This Montero has really become my cross to bear. It is back on the road again after a severe overheating problem cracked both the heads. I suspect one of the heads was no good from the get-go, but I can't prove it, so.....

Regardless, it's back together and running except it pings. Alot. It's definitely not rod knock, but unless I feather the gas off the line, it pings. If I hit passing gear, it pings. Timing is right on. I grounded the test lead and set it at 5 degrees. The only thing different from the original setup(which didn't ping) are the injectors. I had obtained a set that had lower mileage, so I used those. Maybe there's one that has a bad spray pattern and is causing a lean condition. Guess it'll cost me an intake gasket and a Saturday to find out, but as always, I'm open for other ideas.

*Check the marks on the side of the injectors to make sure they're the correct ones for the engine. IIRC, they should read "INP-051", but I can check that if you can read the numbers.
*Try another ECU.
*Try another distributor.
*Check the fuel pressure - if necessary, replace the regulator and/or fuel pump.
*Check the engine coolant temperature sensor - the one that signals the ECU.
*Check the air intake sensor.
*Check the EGR system.

Do you know how much the heads may have been milled?

Are the cams timed correctly?

Have you checked the harmonic balancer timing mark against the mark on the crankshaft sprocket/oil pump to see if they agree? If not, you have a spun balancer..... not too uncommon on these engines with age.

I would suggest pulling some spark lead out of it and see if the pinging quits.

Frank

They also ping like crazy with an overheated head, much as I hate to mention it. Could you have the wrong head gaskets, a blocked radiator, or bad thermostat?

Thanks for all the things to check. I think I'll park it until I can better figure things out. I don't want to deal with any more serious engine damage.

The injectors are off of the same year Montero as I pulled them myself. Doesn't mean they are correct, but.......

The replacement cylinder heads were from Cylinder Heads International. I had heard good things about them, so I put a set of their heads on.

Sensors, ECU, and everything were fine before the meltdown. Timing marks were all aligned per the factory manual. I did not check to see if the crank damper mark aligns with the sprocket mark, but that shouldn't be too tough to do now.

I was really hoping to be done with this thing. I am SO tired of wrenching on it.

Again, many thanks.

Quick update: I just took the truck home to swap for the Raider. Temp climbed to about 1/2 on the factory gauge and the puke tank was bubbling when I shut it off. This is not a good sign.

Maybe your coolant system needs a little more "burping". I burped mine by using the heater hoses. The highest hoses on it. Worked pretty well.

I also used a thermostat with the little toggle on the disc part; supposed to help dispell air...I think.

Always let the engine coolant warm up to the touch before putting the radiator cap back on and road-testing the vehicle.

Pull the radiator cap and the puke tank cap and blow compressed air through that line in both directions to remove any gunk that might be in there. Also check the puke tank itself for gunk in the bottom...remove it and clean it out if there is any crap in it.

Wonder if it's some silly problem like bad dist cap, wires, etc.?

Check your oil level to see if it is over filled and smells like fuel. If so, change the oil and filter.

When I didn't get the timing right on my new engine I cranked and cranked waiting for it to fire...and that just washed my pistons with unburned fuel. This resulted in fuel in my engine oil and I had to change the oil and filter before moving on.

No, not a good sign at all. This is what I meant about hot heads causing pinging. The very first thing I would do is a compression test, followed by a combustion products in the coolant test (you can buy a test kit from Lisle at most good auto parts stores to test this) and/or a radiator pressure test. I'm pretty sure you have a head gasket leak, or a cracked head. In addition, did you have the radiator rodded out? My experience is that just doing the heads leads to just doing the heads again, because most heads fail due to a chronic overheat from a clogged radiator. I'd also check the block deck for flatness. Before pulling the heads, I'd pull the head bolts one at a time, grind a couple of threads off the end, and retorque the heads. Look at FrankR's sermons on head bolt length and cleaning the head bolts holes to the very bottom with a tap. It's VERY possible to get a correct torque reading on the head bolts and never get good clamping force on the gasket as the bolt bottoms in the hole or hits dirty threads near the bottom of the hole.

I'd assume you are losing coolant, too.

Sorry, but I'm pretty sure I'm right on this one.

Sounds like you're gonna have to re-do the heads, Flush the heater core & radiator. I fond it was less expensive to replace the radiator.http://www.yourautocoolingsource.com/site/823209/product/CU1384

I hope that I'm mistaken in your case about the heads. <img src="/forums/images/graemlins/scared.gif" alt="" />