Another P0420 and P0300 error thread =-|

[MiataMike]

2000 SE (I appologize for the length of this thread)

I have read pretty much all the posts here in this forum about the P0420 and P0300 errors. I have followed all the instructions and repairs that were listed. And I'm still getting the same error codes.

Things that I've done:

1. Cleaned EGR Valve and EGR Ports/Intake manifold.
2. Replaced Coil Pack, Plugs and Wires
3. New air filter (Monster Flow)
4. Check engine compression (tested OK)
Relevent setup:

1. JR Racing Header
2. RB Mid-racing pipe + RB Dual exhaust (Pipe was drilled to insert the O2)
3. (No cats)
Symptoms:

1. When the car first starts up (Cold) and the auto-choke is on it feels like the throttle response is what it should be or as close to it as I've seen in a while.

2. Once the auto-choke goes off any time I press the gas pedal the car acts as if it wants to stall. (Very hard to get the car to start moving from a dead stop) (sometimes misfiring once every other week)

3. Once the car has been driven for about 10 minutes it drives OK but still not like it should; but it is drivable. (but still not that good from a dead stop)
The car acts like it has no power and no torque.

Past problems possibly related:

1. I had the timing belt replaced around 105K. When that was replaced the mechanic that installed it dind't put the crank case or valve cover back on correctly, causing the car to spew oil. After I realized there was a problem my car had over heated one time. I didn't think much of it since it still had the original hoses on it. So i cut the part of the Heater hose that had busted and put it back on went about my business. A few days or a week later a different hose busted. I then found out that it was leaking oil from the back of the head around the valve cover. (didn't know about the crank case not being bolted on until the new mechanic replaced the valve cover and timing belt again. I had him do a compression and leak down test on the motor which he says passed. Later on after I had these problems is when I added the exhaust. and about a week after that I got the CEl for the first time, so I thought it had to do with the lack of the O2 and thats when i had him drill the pipe and put an O2 in. A few weeks after that I made a road trip from Gainesvill, Fl to Dallas, Tx. the car did ok (Even with the CEL on) on the ride down. On the way back, Ii'm not really sure where it happened somewhere late in the trip maybe around Tallehassee, the "key" that holds the crank in place broke so needless to say my timing was way off (I couldn't tell because I was asleep at the wheel after 10 hrs+ of driving) So, I took it back to the mechanic and he hooked up a machine to it and told me its ok. He then had me take on the highway to test it to see how it did after he adjusted the timing a little. Well, never in my life have I seen a car decelerate on a 1/2 degree uphill incline @ about 90 MPH in a low gear. Anyway thats when I took it back and he took it apart and found the busted key. Ever since then the car hasn't really ran very well and has progressivly gotten worse. Since then I have done a compression test and it did check out OK.

I'm going to test the O2 sensors this weekend and see if those are causing a failure of sorts (Original sensors) after that I'm at my wits end and have no idea where to go with this problem. I'm not that far away from just biding my time with this motor until it goes and then buying a new motor to put in; but I would like to figure out what is causing these problems.

(On a side note: I have spoken with the guys at FM and they are very nice. I have since then purchased a Hydra from them per their recommendation. I don't really want to put it on just yet unless I can determine that it is the O2 sensor causing the problem. I don't want to foul-out the $300+ wideband O2.

Well, any thoughts on this would be appreciated.

[POS Racing]

Have you confirmed the timing belt is installed correctly??

If it's a tooth off it will run crappy.

[MiataMike]

Have you confirmed the timing belt is installed correctly??

If it's a tooth off it will run crappy.

No that is on the list of things to check.

[icepenguin66]

Wow! You wouldn't mind letting us know who the mechanic is to prevent anyone else going to him?

What did he say about the broken key and how the hell did that happen since he did the timing belt? If the pulley came loose enough to break the key then it most likely damaged the groove in the crankshaft end, which is why I recently replaced a crankshaft.

How much oil was lost from the cam cover not being attached? If you lost enough oil you may have damage to other internal parts; probably didn't loose that much oil but worth asking.

[POS Racing]

No that is on the list of things to check.

I'd move it up to #1 on your list, sure sounds like your mechanic could up a wet dream......

Let us know what ya find.

[MiataMike]

I'd move it up to #1 on your list, sure sounds like your mechanic could up a wet dream......

Let us know what ya find.

Well, you guys wouldn't have to worry about the mechanic unless you plan on moving to Florida (nothing but put-heads live in Florida BTW) o_0

And enough oil was lost to cause the oil pressure gauge to move down to 0 when turning a corner.

Well, sadly to say the mechanic is not the only person to work on my car and mess it up. As a matter of fact everyperson that has ever touched my car has done something to mess it up. That even goes back to having the car 4 or 5 months and taking it to the dealer (pretty close to 10K in actual damage. And that was a Dallas, Tx Dealership, which is no longer in business)

[POS Racing]

Ya ever talked with Steven Boyd at Miata Solutions?? He is the best there is in this part of the world.

Sure sounds like a timing issue, you mention your mechanic in Fla. adjusted the timing which is quite a trick since you cannot adjust the timing on NB without having to do some specialized "rigging" since the factory doesn't offer any way to adjust the timing.

FYI - The Miata shop in Dallas sounds like he may be related to your mechanic in Florida.

[POS Racing]

3. (No cats)

Which will give ya a P0420 (Catalyst efficiency below threshold) since there is no difference detected between the 02 sensors. Ya got something in place to fake out the computer since the cat is MIA???

[MiataMike]

Which will give ya a P0420 (Catalyst efficiency below threshold) since there is no difference detected between the 02 sensors. Ya got something in place to fake out the computer since the cat is MIA???

Thats what the Hydra II is for

[POS Racing]

Thats what the Hydra II is for

Wouldn't an O2 simulator be considerably cheaper??

No emissions testing in Florida??

Have you checked the timing?? Does it show to be good??

[MiataMike]

Well, I already have the Hydra I just need to install it.

And there is no State Inspection in Florida (I'm not worried about it in Texas either)

I haven't been able to check the timing belt or anything to do with the timing. I don't have a timing gun anymore.

[sammm]

I haven't been able to check the timing belt or anything to do with the timing. I don't have a timing gun anymore.

You should be able to find something on Miata.net about counting the number of 'exposed' teeth on the timing belt and the position of the cam gears.

[channelmaniac]

On the left the I marking is straight up and on the right the E mark is straight up... They may have to tilt just a little to the side to get the belt lined up right... count 19 tits of the belt between the gears... just like in the picture...

[MiataMike]

Well, i have tested the O2 sensor, and it seems to be OK.
The next thing I'm going to look at is the timing belt to see if its skipped a tooth

[channelmaniac]

Well, i have tested the O2 sensor, and it seems to be OK.
The next thing I'm going to look at is the timing belt to see if its skipped a tooth

Just make sure you DO NOT go by the I or the E spoke but rather the little mark that is cut on the side of the edge where the belt lays on the gear. You want the 19 teeth to be between those marks. It's hard to see those marks from the picture.

RJ

[MiataMike]

Just make sure you DO NOT go by the I or the E spoke but rather the little mark that is cut on the side of the edge where the belt lays on the gear. You want the 19 teeth to be between those marks. It's hard to see those marks from the picture.

RJ

I'm not sure when I'm going to be able to get to that. Is there anything else that you know of that could cause any of these problems?

Also do you know what the torque settings for the valve cover is supossed to be? (I ordered a shop manual but I haven't gotten it yet, <Its on backorder>) =-\ thats what I get for being so stingy and not wanting to pay $150 bucks for a book now that I need one

[MiataMike]

Also I forgot to add:

I did pull the hose off of the booster sensor and put it on the blocked port ontop of the throttle body. It had no effect on the system at all. Both spots had good suction which leads me to believe I did clean out the EGR ports well enough.

[sammm]

do you know what the torque settings for the valve cover is supossed to be?

http://www.miata.net/garage/valvecover/index.html

[MiataMike]

Well, I just didn't have the time or the tools to do any of that stuff to my car, I just decided to take it to a mechanic. After a phone call with him today after he tore the valve cover off and inspected the alignment of the timing belt this is what he found. The Crank pulley bolt was loose, and when he tried to tighten it the bolt would just spin, so he took apart the cover where the crank is to find that a bolt inside wasn't tightened and it was causing the timing to retard 20 degrees or whatever the max is. I found this article (Even though its fan an NA) tell me what you think..

http://www.miata.net/garage/crankshaft.html

[channelmaniac]

Uh.... if the crank bolt wasn't tightened up then you probably have some severe damage to the end of the crankshaft.