Little problem

[DSMxTSi]

Ok, since changing the timing belt, pulleys, water pump, cam seals, and front o2 sensor the 420A has been acting fucked up. Never had ANY problems with the car before and it's timing was off a couple teeth on the cam gears for the last two years, found that out when removing the old belt :eek: , and the old o2 sensor was dead. Even without a C/E light anymore it seems as if something bad is going on. At 100% throttle only it goes 100% lean, seems absolutely fine at any other throttle position. How do I know 100% lean? At wot the A/F gauge pegs down in the bottom most red and the car loses ALL power. For obvious reasons I do not floor it anymore. The couple of times I did have it at 100% throttle, though only a second or two, it then made a bad knocking sound from the internals afterwards. At first I feared it was a rod knocking or maybe a valve hitting a piston (it was in rythm with the firing order, if that makes any sense) but the noise disappears after shutting the car off and letting it cool down for a little while. I can drive the car all over without going full throttle and it's just fine. The knocking only started after those couple of times when it was 100% lean. It never did anything like this before. Then today after work it was raining hard and it could hardly accelerate till it warmed up, just sputtered pretty bad and the A/F gauge was fluttering instead of sweeping (if THAT makes any sense) :rolleyes: Again, never did that before. The timing marks are now correct otherwise the C/E light would be on. Changed plugs shortly after the timing belt change. Fuel filter is only a few months old. Fuel pump and injectors have never been replaced/cleaned. Car has 111K miles and has more power now that the timing is correct, up until full throttle. Can knock be so loud that it could be mistaken for a rod knocking, spun bearing, etc?? The 420A does not have a knock sensor like the 4g63 does.

Cody

[DlandryTSI]

if you do par throttle all the way to 7k is it fine as far as the A/F goes? If not check the filter and pump.

--Dave

[OneSlowEclipse]

Does this have anything to do woth Brian's post about spun bearings on 2gnt? They were saying that the knocking will get worse as the car warms up because the oil becomes thinner. What really doesn't make sense is the car going 100% lean. Just out of curiosity, why would it be knock? I'm sure it happens sometimes in a n/a 420a, but not in the proportions you are talking about. I wouldn't think we would get into the temperatures that would cause detonation.

Another stab in the dark, but how long has it been doing this? It couldn't be the ECU just trying to figure everything out since you got the new o2 sensor AND set the timing correct? Whatever it is, it doesn't sound good. :(

[Van]

Fuel filter first. Even though it's newer, one bad tank of crap could kill its flow at wot

Did you make sure a Mitsu o2 sensor went in?

You can knock so loud that I'd hear it in my car next to you, but that is oh so bad! Way bad, mondo bad, hella bad...

Fuel filter ASAP, then report back.

You can actually monitor your fuel filter's health with your a/f gauge/meter as long as you don't change anything else. I've seen it.

[303Racing]

I agree w/ Vern as far as the fuel filter goes. It's cheap and easy to replace do that first.

I will try calling you Tuesday morning sometime.

[DSMxTSi]

Dave, if I'm at part throttle, at any rpm, then go to redline it is just fine. A/F gauge reads in the rich LEDs too.

Jason, the knocking/ticking only happened immediately after the couple times I went WOT, then disappeared after shutting the car off and letting it sit for a while. Fortunately it hasn't happened at any other time, thus why I think it was "knock" and not a spun bearing. Also, this crap started as soon as I was finished with the timing belt change, never before.

Vern, since this started immediately after the timing belt change I have not associated it with a bad fuel filter since it was changed just a couple weeks before we moved back here, but I will keep it in mind. After talking to Brian we both agree that it's most possibly the injectors, his 420A acted almost identical then he installed the DFI along with new/bigger injectors and the problem went away. Since the car was WAY under powered (Jason knows as he drove it once) for the past two years due to the cam gears being off a few teeth it must not have had enough power to cause the injectors to misbehave this bad. It definately has a lot more power, just not at WOT. :rolleyes: I'll remove the injectors in the next few days and get them cleaned/balanced, then I guess we'll see................

Cody

[303Racing]

Like I said, off the top of my head the injectors would have to be my first guess. I still say try the fuel filter first just because of cost and ease of install. Take it for a drive and see what happens, then pull the injectors if it still persists. Your out what 5-7 bucks.

When the spark plugs, wires and coil start to go south the cut out or "sticky spots" are way more consistent and happen throughout the rpm band, 99.9% of the time you will get a CEL. The 420a has knock sensors but they are not very good at picking up small amounts of knock even when you can hear it. You will get a flashing CEL when it detects knock and it pulls timing big time. I can show you if you want :D

If the map sees positive manifold pressure it cuts out fuel like you are describing. Also when you max out your injectors (100%) duty cycle they do what you are describing. If they are dirty, old and decrepit I could see them doing that, shit they only have 100k+ on them.

I don't get the "noise"? Perhaps knock or something else? Did you get lock tight on those engine mount bolts and crank them down good? It might be a loose mount knocking around.

If you still lived down the street we could get it figured out in an afternoon. I've got at least two of every sensor and at least 8 stock injectors in the garage.

Have fun getting the injectors out, its real easy. ;)

Keep me updated
Brian