sluggish acceleration and loss of power (2000 toyota echo)

[kawana]

Hey everyone. Im having trouble with my wifes 2000 toyota echo. Its been getting progressively worse with acceleration. From a stop, you can put the peddle to the floor and it will SLOWLY accelerate to 20km/h at which point it will take off like a rocket. Going up hills it feels like its running on half power. No check engine lights are coming on, no codes are being thrown. The air filter was super dirty, so I replaced it yesterday and it ran like new for a few hours. This morning it was back to the exact same issue. I'm pulling my hair out, I dont know what could be causing this, that wouldn't be throwing up codes. Its also getting really bad MPG compared to normal. I have a OBDII reader, but I cant make sense of what it spews out. The mass airflow sensor was changed a year ago because it was having similar symptoms, but that time it was showing a check engine light, so I don't think its related.

[revelations]

How old are the plugs? Gapped?

[kawana]

Plugs are probably 1.5 years old. Just used whatever gap they came with.

[relyt92]

When you use the OBD scanner does it show any pending codes? Post them if it does.

[kawana]

Doesnt show any codes at all.

[RickDaTuner]

That to me sounds like an air restriction, either from the intake or the exhaust.

I would recommend removing the intake piping up until the throttle body, and checking to make sure there is nothing stuck in the intake pipe or throttle body on its own.
Also attempt to remove one of the 02 sensors before the catalytic converter and run the car, make sure that there is nothing that can melt or burn near the open o2 sensor port, and see if the car feels better, if that's the case, then you can punch out the cat, or have a new one installed.

If there is a restriction in the intake, like a very dirty filter, it will over fuel the air/fuel mix and cause a rich burn, resulting in an overload to the catalytic converter which overtime carbonizes the substrate and eventually plugs it solid.

other things to ask is if the engine is revving high with lack of power, or is it just low engine speed, and low power as well?

[AndyL]

Engine temp sensor. (Remember there's 2 one for guage one for ecu)

[kawana]

I was thinking a restriction as well which is why I put a new filter in. Like I said it ran perfectly for a few hours then crappy again this morning. I thought about a blocked cat but I thought a code qould be thrown.

[kawana]

I scanned the temp sensor and it seemed to be reading normal. Its the fact that it ran great for a few hours then stopped thats confusing me. I tried resetting the ecu but that didnt fix it. Might not have disconnected the battery for long enough though so ill try again.

[revelations]

Having it suddenly gain power sounds like an electrical/spark issue of somekind.

How do the plugs LOOK? Is one darker than the rest? Is one burnt?
Are they the proper plugs for the vehicle (iridium, eg.) ?

I would still check the gap, even though it probably isnt the cause of this issue.

[ercchry]

How is the fuel filter?

[kawana]

No idea of the fuel filter, i doubt its ever been done. Its probably long overdue but I dont know if that eould be the cause. Simple because it worked flawlessly after the new filter for a little while. Ill check the plugs as well.

[RickDaTuner]

Having had a look over the engine design, I would now come to suspect a clogged variable cam control solenoid, Toyota Calls it a Camshaft Oil Timing Solenoid, its on the left front of the engine or passenger side, it should be a 10mm bolt and a electrical connector, I would remove it and just make sure that the mesh screen is still there, and also that there is nothing blocking that same screen.

A failing cam or crank sensor will give you the same faults, but those would throw a code.

being that its a 2000 though OBDII was still a bit young, and CELs for cat monitoring, and rediness were not as broad as they are today.

[AndyL]

I had an 01 echo - that happened with mine... Dealer threw a shit ton of random sensors at it.

Good mechanic put a new temp sensor in it - all good. Could think it's hot and run open loop. Won't throw a code because it's actually all normal (just running hot/cold) where most other sensor failures get flagged.

You might have bumped a bad harness wire when you changed the AF too. That's always a possibility

[RickDaTuner]

^I'd definitely try what Andy is suggesting, of all the possible causes this is the cheapest and some what easiest fix (if you don't mind getting a little coolant on your hands)

Make sure to order the ECU temp sensor, and not a water temp sensor, as mention there are two, one for the gauge and one to run the car.

[kawana]

Ill look into the temp sensor. It is running rich i suspect, because of the poor mileage.

[kawana]

Havent tried any of these suggestions yet but I will this weekend. We had an unusually hot day yesterday and the car ran like garbage. A mechanic friend of mine suspected something was funky with the vvt because of the way it surges. Also there is a clacking aound when idling. He thought it was the timing chain but we havent looked into that yet. Simplest thing will be to check the screen as auggested by Rick. The engines pretty clapped out so my friend suggested putting in 5w40. Thought perhaps it was thinning put too much when hot. I still suspect its a temp sensor somewhere so Ill try the engine temp sensor if the screen looks clear. Ill also hook it up to my cheap obd2 scanner and post results, since I cant really make sense of it. It spits out voltage readings. Can anyone explain how I can tell whats normal and what isnt by reading these results?

[mr2mike]

I think you're over thinking this one. It's pulling timing but need to figure out why.

Temp sensor
Fuel filter
Clean MAF sensor (with proper cleaning agent & carefully).
Clean throttle body, possibly sticking.

Clacking at idle is a sticking valve, valve lash or needs reshimming.