subieFC fan

i have an 86 rx-7 i just picked up. it has old gas in it so im trying to run it all out. but i noticed that in nuatral it revs up to red line no problem. but in gear it looses near all power at 4k it picks up. but extremly slowly. i heard that after 4k there are secondary fuel inj. that kick in so i was guessing thats it. but i figured i would ask the guys that know first. plugs and wire look new from outside. but tomorrow im going to take them out to actualy check.

RXSpeed16

iTrader: (41)

You are correct, there is a 2nd pair of injectors that only get used above 3800 rpm, on the stock ecu. I believe they are activated using a load/engine speed table so that would explain why the engine rev's strong in neutral (no load) but bogs under acceleration (heavy load). If you give it partial throttle, ~1/4 pedal or so, will it accelerate normally? Secondary injectors get much less use than primaries, so they are more prone to buildup/clogging especially if the car has been sitting long enough for it to have 'old gas'. I'd suggest at least putting some injector cleaner in the tank to help em out. The injectors could need professional cleaning or you may have an problem with the ECU firing the secondaries due to wiring or grounding issues.
Sorry I don't have a concrete answer for you, but hopefully it'll point you in the right direction.

subieFC fan

its all good. anything is better than nothing. i put seafoam in and filled it back to top with fresh gas. ran it for awhile at idle/ bursts. running LEAN very lean. like burning the eyes bad. but after a few hours i took it on the road around the block a few times and its picking up past 3800 now. but in bursts. like it would hesitate bad then pick up, then hesitate. etc. but i can feel it all coming back, so i figued that the injectors were clogged and the seafoam is helping. so im going to let the seafoam/gas sit in the lines over night and hope it eats more away. i cant remember the name for the life of me. but the assembly that has the lights, wipes, turn sig. etc. broke on me bad. givin it was already broke when i bought the car but now its worse so i need a new one. i got lucky that the guy i bought it from gave me 2 bran new cats that are sitting in the back. is it true that the FC with the back seats is rare? i dont care cause they are only big enough to fit a toddler if that

RXSpeed16

iTrader: (41)

Forgot to mention one of the biggest culprits with driveability issues: Throttle Position Sensor (TPS) There's a good writeup in the 'How-to' section of FC3Spro.com along with a lot of good troubleshooting info.
Usually fuel detergents are only good for minor cleaning and maintenance. If the injectors have enough buildup to cause signficant fuel supply issues, I would think they are in need of a professional cleaning. Since you have an NA, this is probably less of an issue, but something to think about if you are still running lean after the seafoam treatment.

Spark plug wires hooked up correctly?
trailing1~>O O<~trailing2 with leading being the coil at the front of the car
leading1~>O O<~leading2 and trailing being the coil closer to the firewall

2 Q's: Is the power loss happen in a consistent pattern or is it random and jerky?
How do you know you are running lean? Oil smoke also stings the eyes, even if the exhaust looks clear.

That's probably enough for now. Hope it works out for ya.

subieFC fan

im going to start on the second question. me and my room mate work on cars everyday. and oil smoke dosent burn like this does. i also perform the vehical emissions testing for arizona so im around exhaust constantly. this is just the first rotory we own. i personaly understand it. but small things here and there i am learning. i did the grounds and after 1/4 tank down she goes past 3800 as long as i ease into it. at any time past if i WOT it gets jerky. we also found another big issue. while at idle i accidentaly disconected the prim. fuel inj. and nothing happened to the rough idle. i just need to get ahold of a tester to see if there is no current going through it. or if its the inj. etherway that became top priority. btw the guy i bought it from put in a bran new TPS, fuel pressure reg. and the MAF also gave me new cats but didnt install the cats.he painted the whole upper intake so i also figure paint on the springs didnt help. please excuse the spelling

Djonyx

iTrader: (5)

I had the same problem when I got my 7. It was the secondary injector, the connectors are shot so I have to use high temp RTV to hold them in place. After that it was heaven, this thing doesn't have a rev limiter I was been able to go up to 8k rpm once. Now I always shift up at 6500 rpm since the power tapers down beyond that point.

Aaron Cake

iTrader: (1)

If you are running "old gas" through the system, you may have just caused some major problems.

See this link, but it's probably too late: http://www.aaroncake.net/rx-7/unstore.htm

subieFC fan

oodly enough after i took the main injectors off i just shitwched them, left-right right-left and she has no hesitation. i doubt that that fixed the issue. they looked like one stock one replaced. but ether way she drives fine now. still minor idle issue when cold but full rev no issues anymore. btw i tried to make sure the old gas wasent alone. i got it down to 1/2 tank and put in new gas with seafoam and runs even better. although it revs fine, i cant get the feeling there is some power loss some where. my buddies 5.0 mustang he removed the smog pump on it and runs fine. i heard that the RX-7 needs the smog pump to run right. sence i do the vehical emissions testing here in Arizona i know for a fact it wont be required as long as my cats are fine. can i run without it? btw on an 86 RX-7 non-turbo is there a way i can buy or make my intake manifold higher performance? that and in the fuse box under the dash there is a fuse port that sticks higher than the rest that had no fuse in it. and it deals with lighting. when i put in the correct fuse it started smoking so i took it out right away. my room mate says that the circuit is being grounded somewhere. i checked the oil. still looks fine. the guy i bought it from said he has royal purple in it. would it be worth it to drain it out and not run synthetic? he also said the u-joint in the axel is cracked. where can i find a stock or near stock replacement for cheap?

subieFC fan

well i checked out your link and it has helped. thankfully the car hasent been sitting for over a year. only 6 months, but he occasionaly went out to start it and let it idle for awhile. i did notice that when im idleing at stand still the "fill collant" light comes on and beeps at me for like 5 seconds then shuts off. while driving no. but the coolant level is fine. and so it the thermostate. im buying new spark plugs here in a few days cause mine are fouled. but not extreme. i was surprised with how the RX-7 spark plugs look compaired to piston motors. took my room mate for a loop. lol. all in all. she is coming to life more and more. just a few more repairs before i do anything performance wise. i already have a 2nd engine for it that just needs new apex seals. sence its a spare motor i have sometime to stip it down. but nothing i cant handle. i cant do gears. i freak out that i will do something wrong cause i never striped a tranny down. but this will be my 3rd rotory motor i have taken apart.

yamahonkawazuki

Ahhhhhhhhh this FNG appreciates teh link VERY much