Recently while driving my 93 Toyota Pickup, I experienced a loss of power. It is equipped with a 5 speed manual transmission and a 22RE engine. The engine has about 165K on it. Any ideas as to cause? I am aware that it could be a timing chain, or additionally, there is a sensor in the air intake that I have heard could be the problem. Also, if it is a timing chain, what are the chances of engine damage?
Power loss?
Check engine light?
How well maintained is it?
This is a distributor-based ignition system; have you tried a tuneup, including a new rotor and distributor cap?
Beyond that, there are tests you can run to determine if the problem is fuel delivery (or metering) or ignition related. I’d suggest starting with diagnosis rather than throwing parts at it. I’d start with the ignition system first.
If the timing chain is wearing out, it’ll start to rattle. It sounds a lot like rattling lifters, but very loud. I’ve heard a bad one on a 22R engine, and it makes a racket. It’ll also show up on vacuum readings. As will a vacuum leak if you have one. Since you don’t mention rattling, I’m betting that isn’t the cause.
Could also be a plugged exhaust. These have a very simple muffler-shaped cat converter in the middle of the exhaust, and the ceramic honeycomb inside can break down, crumble, and block the outlet of the converter. That’d strangle the engine, presenting as power loss.
Could also be a malfunctioning injector in the throttle body not allowing sufficient fuel or not vaporizing it properly.
Start with diagnosis, then move to repair.
I have a Corolla of similar vintage, M5 manual transmission and 4afe engine. I can’t speak to the 22RE, but if my 4afe had that symptom and no stored diagnostic codes, first thing I’d suspect is the ignition timing is somehow too retarded. That’s easy enough for a mechanic to check. I’d discount the timing chain idea, unless there’s unusual noises you are hearing. Beyond that, here’s what I check, in roughly this order
- Engine air filter condition
- Condition of spark plugs, distributor cap, ignition rotor, and plug wires
- Compression
- EGR
- Valve adjustment
- Plugged cat
- Fuel pressure
Feeling lucky? If you’ve never run a couple doses of fuel injector cleaner through it, that might be worth a try.
Edit: If it seems to missing at idle rpm, check for vacuum leaks too.
If this came on suddenly and is a significant loss of power I would suspect a failing fuel pump, fuel filter, clogged converter, or the ignition timing has jumped for some reason and is running way retarded.
That stuff is all easy to check.
Run It at night and get a load on the engine. After the engine is good and hot, pull into a good parking spot, and visually inspect the converter.
Is it glowing even slightly?
A glowing converter can be the sign of either a clogged converter or fuel burning off inside the converter.
That may help narrow down your symptoms to a few probable causes.
You may not find a glowing converter, but it’s worth a shot.