Hey guys, i just bought a 1980 toyota corolla with a 83 rx7 12a swap. The engine is bridgeported, has a racing beat intake and header, and a holley 650cfm 4barrel carburetor. The car is pretty slow and i know it should be way faster. It idles kind of high and if i adjust the idle screw down it will die, it idles like bum bum bum bum (best way to put it i guess). I went to orileys auto and bought some new 6 dollar ngk plugs for it, I flushed the radiator because it had a pumpkin color, I need to change the oil next... kind of seems like the throttle sticks when you punch it full throttle to. Car smells like it is running pig rich and it feels like it kind of busts up a little at higher rpms. Is there stuff i need to adjust or what is up with it. Can anyone give me some kind of advice. Also you have to pump the brakes twice for them to get firm. Any kind of help would be appreciated..
Thanks,
Josh (the new guy to the rotary club )
Edit: Also.. i dont know if the temp gauge is accurate for the 12a because it gets in the red, but i have been told it is not correct as rotary motors run alot hotter. It has an electric fan. It was about a quart low so i put some 20w-50 castrol gtx today since i read that is what most people uses. The car temp only raises up at idle.

 

the idle is supposed to be that way. a bridgeport rotary in a daily driver? you are nuts, lol. what you have there is meant for racing, not just a leisurly cruise, although that is possible. as for the brakes, i'd bleed them all around in this order: RR, LR, RF, LF. you should throw up a pic or five. since the temp raises, you should definatly keep an eye on that coolant and check the condition of your oil cooler.

 

i'd bet that the temp sensor in the engine has the wrong resistance for the guage in the car. that's the problem i ran into when putting an '83 rx7 engine in my '75 808. it would peg the guage and i it wasn't running THAT hot. changing the sensor in the engine solved the problem.

 

A bp should idle 1200-1500 rpm, depending on porting, full or 1/2 bridge. Get an accurate gauge in there asap. Rotarys do not tolerate overheating. Coolant wise, they run the same temps as piston engines, but die a much quicker death when overheated.

Exhaust temps run much hotter. If the previous owner is trying to tell you that the coolant runs hotter, he is trying to unload a problem. If it is getting hot, idling , with an electric fan, the fan and perhaps the entire cooling system is too small.

 

How high into the rpms are you pushing the engine? With a bridgeport, you won't really get into the power until she's really spinning good... If you're trying to drive it like a piston engine (not sure if you are or not), shifting around 3k or so, then I'm not surprised that it feels slow.

 

i think my problem is i neeed a fuel pump.. they said it had a stocker because the good one got stolen so im going to order a holley blue. What is wrong with daily driving it but i think that the temp gauge is off due to it was daily driven when the one dude use to have it and raced it. He said it cut a 12.3 on slicks so

 

You're definately going to need to get over 5k rpm to get the power going.

Also, if it is running pig rich, tune the carb.

 

how do i go about doing that. and do you think a fuel pump will help out if it has the stocker, i have been told that is exactly my problemo

 

If you are running the stock 12A pump on a bridgeport, you are definately not getting enough fuel.

 

If you're going to swap out the fuel pump, check out this thread... https://www.rx7club.com//showthread.php?t=529605

 

so would the carter fuel pump be enough for me? if so that would be great because i really dont feel like paying 100+ for a holley blue.. but also, would i need a safety cut off switch?

 

12a4bbl,
I have a s2 RX7 with a 13b Carby that has an extended bridgport. By looking at your first post i can give you these answers. The idle is higher due to the extended bridgeport. Your lack of power can only be 3 things. 1 that there isnt enough air getting into the carbys or 2 you arent getting enough fuel or 3 you arent getting a quality spark. So change you air filter for the air problem, either check the fuel pump and system, or check that your spark plugs are producing spark. With the spark issue is could also be your coil that could be screwed therefore you would lose a lot of power. I dont know much about holley arbie however with my extended bridgeport and a 52mm webber carby i redline at about 10,000-11,000 rpm, change gears around about 7000 to get maximum launch. In relation to your brakes, it seems like you have air in your brakline so you will have to bleed them to get rid of the air.
Also in rotaries you go through oil because they run on a similar basis as your 2 stroke lawnmower.
I would get the temp guage checked out because the extended bridgeport makes the engine run a lot hotter.

Ryan

 

I'll add one more power restriction possibility, how big is the exhaust?

If the engine is running pig rich, with a Holley, it does not have a stock 12A pump. The Holley needs 5-7 psi, the stock one barely puts out enough fuel for the stock carb at around 2-1/2 to 3-1/2psi.

I have a 1/2 bp and I cannot cruise below 3k rpm, I start to feel power at 4k and it kicks in at 5k up.

 

i just smell gas i dunno though, i might need to get some new coils but supposedly the car ran 12.3 on slicks and the only thing that was supposedly different was a holley 750cfm double pumper and a holley blue fuel pump. I really think it is the fuel pump though to be honest because i was told it was a stocker replacement since the other one got stolen (he didnt want to put anymore in the car and sold it). If i get on it it feels like its not reving high at all. I dont have a tach yet but i will have one soon. But from what it seems like its not getting enough fuel up high and too much at idle/down real low.

 

to be honest what i dont know nothing about rotaries really, like what is bridgeported?? and do i need to stay higher revs riding because it feels like its bogging if i take it easy.

 

Porting is like adding a cam to a piston motor, it moves att the power up in the RPM range. on a bridge I think optimum power is like 5k and above, dont drive like grandma is other words.

 

will the carter fuel pump be enough for what i have done? if i get it do i need to get a fpr?

 

For a bp, I don't know if the 1/4" inlet/outlet will feed enough fuel. Check out the Mallory Comp fuel pumps, that have a larger inlet and outlet size. If the Comp 70 has the larger openings, go with that. I'm running the Comp 140 on mne and it is over kill. I had to replace both supply and return fuel lines with 3/8" line just to handle the pump, along with the 4309 return style fpr. The Comp 110 needs a 5/16" return, which is bigger than the stock supply.

You will need an fpr.

 

Id also like to add that if you are blowing a bit of smoke and it isnt because it needs a tune, it might be the fact that your apex seals are worn. In that case you might need to pull the engine apart and replace them.

 

Smoke, on a worn engine, is usually oil control o-rings or a coolant seal. Worn apex seals usually just make the engine weak.

If the smoke is dark, or black, it's fuel.

 

i will have a holley blue fuel pump w/ regulator tomorrow.. what should if rev to?

 

Depends on which internals and mods were done for the rebuild. Ask the guy you bought it from as to what all was done to it.

 

Actually worn apex seals do make the car blow blue smoke due to unburnt fuel.