Wow. So it idles at 750 now? That's right where it should be. You probably need to adjust the throttle position sensor now. Use a multimeter and check the voltage (to ground) of the green/red wire at the TPS. While running, turn the screw until the voltage reads 1.00 volts. Rev, check, repeat.

Also, you did jumper the initial set coupler when you set the timing, right? That locks in the base timing so you can actually dial the timing to the correct position. It's essentially telling the ECU to not account for load changes when you jumper it.

You don't need to open the top of the CAS to see if the timing is jumping around. Putting the timing light on the pulley does the same thing.

Other possible issues you may have:

-bad grounds (nightmare, but there's a good writeup about that on aaroncake.net) http://www.aaroncake.net/RX-7/grounding.htm
-MAP sensor (Mazda calls it something else, let's just face the fact that the rest of the world calls it a MAP sensor)
-AFM (check to see if the flapper door opens smoothly without any hangups)
-coil/ignitor (see if you're getting good spark to all 4 spark plugs, and check the spark plugs while you're at it. Should be 2x BUR7EQ and 2x BUR9EQ)

 

have you checked compression?

 

sorry for the late post. busy with school but i change out the fuel filter since it was cheap but barely changed anything but i accidentally forgot to tighten the CAS nut and my timing moved but when i got it back within timing using the timing light it was still acting as it would do and hesitate but when decided to see if i could smooth it out by feel instead of using the light and when i turned it clockwise all the way i could rev it and it would barely hesitate. i think it can be off because i had FD housings installed with the build. dont they have spark plug holes a little lower than FC housings? and if they are lower i cant get it in timing because it set to spark where the spark plugs are supposed to be (but are not)? let me know if i sound stupid. this was a trial and error move i made but it made it run better lol

 

no one knows? ill make a video tomorrow and try to see if there is anything else i can change to fix it. its almost where i can drive it i think

 

ok so i was right. i took some of the metal off on the CAS so i can adjust it even farther and it runs good now. just need to get a couple things (new plugs, headlight bulb, air filter) before i drive it around.

 

could the cas be a tooth off?

 

the CAS was not a tooth off. i tried multiple times and got the same result i even made it a tooth off to see if it runs better and it didnt. im messing around with the idle adjusting screws to get the idle right. its barely got a hesitation now but i think its might be because its running a tad too rich.

 

I bet that the timing marks are wrong now and that is why it runs like crap with the timing 'set" and runs better with the timing "turned randomly".

This is something most people don't know, but...

1) if you install the worm gear that drives the CAS backwards when you build the engine/stack the front cover parts, the engine will run fine however the timing will be about 3-5 degrees off from correct.

2) if you swap EITHER the front hub OR the pulley with the timing marks on it, the timing marks will no longer be correct. This means you'll either have to manually find correct leading timing, or locate and swap on a pulley/hub set that were originally mated to one another and have never been separated.

 

i just found one of the vacuum hoses is broken and going to replace it. its the one that goes to the blue vacuum solenoid. which if im right its the relief solenoid valve. but here is a video showing the hesitation. the car doesnt die on me if i lower the idle but i had to go to school so didnt have too much time to mess with it.

 

car is warmed up by the way. have to find the wire and i dont have a jack to get under the car yet to find it.

 

ok so the car is running alot better. i blocked off all of the emissions with the kit banzai racing sells. i messed with the timing a little bit but have not gotten it quite right. is there any trick that someone might know that can help me time it. if it get it to where the engine is really smooth it has the hesitation between 2.5k and 4k. if i advance it it isnt as smooth at idle but the hesitation lessens. im going to play around a bit more but will the split time with the timing have changed from a n/a s4 to fd rotor housings? and if that could be causing it, how can i fix that?

 

No it won't effect how the car runs, lots a of people use FD housings.

My friend had a similar problem and it turned out to be his fuel pump wiring. But this was on a T2 with the 9volt cruise 12volt high load thing.

I'll see if I can find the thread. It may or may not help.


Edit: dunno if this would help

https://www.rx7club.com/2nd-generati...tutter-996879/

https://www.rx7club.com/2nd-generati...3800-a-994179/


Triple Edit, this one has a video of his hesitation.

https://www.rx7club.com/2nd-generati...adings-997751/

 

i will try and test out my fuel pump and wires. havent looked into that. replaced the fuel filter front and back and blocked off all of my emissions. even deleted my omp, even tried my other three MAF. replaced my injector o-rings (the bottom ones) and all helped the car a little bit but like i said still have a small hesitation that i can feel and i know its not completely right. my car is an n/a by the way.

 

Just to make sure, your premixing now correct?

 

i read for n/a it should be a 2oz per 1 gallon? but i would put in a little bit more per gallon. am i right?

 

ive been using valvoline tcw3 2cylce 2oz per gallon of gas. too much 2stroke?

 

1oz per gallon NA or Turbo.


Edit: I use the vavoline as well, blue bottle right?

 

yup blue bottle. and now i know to go easy on the 2stroke a little bit lol.