yotarunner

I have recently purchased a 1994, v6, 4x4, 4runner that the manifolds are getting red hot and i put $20 in gas and maybe got 75 miles out of that, its like it is pouring it out the rear. It also has no power. The check engine light is on but the only code is the knock sensor. I have also had the exhaust check and it is not stopped up, the only thing i havent checked is the timing and wondering if that could cause it or if anyone had any helpful hints.

yellowspeedracer

sounds like it's probably running pig rich. there's so much fuel in the cylinder that it can't all burn before the valves open so the rest is burning in the manifold. could be an O2 sensor.

Juggalo

That's typical for the 3VZE at first, I just learned to deal with the fact that I can't pass anybody and get over in front of them before merging on the highway, it sucks especially after being used to a turbo Eclipse:cry:

As far as your check engine light, mine came on and said it was the "starter" censor. About a week later it went away and hasn't came back again.

I have no idea why your manifolds are red hot, it's not like you have a 800hp turbo car

yotarunner

thanks for the reply but if it was a o2 sensor wouldnt through a code

yotarunner

i was also wondering if it could the fuel rgulator pump. got to figure out because im scared its going to catch on fire and ready to go hit some mud.

zedex

Red hot exhaust manifolds is NOT normal. Have you ever had the timing belt checked. Over advanced timing or out of timing i think the problem could be but it certainly is not normal. Get it checked out.

Churnd

Your cat is probably clogged. Did they check that when they checked the exhaust? I just wonder b/c every time I've seen somebody with a red hot manifold, the cat is always the culprit.

Highland Runner

Your cat is clogged. Go out and either gut it or get a new one. This happeced to me also. The Runner wouldn't go over 50 MPH and it ran very hot. Manifolds were glowing so bright it light the underside of the car at night. I took off the cat and 90% of the middle was melted blocking the flow. I used a piece of rebar to knock out the entire inside. Put it back on and had power I never knew was there. It actually passed emissions also, but barely.

zedex

A buddy of mine had the same problem except a nissan. He cut the cat off and still had the problem. I should check back with him to see if he resolved the problem.

yotarunner

thanks for all the replys but i already have had the exaust off. Also wondering if vacum lines could be in the wrong place because someone has worked on it before me and the chilton manual is not real clear on the diagram.

rollandfayssoux

a buddy of mine had the same problem in a ford pickup. he told me that the manifold had a crack in it.

my .02

oly884

#1 check your timing, it happend to me, and that was the problem.

Ducky

juggalo:

Lol I remember that... my gsx... Always would pull off to the side of the road after I was done playing and look at the glowing manifold...

95_4X4Runner

I believe the timing also. When I got my 85 Supra, the engine was shot. I looked at the engine at night, and I could see the whole exhaust manifold glowing orange. It was caused because the last tech to replace the timing belt didn't tighten the crankshaft pulley bolt enough (~175 ft/lbs), and it wobbled loose and ruined the crankshaft. I took the timing belt cover off, and put a 19mm socket on the crank. I could turn the crank a good 30 degrees before it would catch and turn the camshafts (there should be no play between the crank and timing belts). That might be something to check out, if it isn't too hard to pull off the timing belt cover. Maybe take it to a stealer for their recommendations, they've probably already saw a similar situation.

(I installed a JDM used engine, and was extremely pleased, $650 delivered to the auto hobby shop on my military base)

Unhappy99

Timing is the culprit here. Not only must it be set 'on time' at idle, it also must advance as RPMs increase. From what you describe, it ain't advancing. I am not familiar with what mechanism advances the timing on your model year, but it appears (from what you have written) that it is ECU controlled, accepting inputs from a variety of sensors, such as knock, CrankPosition, CamPosition, etc....

The knock sensor certainly affects the ECU timing. In modern engines, the ECU advances timing up until light knock, getting the most power out of your fuel. If your knock sensor is giving bad info, then the ECU is reacting accordingly, and might not advance timing.

95_4X4Runner

That is a good point, when the knock sensor detects knock, it retards the timing, to get rid of the ping, so if it's set as being bad by the ECU...that's probably the problem.

The senior mechanic at the Toy dealer who changed my engine recommended that I spend the $~10 for a new section of the knock sensor harness that often gets too baked from the heat, and breaks down with age. It sounds like it's pretty involved to change out, the intake would have to come off, as it's under there somewhere.

frost203

Had the exact same problem turned out to be the throttle position sensor out of adjustment. Super rich condition,Cherry red exhaust man, no power, BAD mileage.

-FROST-