pp13bnos

iTrader: (1)

Last night/today i pulled the lower intake off of my car to throw in the new style pineapple sleeves (i had some proto-types) and port the lower manifold. I also finished doing the TB mod to my TB. Basically getting rid of all the crap on the side of the TB itself. But anyways i put everything back together, and took it for a spin. What i noticed is 1) the car needs to have the tps adjusted again, becuase i removed it when playing with the TB. 2) Car runs *Hard* in 2nd 3rd etc. In first though, you nail it at about 2k, the thing comes on hard....then at about 5,500 to 6k rpms the car seems to lay out, then couple hunderd rpms later, the car starts pulling like mad again. Does anyone have any thoughts on this? Just kinda funny that the car only has this problem in first gear. thanks, CJ

vaughnc

I'm surprise you even notice 1st gear problems (since 1st only lasts 1.5 seconds). So you slip it @ 4500 rpms and it bogs around 6500?

Problem doesn't go away after the car warms up / 15min of driving?

tesla042

I've been sorta noticing something simmilar.. It seems that 2nd pulls just as hard, if not harder, than 1st.. No launching or anything, just from a stop..

Then again, it may just be that i'm in 2nd a good bit longer than 1st, so it's my mind playing tricks on me.. but my passenger said the same thing.

-Tesla

mazdaspeed7

When I was having the redline hesitation problems before, it was always worse in 1st than any other gear. I dont have any definitive answers for you, but I would check your mixture(O2 sensor voltage) and timing. Definately set your TPS before you start worrying about the other things though. My hesitation was much worse with the TPS a little out of adjustment.

pp13bnos

iTrader: (1)

Well i got a chance to put some more miles on it tonight. Its not just in first. Its in whatever gear, you nail it in. But the gear after that is just fine. So, say i nailed it in second...there would be a hesitation. But once into 3rd it would pull just fine.

I'm going to put new plugs in it tomorow, (old ones have 4k or so miles) the adjust the tps, then take a peak at the timing. I'm also going to throw the mixture meter back to give me a rought idea of whats going on.

The only time i drive my car hard is when it is fully warmed up.

Hey adam, you once gave me a little diagram to adjust tps via ohm meter. Could you put it up again? Later, CJ

mazdaspeed7

I never posted a chart or whatever, but I do know the best way to adjust it.

Bend a paperclip so that you have an inch or so sticking straight out(you will need 2 these). Push it into the back of the TPS connector on the top and bottom pins on one side, that the wires to to the narrow range TPS(sorry, but I cant rebember which side they are on, mine got turned around alot.) With the car idling, measure the voltage between those to wires via the paperclips shoved into the back of the plug. Adjust it until you see 1V at idle.

It sounds like a bad mixture, probably from the TPS. Adjust the TPS, then worry about other things. One mor ething, make sure the engine is fully warm before you adjust it, go drive for 30 min or so, then adjust it while the engines hot.

Bambam7

Sounds like a bad ECU- I'll have one in a week that I can sell you for 100 bucks!

Just kidding, You mentioned that you ported your lower manifold right?
There seems to be SEVERAL of us that have had probs experiencing high RPM hesitations after porting theirs... Gees... I REALLY hope that there is something else related. I don't want to think that reversion waves/ velocity were so finely tuned with the stock intake that they cause bad high performance when the volume is modified... I REALLY HOPE!!

I am also developing a stutter. It happens for a split second at about 6300, goes away/revs strong, then again for a split second at 7500, then fine up to 8500. Everywhere else is fine, and the o2 voltage is steady at about .89v
It's NOT ignition, otherwise the o2 voltage would spike up.

mazdaspeed7

My hesitation is gone, completely. My powerband is smooth and even, from 2K to rev limiter at 8800.

The hesitation on my car was mixture related. I put the stock fuel system back on(had TII pump and secondaries) and took my Hi-6 off and reset the timing(still advanced,but not as much as before). Now my car runs better than EVER before. Ill be dynoing again once I get my exhaust redone, prob in a month or so.

Bambam7

Mazdaspeed7- Something just doesn't make sense with what you're describing...
OK- I believe your high rpm prob was a result of leanout- if you were reading o2 voltage down to .70's. It makes more sense than ignition.
So- why the hell were you leaning out with a TII fuel system???
Even stranger- why would your car be better now after putting in the stock injectors and fuel pump?
There is ONLY ONE solution that makes sense to me here, and I'm suprised nobody else has mentioned it yet, but I definately think you just had an injector problem.
Either a bad connection, or a dirty/defective injector(s).
Your fuel pump could have been bad too... shoud have checked fuel pressure.
Fuel injector prob matches all the symptoms.
Since the o2 sensor measures hydrocarbons, if an injector was bad, and just squirting in inadequate amount of fuel, and also, toatlly unatomized, some raw fuel would be going through the exhaust at higher rpms (I know, even though it isn't flowing enough gas, if it isn't atomized, it won't completely combust) And giving you a voltage that is even higher than it should be. Your .75, which is low to begin with, would hypothetically be more like .6!
I bet if you check your o2 voltage now, it will be higher.
I also bet that if you get those injectors cleaned, you will be fine!
This is the only thing that makes sense to me, and the simplest solution that satisfies ALL the variables! (Basis for a good hypothesis!)
Good luck.
Dan

pp13bnos

iTrader: (1)

Ok guys, put some plugs in it. Old ones were not bad, but not great either. Adjusted the tps, and put the mixture meter in. The car runs better, but not perfect.

On my air/fuel meter, it reads two bars green until about 6-6,500, then it starts to show 3-4 bars yellow, and one still green. It holds this all the way to redline.

The car does idle better than it ever has. For awhile, if you came upto a stop, the car would idle at 750 or so...then miss pretty bad for about 2 seconds. Idle would come up, after that for a about 4-6 seconds, then repeat. That problem is all gone

After i went out and beat on it some more, i backed the timing off a couple degrees. Not real change, but it did'nt feel nearly so responsive.

When i bought the car, there was a check valve right before the fuel filter. I'm thinking i'm going to remove it tomorow, and see if that clears anything up. The reason why it has a check valve is because the stock pump would'nt hold pressure once shut off. So everytime you shut the car off.....it would be hard to start. The previous owners way of fixing a leaky fuel pump

After that...i guess i'll have to get anouther o2 censor to put in the other side of the exaust. Just to see if the rear rotor is running as well as the front. I'll just put a switch between the two for my mixture meter. That way i can switch between the front or rear rotor, with a flick of the switch.

If anyone else has anymore input...feel free to share.

Later, CJ

pp13bnos

iTrader: (1)

Ok, removed the check valve, and reset the ecu. The test spin seemed no different than any other. Still missing. So, i swaped out my secondary injectors for some ones that have'nt been cleaned. Then it was down on power, and missing alot more, through out the power band.

So...i'm starting to think maybe i need some bigger injectors and a afc(?)

So how much does a set of 550s usually run? Someone has to know. CJ

pp13bnos

iTrader: (1)

Hey bambam, if the ecu does'nt do anything for you, don't feel obligated to buy it.....I like having a spare around to be able to throw into the car in times like these. CJ

Bambam7

You have an A/F meter don't you? You should be able to see if you're leaning out...
Don't worry, if the ECU does nothing, I'll send it back with a check for shipping
Thanks again!

pp13bnos

iTrader: (1)

The car seems to run better when its cold.....anyone got any ideas now? Also does it matter to what position the mass air meter is angled. Mine is facing about 45 degrees downwards. Any more advice? CJ

mazdaspeed7

It sounds fuel related, possibly from a faulty temp sensor. Check the coolant temp sensors on the water pump and ont he block under the oil filter, and the intake air temp sensor on the intake manifold right below where the flange for the throttle cable bolts to the intake4 manifold.

Faulty temp sensors can throw off your mixture, which WILL cause stumbling/low power, etc. The coolant temp sensors have a suprising influence on the mixture.

BLUE TII

iTrader: (9)

Yes. I have heard the angle can cause the AFM flapper door to swing open too much and cause rich running, which would have less affect when the air is cold and more dense. Ram air systems have the same affect on AFM at surprisingly low speeds.

pp13bnos

iTrader: (1)

I don;t have the door kind, but i'll check it out tomorow.

Adam, how does one go about checking the different sensors? CJ

mazdaspeed7

You check the resistance when the sensor is a know temperature. Most service manuals have more details on it. If you want, Ill look it up and post it.

mazdaspeed7

Well, mine is back, and more obnoxious than ever. I recently went back to 87 octane, and set my advance accordingly. Heres what I noticed. 87 octane, no advance on the timing. Low end and midrange felt more sluggish, and it felt like I was hitting a wall from 7K-8K, where it would get a surge of power for a min, then drop off again. It is so bad I can barely accelerate from 7K to 8500 in 2nd gear. Then I advanced the timing some, still conservative enough for 87 octane. Low end and midrange were back to normal, the top end was not hesitating, but it wasnt like hitting a wall before. The car would still accelerate, but was hesitating pretty bad.

The same went for 89 octane, but the timing could be advanced more, and the hesitation was not as bad.

I dont see how it could be octane related, but advancing the timing making it better. So I need to find something more likely. Any thoughts on the cause? The plugs are good, as are the wires.

How long of a life should I expect out of a fuel filter when running full premix(1 oz/gallon)? Mine was replaced ~14k miles ago.

pp13bnos

iTrader: (1)

To be honest, i never realy did figure out the real problem my car was having. After i had it dyno'd, i figured out it was running way rich, so then i installed a s-afc, and fixed the problem. I know, you're selling your car, so buying a s-afc is out of the question. But if you could find someone to let you borrow one for an afternoon, i bet you would be able to get that thing to rip again. CJ

mazdaspeed7

Actually, Im leaning towards keeping it. I havent had any serious inquiries. Besides, the car is very close to being right. I have already fixed most of the problems that made me want to sell it. I dont think Im going to waste money with the S-afc. Im looking to go Haltech later this summer, if everything goes well. I plan on giving the motor a very mean port job in a month or two, and Ill have my new exhaust finished and on within 2 weeks.

Im starting to think its running to rich also. Im getting .89V on the O2 sensor since I put the TII pump back in. My n/a fual pump crapped out on me, and the only one I had around was the old TII one. I still think the car ran better with the n/a pump. I think Im going to mess around with the AFM some, like add a small resistor to the signal lead to try and lean my car out some.