86RX7FC

So Ill start by saying my car is an 86 S4 FC N/A

So I have multiple things going on with my car. Its a fresh rebuit engine and I have flooding issues which can be solved by pulling the fuses and problem solved but its getting worse but I can solve it with pulling the fuses and the leading plugs. It will start but sounds like its still flooded and will die moments after it starts. If I do this multiple time it will eventuall run and sounds like its flooded so i keep it up around 3k till its almost at operating temp and it eventually smooths out and will idle about somewhere around 1k. Ill warm it up and take it for a drive. I had let it run just the other day to go inside the gas station to pick up stuff and when i came out it suddenly just ran like crap like it was running on one rotor. I eventually got it to run decent by pluging the vac line located in the middle of the 3 on the front of the throttlebody and using the variable resistor on the pasenger side shock tower. Now the car runs ok After fighting it to get it started (planning on installing a fuel cut switch) I can push in the clutch and hit the gas and will rev over 4k but under load through all gears it starts to chug and sputter around 3k and it seems to hit a wall at 4k but it will pass 4k if im on the gas about 25% or less but slowly it will pass but when I try to press further on the peddle it will bog and chug again.

List of mods and new parts:
fresh rebuild
New fuel pump
New fuel filter
Went from 460cc injectors to new 480cc injectors
removed 5th and 6th port valves
block off plate on emision stuff on the lower intake manifold
removed 5th and 6th port valve actuators and sealed vac holes
water pump and alternator is the only thing using a belt
manual steering rack
no a/c
no air pump
pacesetter headders
no cats straight piped to an ebay can with silencer
replaced all vac lines
regrounded all grounds
rewraped all wires in engine bay repairing bad insulation on some wires
3k miles on rebuit TII trans
400 miles on rebuilt engine
10.2mm spark plug wires
relocated battery in sorage compartment behind passenger seat using 2ga wires
880cca battery
and maybe some other stuff i cant think of right now

so i did some research and couldnt find a deffinate answer on whats going on. the compression test shows 3 even bounces on both rotors around 60psi and about 80psi without depressing the releif valve. the pulsation dampener is still good (can hear and feel clicking). it gets good spark. alternator is good. starter is a good rebuilt starter. the tps is used, tested at 4.2k ohms at wide open and 1.04k ohms at idle. mass air flow meeter is used. o2 sensor is new. water pump temp sensor is new. no coolant leak and still smells like coolant. oil (20w-50) appears a little watery with an exhaust smell but not a smell like gas. no smoke from exhaust.
i think it might either be the tps, maf, or maybe something else. im just baffled at the flooding issue since i would like to turn the key and have it run instead of a fuel cut switch but i will do so if need be and the wall at 4k. oh and while im doing the break in i did not rev over 4k till around 370 miles but have never reved over 5k and still planning on breaking it in till 1,000 miles but driving with these issues is a bit of a nucance since its my daily driver.
I supose thats enough for now and Ill try to answer any questions to the best of my knowledge. oh and i only have a haynes manuel and no fsm so i would also like to know how to test the maf with a prefered method of using a multimeter.
thanks in advance for taking your time to read all this. i need help not insults.

SpeedOfLife

iTrader: (16)

Why did you go with 480cc injectors? It's not a huge jump, but probably won't help since these tend to run rich anyway.

80psi max compression? I'd hope after ~400 miles you'd be seeing better numbers... are you testing compression after it's been warmed up and the throttle open? Low compression will contribute to flooding startup problems. Also if you used less than ideal housings/reused apex seals then I guess that could keep compression down.

When you rebuilt it did you make sure you used the same main pulley hub, the one that has the timing marks? Apparently these varied a lot and if you used the wrong one and set your timing off of it it would run really poorly, if at all. I only ask because this happened to me, and it was a huge pain in the ***, boosting at 10% throttle and basically burning fuel in my turbocharger, it would glow bright orange.

There ought to be a copy of the FSM floating around. I keep hearing mention of it, but since I already have mine I haven't really looked for one. It should be out there somewhere.

86RX7FC

well I bought them on ebay and I was unable to find new 460cc injectors so I thought 480cc wasnt much and i knew they run rich but i tried to tell myself that it would help compensate for deleting the 5th and 6th port valves.
when i did the compression test it wasn't quite warmed up it was done about a half hour after turning it off but it was running for a few hours since i was adjusting this and that and took it out for a test drive and so on.
all the seals and springs are new except for the apex seals but they were within mazda specs using a mic. can't remember what they were though.
my old man (father) doesn't know much about rotarys but has been a mechanic since '72 and he said that by removing the valves you would get more air at low rpm but have lower vaccume pressure at low rpm. i did notice by pluging one of the vac lines the idle smoothed out. could the vaccume be the culprit of my issues. what is the purpose of the vac line that i plugged. it is the one that goes from the throttle body (the one thats just under the vac line for the oil injectors) to the lower intake manifold in between the pirmary fuel injectors.
the origional main pully was reused and the timing was set at about 1k - 1200 rpm.
i havent done much looking around for the fsm but im definately still doing research regarless. trying to figure it out before it gets to cold here in minnesota. have no garage so im doing it outdoors.

J5sense

iTrader: (3)

make sure you have your crank angle sensor stabbed right, on my mazda reman motor it took about a week aor 300 miles before the flooding stopped. its gonna be a bit longer with you with the bigger injectors.

check for vac. leaks. get a can of brake cleaner or carb spray and with the engine running burst spray around the intake manufold. if the idle jumps/stubles you have a leak. oh and the stuff your spraying is very flamiable. so dont catch your car on fire.

sounds like your compression sucks though,

SpeedOfLife

iTrader: (16)

Everyone says use brake or carb cleaner, I've had little success with that. It seems the stuff they sell around here isn't particularly flammable, but yes always use caution. I prefer this though if you have a compressor:
http://boostpro.net/prodtester.html
So you know, this is about the ONLY tool I regularly promote. It's not my site, it's simply one of the best tools to help you with your RX-7. When I first used mine I found about 6 or 7 leaks with it.

Also, I can't answer specifics about NA models. Turbo for life right here.

86RX7FC

so i was playing around with my car today and i tested the bac and the solenoid valve and they were both in specs. i also tested both leading coils and traling coils and both were in spec too. the spark plugs were pretty black so i cleaned them up using 360grit sand papper. i still had troubble getting it started but it sounded like it was running a little better around 3k - 3.5k but still hit a wall at 4k. when i got back to my place i played around with the air flow meeter while the car was idling. i pushed the flap in a little bit and the car reved up a bit and when i pushed the flap all the way in it killed the car. when i tried to start the car again it didnt seem to wand to start using the deflooding method but i didn't try too long. later today im going to pull the starter to get it tested to see if it even spins fast enough. but thats about as far as i got for now. how do you test the water temp sensor located near the thermo housing and what should the tolerance be. is my air flow meeter working proplerly, i think it might be.

satch

iTrader: (1)

The Water Thermosensor measures 2 to 3 volts at pin 2I (Green/White wire) of the ECU w/a cold engine and .4 volts fully warmed. The secondary injectors kick in at 3800 rpm and this might be your problem. If you can "slowly" increase the rpm from low to high then it's likely that the secondaries aren't kicking in when they should. You can trick the secondaries into thinking that the car is under proper load to signal them to kick in by disconnecting the Pressure sensor vacuum hose and plugging it in addition to unplugging the TPS and w/the car idling try reving it above the 4k level. This test can be done in the driveway.

86RX7FC

i can rev the car over 4k not under load but under load it wont. when i get up to 4k if im on the gas about 25% or less itll slowly climb higher and around 4200 - 4400 or something like that ill try to hit it and itll spit and sputter but when i slowly get it to about 5k and hit it itll take off like a bat out of hell. so it dosnt really like 4 - 5k range. it could be just something to do with the break in period. im about around 500 miles now and planning on changine the oil around 600 miles so i guess we will see what happens then i guess.

satch

iTrader: (1)

Sounds like the infamous "3800 rpm hesitation" where the car falls on its face as you try to punch the throttle when below 3800 rpm. If this is the case, then you need to reground the wires at the ECU such as pins 3A, 3G, 2C and 2R or you could you could try the quicker fix by adding an additional ground wire to the ground wire at the Pressure sensor.

86RX7FC

thats a good idea to try i know the '86s are notoriuos for wiring problems. i see the pins in my haynes but i dont understand regrounding 2c. i don't see a ground in that circuit. it looks like everything on it goes though the ecu.
with the other pins (3a, 3g, and 2r). should i just cut those wires and find a nearby bolt to use to ground them to the chassis or how would you reccomend regounding them.
what pressure sensor are you talking about? is it the one next to the variable resistor? it doesn't look like there is a ground on it looking in my haynes.
im just trying to be thourough.

satch

iTrader: (1)

Pin 2C provides a ground for six different sensors. The Pressure sensor, being one of them, is the sensor located near the Variable Resistor and it has four wires to it. W/key to on all of the wires will have some voltage to it except for the ground wire. One has 12 volts, one has 5 volts and the other one will have a couple of volts or so. If the ground wire at this sensor has an additional ground "added" to it then it is suggested by Mazda that it be grounded to the engine itself and not the body. And don't cut the wires at the ECU and ground them.

Aaron Cake

iTrader: (1)

The extra 20CC is just going to make everything richer.

And by removing the aux ports, you're going to make less HP than when they were functional.


Bingo. That's why compression is low. If they were put back in the same spot they were removed from, after about 1000-1500 miles compression will come up. If they weren't put back where they were removed, it will take a lot longer.

Since apex seals are the primary wear point of the engine, you should have replaced them.

I don't know what any of that means, but what you have done is reduced your low and midrange torque by about 30% compared to working aux ports. The engine will idle a little more poorly (due to the aux ports closing very late). Mileage will be worse, and due to lack of air velocity at low RPMs, engine filling is far less efficient thus all these reductions.

That isn't a vacuum line, that is a fresh air line to the injector diffusers.

Did you jump the initial set coupler?

My guess is that most of your problems stem from the old apex seals. After a thousand or so miles, they should clear up at which point you will need to readjust your idle, TPS, and all of the related stuff.

Get a set of 460CC injectors.

Osirus9

iTrader: (10)

+1 to what Aaron said. especially about the used apex seals and low compression.

You will want your aux ports back, all they do is make you gain power, so I don't know why you wanted to get rid of them.

Also, even with stock injectors, N/As run rich. Get an SAFC and a wideband and you'll be able to remove quite a bit of fuel and pick up some more power and gas mileage.