Scotto6591

I have a 1994 pickup 22re motor has been refreshed new head gasket,timing chain, all gaskets etc. when I start it has very little throttle response and the down pipe gets extremely hot and glows red after about 10 seconds after running.does anyone know what this could be and how to fix it?

snobdds

Catalytic converter is plugged up creating a restriction.

Or your running super lean, but the O2 sensor will correct the fuel trims to correct that, if good.

Scotto6591

Has newer cat and o2sensor

osv

don't run it like that!

did you adjust the valves, and set the timing?

Scotto6591

I adjusted the valves cold but not warm do to downpipe issue and I haven't been able to do the timing gun on it for the same reason

osv

i'm thinking that it's gotta be: 1)retarded timing 2)super lean 3)plugged exhaust 4)tight valve allowing burning gas into the exhaust.

does the cat have a front flange, that can be disconnected? run it open pipe, see if it heats up.

pull the plug(s), see if they are white from being lean.

i would adjust the valves again, and check the static timing at that point.

Terrys87

iTrader: (1)

I have dealt with a Cherry Manifold https://www.yotatech.com/forums/f116...nifold-196774/ but have never seen a Cherry Exhaust. I have even sent mine to Toyota and they say everything is fine. I have also dealt with other mechanics that specalize in Toyotas and no luck. I know it is not correct and only drive the truck a mile a week to keep everything lubed up until I can get the chance to do a whole engine and wiring harness swap.

Some of the components I have checked.

AFM... Manuals have some great checks for it. It will not always throw codes.
New Denso Throttle Postion Sensor.
New Denso O2 Sensor.
Removed Catalytic Converter.
Cleaned and tested EGR.
Timing is number one cause. I have seen that but it is not my issue on this one.
Cleaned and tested all sensors. Manuals are good for these checks.
Checked valve adjustment.
Checked Knock Sensor.
Checked all Vacuum Hoses.
Swapped Computers twice.
New Fuel Filter.
All fuel lines are clear.

I even swapped in a new Exhaust Manifold and was sure it would not fix anything but thought it may just of been thin and worn out. The only thing I can think of next is the Injectors and really dont see that being an issue but am willing to try it. Hope to get on it soon. If that doesnt fix it, engine and harness swap is next.

One thing I think and really cant figure it out if I am correct is, When the motor is started, it is in Closed Loop, after about 5 miles, the motor gets warmed up and goes into Open Loop and that is when mine gets Cherry. I can feel a loss of power and pop the hood and the manifold is glowing.

I dont know what all is involved in Closed and Open Loop. I have done some rebuilds, several top end rebuilds and numerous repairs on these motors and this one has me stumped and a few others in my area that know these motors.

Check your manifold at night and I would suspect you will see it red as well. Just never seen a glowing exhaust pipe. I am sure there are a few other things I have not mentioned and will add them when I think of it.

snobdds

If this was me I would eliminate a restricted exhaust system first. I would take the cat out and eliminate that variable. Then see where you're at. If it doesn't solve it then you know it's running lean and you have to figure out why. An engine needs Air, Fuel and a properly timed spark. That's when it gets a bit more complicated to fix, but it will teach you a lot about the motor.

Scotto6591

I ran it with no exhaust on and it still did it. I'll check the valves, spark plugs etc in the morning

scope103

Could be all sorts of things, but it is almost certainly ignition timing. Do that first.

Scotto6591

Think I found the problem the cam shaft caps where on there so tight I couldnt move it by hand with the rocket assembly and chain off. The valves are nice and white,

dcg9381

The valves are white because you're letting still-burning mixture out the exhaust valve. My guess is timing, which is pretty easy to check. Check not only for static timing after jumping, but make sure it advances (unjumpered) when revving the motor. My guess is that it's not advancing much.

The valves have now croaked - sounds like you've now got bad bearings or bad bearing surfaces, maybe both.