Ok before I give the story about the problem about the car, everyone should be aware that this car has completely removed 5/6 ports/sleeves and a ported throttle body/throttle body mod, along with a streetported motor with about 15k-20k on a fresh rebuild, all emissions removed (no airpump) also has full exhaust with no cat (str8 pipe) incase thats important...also believe the brake master cylinder is going, but I dont think it would cause this problem


The car drives all the way up to redline under load, I'm just almost sure something is definitely not right if its doing what it is.

Just revently when I first start my car up and even after its warmed up, if I quickly press the gas pedal the car will bog out and not rev up, i think its causing a big time power loss , especially between gear shifts...but I'm not sure, but anytime I press the pedal fast all the way down the floor it bogs out completely, but it doesnt so much where it will make the car stall out and stop running.

Im not sure if it could be -

1. Bad Maf
2. Intake Leak(s)
3. Exhaust leak(s)
4. Throttle body sticking/cable problem
5. Bad Throttle Position Sensor

If anyone has had this problem before or if anyone even has any idea as to what it could be let me know.

 

all i'm thinking now is that since you eliminated the sleeves, your low end is way worse. but i dont know about the bogging... more diagnosing to do i suppose.

how's the climb to redline on the road?

 

clogged fuel filter or fuel pump?

 

It gets up to the redline just fine, but the last time I tried to get it to chirp/spin into 2nd gear going uphill it just felt really weak, like anyime the car goes from no load to full load very quickly, there is power loss and it should have enough ***** to chirp/spin 2nd with ease.

 

This sounds like it could be the problem, ive replace the fuel filter, but since replacing the car has run out of gas or even ran low several times (i mean like close to 10) ,

i know ya'll are gonna wanna cuss me out for driving on a low tank with no gas so many times , but I really havent had much choice...this car is my love but I just dont have the money to give it all the tlc and gas I'd like to.

How could you fix and or diagnose this as being the problem?

 

TPS problem? Try adjusting it. Look in the FSM for a "how to".

A poorly tuned TPS will cause bucking, bogging, and poor idling etc.

 

Ive actually had it tested/set before by a very good rotary mechanic not that long ago, and when it actual wasnt working properly it was causing my car to backfire anytime i let off the throttle.. I just thought maybe it was a possibility this could be causing the problem because on an rx7 you really never know what it could be until you actually troubleshoot with process of elmination of possibilities.

I am going to check out the fuel pump sock tommorow, after hearing what jdm just told me about his friends car having a similar problem because of a clogged fuel sock it makes me almost certain thats what the problem with my car is...we'll see tommorow...if that fixes the problem great , if not I'll go from there to replacing the fuel filter and onto everything else I can think of (leaks, tps etc)

 

Backfires are usually caused by leaning out the AF ratio. It could very well be a fuel issue.

 

im having the same problem and dont know what its

 

Took out the fuel pump today, the filter on it was clean and looked practically like new, but there were some rust flakes/chunks in the reserve in the tank but I know thats not whats causing the problem because the fuel filter on the pump was very clean.

The only other thing I can think of is that the actual fuel filter could be clogged ? But I dont understand how that would get clogged if the fuel pump isnt, especially when Ive already replaced the fuel filter once, but the only way to rule it out as the cause of the problem is to replace it.

Anyone else have any ideas feel free.

Also the backfire issue in my car that was caused by the tps was due to a bad connection on the tps (diagnosed by test light by my friend), which means it wasn't working and/or working intermittently.

I had a very nice friend of mine fix the connections on it and put some new wiring on it and it's been working fine since.. he also adjusted/set the tps for me, so I wouldnt think the tps could be far off now, and even if it was I doubt it would cause this much of a problem..

Unless.... the tps can do things I dont know about yet while it is functional.

 

You modified the throttle body right?
If you suddenly go from part throttle to full throttle, it will bog now. Thats part of the compromise.
You should just learn to drive smooth and roll onto the throttle. Chirping 2nd gear is only cool until you lose your second gear syncros

 

Yeah man ,my throttle body is ported like to the max dude. I guess I never really noticed the boggishness under fast full throttle, i didnt think it was suppose to be this noticable, I always thought it was more subtle.

I was thinking of actually going and replacing the throttlebody and/or intake and seeing how much difference it makes with a stock s4 intake or even a s5 na intake if that would make a bigger performance difference.

Oh and as far as rolling onto the throttle, I know howto do that it just seems unsmooth at low throttle (little hesitations and such), i donno if 5/6 ports or the modded throttle body are most at fault.

I might replace the tb first because its obviously the easier job.

 

Before you replace the TB, check the TPS one more time. Because you had it check a while ago, doesnt mean it's still in check now. Its pretty easy to check if you have a multi-meter. Out of adjustment TPSs can cause all kinds of weird symptoms. Right now, my TPS is shot and has a dead spot in the throttle range. Part throttle and full throttle are fine, but anything in between buck and fart like crazy.

I just think its something worth checking before you swap in another TB.

 

I'll have to figure out how to do it because I'm not that good with the electronic stuff , my friend when he did it with a test light by pulling the throttle opened and adjusting it until the test light stayed solid when he turned the throttle opened.

I dont have a multi-meter but maybe if I can ask him how to use the test light method or even find out online I'll try to readjust it myself and see how far off it is , maybe that will make a difference.

I honestly dont know really what I am doing when it comes to tuning the tps/timing etc , havent really had much experience with that.

 

the 5/6th sleeve removal and t/b removal are both at fault, either one of these is going to make you lose power in the bottom end, you just need to be smoother on the gas as someone previously said, i wired my 5/6th's open and it made a small loss down low but the t/b mod had even more of an effect. switching t/b's is a quick job obviously not as quick as the tps but you should get some of your bottom end power back

 

Here is a link for how to adjust the TPS. This page is for a TII car, but the process is the same, the TPS is just upside down. I bought a multi-meter for $3 at Harbor Freight. You get what you pay for, but it works well enough to test stuff like this.

http://fc3spro.com/TECH/HOWTO/TPS/tps.html

 

My TB is ported/modified and I have no problems.

BTW, everyone always says they have rust chunks in the bottom of their tanks... That is actually varnished gasoline. I bet that is your problem (or it doesn't help much anyway). Your baffle holes could be clogged with varnish. If you let it sit for a minute or at light throttle it will be able to pull what it needs into the main pump baffle. When you slam the throttle it very quickly sucks up all of the fuel stored in the baffle and then simply runs out.

Remove the pump again, (wearing some thick vinyl gloves) pull, scrape, peel, or whatever you have to do to get the varnish out of the baffles. I bet you it's clogging the "fill holes".

 

Bump for same problem...

new tps
fuel pump, filter
cleaned tank

 

im all for doing a full test on the tps and connection.
i dont think its a fuel problem. there should be enough residual pressure and fuel in the fuel lines to compensate for the immediate rush of air at least enough to resist bogging right away.