bkm_rx7

This is my last ditch effort, if i dont get much response or help that will lead to the fixing of my problems, im pretty sure im just gonna give up and sell the car and get out of rotary engines.

Ive built a 1/2 bridgeported 12a (click sig for cardomain and go to page 3 for pics, tell me if something there looks wrong) and everything is hooked up correctly. I have no vacuum leaks from what i can tell (most everything is capped off anyhow, the engine is down to the simple things), ive got good spark and fuel, compression seems just fine (way better than the engine i pulled from it and that engine actually ran).

I had the engine running twice so far: once when my dad pull started me and it ran like **** and would die if i let it below 3500rpms and secondly last night when i dumped about 1/4qt of oil in the carburetor when it did the same thing. Both times i feathered the gas and kept it at a constant 3000-4000rpms for about 20 minutes when i tried to let it idle. Both times it died. Both times it wouldnt even give a puff like it was trying to start when i tried to start it afterwards.

Im running a Holley 600cfm carburetor with 56s in the primaries...i know they are small...but ive been told they shouldnt cause this acting up to occur...ive got a holley jet set on the way...so i dont wanna hear about you guys telling me to just buy new jets...

I JUST WANNA KNOW WHY EVERYONE ELSES **** SEEMS TO WORK OUT JUST GREAT AND I ALWAYS HAVE SO MANY PROBLEMS AND NOTHING WORKS RIGHT OR AT ALL!!!!

[/bitching and maybe my love of rotary engines]

RX7WEEE

iTrader: (16)

What were you trying to let it idle at? I know my 1/2 BP would only run at 1200rpms, anything lower than that it'd eat **** and die.

I take it it wont start up with its starter?

Any more info you got will be a help. like how it smells ect...

FB II

i cant remember if you double or even triple checked this in the last thread you had about this, but i know my STOCK port engine did the same thing when i put the turbo and side draft on there. most of it was due to timing. now it still wont idle for **** under 2000 rpms, but i know for a fact now it's fuel. waaayyyy too much. but, it does crank right up now. it's easy to get ONE tooth off onthe dizzy, remember, i know how you feel. been in it for years now. if there's one thing i've learned, it's check, double check, triple check, and then check it again! sometimes, if you take a few days without touching the car, and come back to it.. you might think of something. force yourself to dream about the problem at night helped me some. stick with it. i'm glad i did.

FB II

also, mine wouldnt even make a puff or anything for a while... sounded like the starter was just whirring on not even hitting a flywheel tooth. well, come to find out it wasn't getting enough fuel. you may think those small jets "should" be enough, but i'm willing to bet they aren't. wait till you get the jet kit, it will make a difference.

Eatdust

Sounds like timing to me too. If the only unknow factor is the new engine - (ie carbie, fuel pump ignition coils etc.. worked previously) - Then it must be something with the motor it's self. I would start simple it put a timing light on it and see what's happening. The car should idle and run without the larger jet kit, as long as you keep the rev's and load down!! I'm not so sure about tow starting a new motor...

sr

Hades12

Check your plugs, maybe they Fouled.

speedracer_not

if it starts when towed, and starts when you poured oil down the carburator, then it points to bad compression, Towing will spin the rotor at higher RPM, forcing the seals at the rotor end against the housing (centrifical force).

I had similiar issues. In the end, it ran fine once I put in new plugs (errr, plugs that were known to be good before I removed them after 10 years), and I got the timing correct.

BUMBLEBEE7

iTrader: (1)

first problem jets are too small, you'll need be at least in the70s for jets and get rid of the power valve and buy the power valve block. If you make these changes it should work and also check your ignition system.

d0 Luck

since it's still your new rebuild, you still need to prime it by pouring oil down the carb. this will help 'lock' and build compression to make your car start. all else not equal, check igniters, dizzy and each of the coil contact points, and perhaps fuel pump if they're in working order.

Siraniko

iTrader: (13)

It runs but wont idle. Assuming that everything else are in order, I suspect a clogged idle circuit. If I were you, I will ditch that carb or use a different carb. In fact, since this is a 12-A, try using ur nikki.

mechgod

Check your compression with a gauge, use the trailing plug holes leave the lead's in.
Compression should be no less than 100 psi, also check the pulses of compression make sure there is three pulses per rotor. I just built a motor with used parts last week and had this same problem, No start, floods the motor with fuel

Kentetsu

Okay man, take a deep breath and think about this logically. I know how frustrating it can get, but that won't help you any.

Timing seems to be the most obvious choice, and it can easily be verified if you take the time to do it right. In the past couple of weeks there was a thread floating around here where someone went through all of the steps to verify TDC on a rotary. Find that thread and verify that the following items all line up with each other;

1. Flywheel at proper location to confirm TDC (definitely start here).
2. Front pulley lines up with timing mark when flywheel is at TDC.
3. Distributer lines up with L1 when the flywheel and front pulley are at TDC.

Go through those steps, and you will know for a fact that everything is lined up properly to allow you to time it. Once you have spark, spark firing at the right time, and fuel, it should run. If not, then it will be a lot easier to track down the cause having eliminated timing as a possibility.

Just take your time and go through the steps. Use logic rather than emotions and you will figure it out eventually. Like I said, start by taking a deep breath! Hope this helps some...

DriveFast7

iTrader: (1)

Sounds like the idle is not set correctly. What color are the spark plugs? If fouled clean with brake cleaner and a toothbrush.

Remove the leading spark plug and turn the motor over by hand with 19mm socket wrench. Listen for good solid puffs as engine creates compression. If it wheezes like a chain smoker it's bad compression.

bkm_rx7

I wasnt exactly tryin to let it idle, i was just seeing if it would go below 2500rpms and still run, and it wouldnt. I had to floor it to keep it running. And then it would die if flooring it didnt work. And no, it wont start with the starter anymore.

I think i might not be getting enough fuel, which is unlike your problem you had. I also spent about two hours last night finding TDC by seeing when the apex seal crosses the leading plug hole and marking that spot on the pulley and then finding where that apex seal crosses the trailing plug hole and marking that spot, then lining up the pulley between those marks. Then i pulled out the dizzy and lined up the middle mark on the gear with the mark on the dizzy itself. Now it sounds worse than it did before and still wont start.

My engine sounds like what you are describing, just the flywheel turning. When i put some oil in it, it will make a random puff here and there, but not near starting. Until my jet kit gets here, i think im gonna rig up a DLIDFIS to help on the starts.

I find it very hard to beleive that my motor has bad compression, because on the engine i pulled from it, i could easily spin the flywheel with one hand, whereas with my new engine, it took both hands and some pressure to spin the flywheel. Saying that, my old engine actually ran...Also, i do really need to put a timing light to it, but i dont know how to use one and will have to ask my dad for help with that...but my timing shouldnt be far off cuz i did find my TDC and all like i mentioned.

Yeah, ive pulled the plugs and cleaned them with a wire brush probly 10 times now. Sometimes they are filthy (after i try the oil trick), and other times they are just fine. So this isnt the problem.

Like i mentioned above, i highly doubt i have bad compression due to the flywheel comparison and it DOES have 3 healthy puffs. Im gonna rig up that DLIDFIS and get my timing down to a t and hope for the best.

I hope that you are right about my jets. Im gonna wait til the kit i ordered gets here before i go much farther because many people have said my jets are way too small. Also, im not sure what or where the power valve is. Could you direct me to somewhere that shows this?

Ive tried the oil trick and it fired up once. Then after it ran for about 20 minutes it died when i tried to let the rpms down a bit. Tried to fire it up afterwards and got nothin. Tried the oil trick since and got nothin.

Um, it doesnt really run. I got it started twice, but i wouldnt say it was running. Its not so much that it wont idle, its that it actually wont go below 2500rpms without dying. I suspect its either the jets are WAY too small or something else im not sure about. I really dont think that goin back to a smaller carb will help. Plus, i dont have any other carb i can go back to...my nikki is toast.

I wish i had a gauge i could use, maybe i could borrow one from a local shop or something. But like i said twice before now, i doubt my compression is the problem. I have 3 healthy puffs. Also, i didnt use all old parts, just the old corner seals and apex seals and side seals. Everything else was new. Also, i dont think my motor is flooding, because when i pull the plugs and turn it over, not much fuel spits out.

I did do my TDC and timing and dizzy when it was dark last night, so im gonna go back this afternoon and try to do it exact. Im hoping that will at least make a difference for the good. Thanks for your support, i am really frustrated with all my money goin into this project and now my engine ***** on me like this!

Ive cleaned them with compressed air and a wire brush when i pulled them. Im also getting 3 healthy puffs.

Kentetsu

Looking for the apex seal to cross the spark plug hole is not an effective way to determine TDC (I believe). Keep in mind that there are three apex seals on each rotor, so you might not be lining it up correctly. Start by aligning the flywheel as stated in my last post, that way you will know for sure that you are starting at the correct point. Good luck!

MIKE-P-28

iTrader: (1)

Same thing happened to me when I tried to port a motor. I betcha money you got the ports wrong. You probally have too much port timing overlap or something. I eventually tore the motor apart and had some nice iron doorstops.

bkm_rx7

I dont have timing marks on my pulley. And even if i did, i know i didnt line up the pulley with TDC when i rebuilt it anyways, so i wouldnt trust that mark. That is why i did the timing like i did. Is there a better way?

Check page 3 on my cardomain page (click my sig for cardomain page) and tell me what you think. I have my ports on there. I had them checked out by other members of the forum and they tell me it should run great actually. I didnt go too wild on my ports, so i doubt i could have screwed them up.

Kentetsu

No, no, no! Start with the flywheel (at the back of the engine)! This will place your motor at TDC. Once that is done, put the front pulley on and you will know that it is in the correct position. Then check the dizzy...

Kentetsu

Here's a good link for you to check out. Wackyracer did an excellent job of clearing up the whole TDC matter...

https://www.rx7club.com//showthread.php?t=423913

bkm_rx7

so i have to drop my tranny???

13btnos

iTrader: (1)

http://members.optusnet.com.au/~onec...-%20part%20one easiest way to find TDC. Also do you remember which way the you put the timing gear on? Most don't pay attention to this piece and think it can go any which way but actually it has a bevel on one side and flat on the other side. The beveled side goes towards your engine and will affect your timing if put on incorrectly. If no vaccum leaks and have fuel & spark and good compression then it's a timing issue. Good thing to do to check for leaks is get the motor running and grab a can of carb spray and spray it anywhere you think it may have a leak. The idle will change/fluctuate if you spray where there is a leak. Good luck. Oh a comment on you ports nothing wrong with your ports, timing wise, but hopefully you cleaned them up more than you did in those photos. And also hope you beveled the top/closing of the exhaust port if not your apex seals are going to smack it.

Kentetsu

No. There is a cover that you remove that will allow you to see the flywheel...

bkm_rx7

Yeap, the pics of the ports were right after i finished. I definately cleaned them up a bunch. Also, since someone mentioned the beveling of the exhaust ports was VERY necessary, i went back and beveled those .

krew

Have you set the idle adjustment screws, one each side on primaries?

bkm_rx7

I sure have, 1.5 turns off the seat for each.

Another thing, i just went out and started up my car after my dad messed with the timing all day, only i had to use oil...again. I ran it for about 20 mins, and even moved it a bit. Then i, once again, tried to see if itd go below 2500rpms (cuz it did sound a bit better) and it died...again...weird.

Then i tried to start it up again and got nothing. WHY IS IT THAT I HAVE TO USE OIL TO START IT? could one of my corner seals or something be stuck? also, should i just sit and let it run for like an hour (id have to sit in the car and keep it revved for that long...which would suck)?

Im seriously starting to be bothered by all of this. cuz if i find out my engine is bad...im not pulling open another or puttin another back in...im just prolly gonna get rid of it!