Well, my newly acquired 87 4Runner's missing/injector problem has been diagnosed. Turns out the shop thinks it is a burnt valve. All the injectors tested out fine and compression is good in all cylinders. Apparently it is #3 and it just isn't doing anything. With 265k and running on three cylinders what is my best plan of action. Rebuilt, reman, used engine, 3RZ swap? I was advised by someone else that with that many miles, if I went to fix the valve might at well do the whole thing, not worth just fixing the valve on a motor with 265k. What do you all think?

Thanks!

 

If compression is good in all cylinders, why does the shop think the valve is burnt? What did the leakdown test tell 'em?

 

They haven't done the leak down test yet, said they would need more time and that if I wanted them to do that I could bring it in early next week. The guy at this point was giving me what he thought it was after 30+ years in the business and working on many toyotas. They adjusted the valves and when they did this is when he thought it was the valve. He said the leak down test would let them know for sure if it was the valve or something worse.

 

compression checked out fine and he thinks a valve is burned? what is the reason hes thinking its the valve then? I'd wait for the results of the leakdown test as leakdown testing is a lot better at pointing out where the problem is

 

I thought the leakdown test was only used if the compresson was bad. If the compression is good what's it going to tell you?

 

I thought the compression test tells you if its the piston rings that are shot... and thats it...Leakdown test tells you if its the intake or exhaust valves....

 

compression test tells you if you're losing compression, be it via bad rings, scored cylinder, hole in piston, or badly sealing valve. a leakdown test will give you a means of determining which of those is the problem. a leakdown test is pretty useless if compression is good, though.

 

Compression and leak Down tests explained.

http://www.myclassiccar.com/HowTo/re...ge/index.shtml

http://www.type2.com/library/engineg/leaktst.htm