Ok I have looked at so many threads about the common 3k and ugly 5-6k hesatation. Correct me if I am wrong but I have yet to see a thread on getting rid of the ugly 5-6k hesatation. Either people just give up or the dont post that they got it fixed. I have found many on fixing the 3k problem I fixed mine by just cleaning my aux ports. I am now in the process of fixing my 5-6k problem. Ok first off all the things I am trying are with only like a gallon two at most in my tank. I have seen some posts that state this problem only happends when the have a quarter of a tank or less. All I have done so far to try and fix it was replacing grounds such as neg on batt,and tranny to firewall. Here is a list I have come up with of things I am going to check from reading all the threads out there. swap ECU,reset ecu, try adding another ground from engine to neg batt, change fuel filter,regroung ecu in car,reground boost sensor,check for rust in gas tank,check fuel filter inside gas tank alone for clogs in fuel lines,I have seen rumors of the exhaust ground fixing this problem but im sure its bs but I will replace it anyway because mine was ripped off,check secondares with meter maby send off to be cleaned. Please add anything else I missed to check but I hope I fix the problem befor I reach the bottom of my list. I know that all cars are different along with mods and may have different causes to this problem than mine. This problem is just driving me crazy so I just wanted to let you all with this problem to know what I have found out if you have yet to fix it. Has enyone been sucessful in fixing there 5-6k problem if so please let me in on what you did. Anyway I am going to try these things out and hopefully I will get it fixed and let yall know what works or not.

 

I'm having an intermittent one right now. I've tried just about everything you have said except the 5th and 6th port thing because I have a turbo. Only thing I can tell you is that wayne88n/a does not think adding grounds is such a hot idea because it actually confuses the ecu. He said the best thing to do is just clean the existing grounds and add one ground from block to chassis if needed.

 

No, don't ADD an additional ground from block to anything. If you think your OEM ground is shot, you can add a new one from eng to battery, or whatever, but then you need to remove the old one...I highly recommend just "cleaning up" your existing grounds, and if the harness is obviously bad, replace the wiring run, but use the same electrical pathways that the Mazda engineers designed into the car- they obviously worked when new...

Nates- if you can feel the secondaries kicking in at about 3800, and you know that your 5th/6th ports are good, then your problem is electrical. Maybe a weak ground, a weak ignition system, a boost sensor or AFM that's hitting a "dead spot" so that the signals are interrupted at the ECU, etc...

A very good way to troubleshoot this problem would be to get to the ECU, and read out suspect sensors while driving. Just don't hit anything while looking at the meter

 

Here ya go...

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/troubleshooting-your-car-ecu-340578/

 

Ok thanks I did not find that thread ill give that a try first. O and I was taking a look under the UIM and I think my rear rotor housing ground was moved. I could see a elevated bolt hole with nothing in it. Then rigth next to that there was a ground placed on a bolt that holds the bracket that connects to the dynamic chamber. Was that the oem spot or am I missing something. O while I am at it one little question I had set my Idle to like 800 because I was sitting at 1000. Well after driving hard when I rev it up a little and let off the rpms drop so low that the shift light and evrthing comes on like if about to stall but then it rises back up to 800. Did I set it a little to low or something?

 

Yeh, the OEM spot was on top of the rat's nest bracket metal, with the 12mm bolt on it... Not a very pretty arrangement, because two surfaces need to remain very clean for the ground to function properly (housing-to-bracket, then bracket-to-ground terminal). But, I still use that ground location to this day, I just "clean it up" every time I've got the UIM off...

You might have set the mechanical idle adjust too low, and your BAC is struggling to pull it back up to 750-ish...

 

O I have the bac removed and blocked off

 

That shouldn't have anything to do with a 5-6K hesitation...

 

I was talking about the droping idle when you said this. "You might have set the mechanical idle adjust too low, and your BAC is struggling to pull it back up to 750-ish..."

 

In that case, it's funky that your idle is coming up at all, then...Unless your air bypass solenoid is kicking in- or did you remove that too?

 

No should this be removed? I turned the idle up a tab now thats ok i guess still drop a little but not as bad. As for the 6k hesatation I fixed it I dont know what it was that fixed it because I did three things. I added another ground from the neg batt to the dynamic chamber bracket behind the alt then to the firewall. Was there a stock ground from the block to the firewall or neg batt? If so I have good reason to believe it was messed with due to what I found in stock grounding spots.I sanded the paint away on the firewall for the tranny to firewall ground. Also did the same for the new ground I added. I also reset my ECU but I have a question. My ECU had mapping changes so would reseting the ECU clear those changes?

 

According to a particular guru on this forum, the S4 ECU's cannot be reset, and cannot "learn". I disagree with this, especially the "learning" part, because of things that have happened with my car over the years, but I have no proof one way or the other...

In any case, no, do not remove your air bypass solenoid valve, especially if you have A/C and power steering. That valve allows the extra intake air necessary when these "high-load" systems are on.

If you're running fine now, leave your new ground alone, unless it creates more unusual "gremlins". Your OEM ground must have been in pretty bad shape, then. If you want, at this point, you can even remove the OEM ground from the rear rotor housing spot, as your ECU has obviously found a better path for its grounds with the new one, if she's running better now...

Drive the car for a while, and you should notice performance becoming "smoother" as the ECU "adapts" to the new grounding path. I've noticed similar improvements on mine after a couple of days, after certain items were changed, or "messed with"...