weird, so I put it in neutral at stop lights.

Oil is new and clean.

I made no recent changes to the engine when the problem started...it just seems to have 'just happened.'

I put new plugs, wires, cap & rotor on about 6 months ago.

New fuel Filter about 5 months ago.

New timing belt about 8 months ago.

New EGR valve 2 months ago.

New O2 sensor(s) yesterday.

There is no smoke from the exhaust.

Trouble DTC codes are 12 & 25


So I'm really stuck trying to figure this out...any ideas?

Is there a way to test for a blocked fuel injector?

I have a PVC valve to install, but I haven't done it yet, because of how hard it is going to be to get to it.

nygaard208

what did you put in for spark plugs?

my friend put some of thos platnum e3 plugs in his 22re and it had no power and sputtered like crazy. so i told him to get a set of ngk's and that made the truck run like a top.

abecedarian

Runs rough so I'm going to guess you've already checked the plugs.
but
code 12= No NE, G1 or G2 signal to ECU within 2 seconds after starting to crank the engine. Sounds like a loose connector around the distributor or igniter.
code 25= Fuel ratio lean. Well, no wonder it's lean if it's not getting proper signals from the distributor with regards to crank position. Again, sounds like a loose connection around the distributer or igniter... but can't rule out wiring to the O2 sensor either.

TNRabbit

Pull the vacuum hose that connects to the EGR valve control. Does it smooth out?

sdyacht

Yeah, I'm an idiot. Last night as I was working on the truck into the dark hours of the night, I decided to start the truck to see if anything changed. But what I discovered was the #5 spark plug wire came out of the loom and was resting against the EGR down tube. I can't believe that I hadn't already found that sooner.

Thank you for everyones help. This board is a great resourse!

charles_and_rebekah

I have the 1995 5speed manual 3.0 4x4. It is significantly underpowered. Changed the plugs, wires, rotor, and distributor. It quit idling very rough afterwards but it has to be shifted at HIGH rpm's to drive and it stills is underpowered. It has no clicking or popping sounds, and I was told that the timing was out 180degrees. Is that the possible problem? I need help! Please reply or contact me via email or phone (501) 655-9256 cfulton@harding.edu , sincerely
Charles (first time 4runner owner)