niteshade247

Ok I'll start with what it's not I just did a full ignition replace BHR. It's not compression never flooded no hot start problem lots of power no symptoms of bad compression at all. No cat so it's not a clogged cat. Only CEL's showing are O2 and secondary air pump. Pump is due to it being removed as I did this because there is no cat. It's not a dirty throttle body I just cleaned it.

Now to what it's doing. Under 2700RPM it bucks and kicks and some times (just started this) it's lagy till I hits 3500RPM and then it's a big explosion of power. If I hold my foot just right going down a hill or on a flat area I can feel it trying to engage and disengage the throttle not as bad as under 2700 mark but noticeable.

Now for what I think it could be. I have had this happen to a nother car and it ended up being a bad TPS as it was not reading correctly the cars ECU would receive bad info and could not ajust fuel correctly. Or I'm thinking I need to clean my fuel pump sock filter as it's never been done as far as I know and the car is at 140k. Any other suggestion are wellcome. I'm planing on pulling the fuel filter this weekend. Or could it be a sticking valve be for I started doing me own maintenance mazda would over fill her and I had to clean the intake out several times.

I was wondering if the TPS was built into the throttle control unit as I can't seem to locate it.

RIWWP

iTrader: (2)

You flow more fuel at high power than at low power, so a filter clog wouldn't really produce that set of symptoms.

I have only rarely see a throttle body related problem, so I tend to discount that. Keep in mind that our throttles are completely electronic. Your foot commands a throttle %, and the ECU then makes that happen, or intercepts it if it sees a reason to be in limp mode.

Assuming that I take your description at face value, a sticking intake valve would seem to make sense to me. However, of the 4 valves, the lowest one opens at 3,750, so all of them are closed around the time of your transition, and "sticking" should manifest higher.

SSV: 3,750
VFAD: 5,500
APV: 6,250
VIV: 7,250

I don't have the numbers for the valves for a 4-port engine, I forget which you have.



However, our engines are so gutless under 3,000rpm anyway, that I am not sure if you are really feeling a problem here or if you are just feeling the nature of the engine.

niteshade247

Well all valves are opening then because right around the 37 mark is the first power berst I feel. It could be the nature of the best and just started to notice this because of the application of the new BHR ignition as the old one was almost 60k and no change. It just troubled me because of the feel when going down hill or on a flat area and it only does this when I have control not under the cruse. The more prevalent times is when I forget to down shift and the RPM is realy low in that gear it will lerch and jerk till I let off and down shift unless in first gear the I just let off and ease back on.

I have the 6 port 2004 MT.

RIWWP

iTrader: (2)

Yeah, I wouldn't worry about it. The engine really doesn't like being under 3,000rpm in gear naturally. If you get really concerned, find someone else's 8 to drive and see if it feels the same. Otherwise, just keep it above 3k

kevinande

You could put the old coils back on and see if you get the same sensation?

niteshade247

That's ok I'll deal with it and if a cop pulls me over I'll just tell him RIWWP told me to keep it above 3k RPM I'll even mail him the ticket

RIWWP

iTrader: (2)

Why would you get pulled over for >3,000rpm?

3,000rpm in each gear is roughly:
1st: 13mph
2nd: 20mph
3rd: 31mph
4th: 40mph
5th: 46mph
6th: 62mph

Hardly illegal speeds...

It's one of the advantages of the rotary, you can keep the RPMs up by just being in a gear lower than you were, and you can pick any one of 3-4 gears for any given speed and it's viable to use.

niteshade247

It was a bad attempt at a joke I'll just mail you the really big tickets