neopj3

So a few months ago I was doing the vaccum job, pretty blue silicone all around, viton check valves, and new injector o-rings, seals and a good injector cleaning at the local diesel shop. well they broke off the pentle caps on my primarys before checking to see if they had replacements and then said "you're SOL buddy" so I needed new injectors fast. I bought a set of primarys from a local performance shop that does rx-7 work. they were used and in a cradle so I took out the injectors and cleaned them myself with some gas and a q-tip. installed them and was happy my car was running great again. well lately my cars been really hard to start and floods like new orleans!!!!! plugs are black and once started smokes and smells like unburnt fuel. adjusted the TPS and checked the MAP and all vac lines. fuel pumps good and the ignition system is good. I looked at the cradle (one from shop) yesterday and noticed that where the stock fuel dampner goes, it's tapped out for what looks like a stand alone set-up. talked to Ray and a few other 7 tunning shops and they all said that running 850cc injectors on a stock computer would explain the symptoms. so I sent off my old stock 550cc's to RC for a tune up. Does this sound about right????? am I wrong to assume that the primarys I got used are 850cc????

dgeesaman

iTrader: (7)

If they are red and shorter, they are 850s. If they are grey/purple and longer, they are 550s. This is assuming they weren't modified or drilled out.

Dave

Fritz Flynn

iTrader: (263)

If it was running good to begin w/ this doesn't make any sense.

I'm betting the injector rings that seal the pintle cape are messed up along with the lower o rings on the injectors letting fuel leak into the combustion chamber.

Just get some new injector seals and reseat them and I think that will fix your problem.

neopj3

the shop i bought these from has a lot of used 7 parts for there race cars. I think they might have gotten these mixed up. the 550 and 850. rx7.com sells 850cc's that look and are about the same size. I figure due to the extremely poor milage, wet plugs, flooding, hard start, and strong unburnt gas smell in the exhaust it's the injectors. I've done every test in the maual and ruled out just about all but the injectors.

Monsterbox

iTrader: (6)

is ur idle rought from funning rich cuz mine sounds the same....poor milage...BLACK plugs after 50 miles

Fritz Flynn

iTrader: (263)

lol

you guys both have the same damn problem

Fritz Flynn

iTrader: (263)

It's pretty tuff to mix up the injectors because the secondaries don't fit in the primary rail.

neopj3

exactly the same. I'm sure the primarys are 850cc. I'm having mine rebuild at RC. change your fuel filter and check your ignition system, tps, and the MAP sensor. my car shot out a 2 foot flame! i'm not joking because I was less then 2 feet from the muffler when it happened. I'm replaceing all my seals and o-rings just to be safe. also if/when you pull your injectors check the impedence, and pull the fuel rail and while the injectors are still in there cradles blow on the line (don;t inhail) and check if any air escapes. that's just my experence.

neopj3

rx-7.com sells 850cc's that are 550cc that are bored out. they look identacal

Fritz Flynn

iTrader: (263)

Please explain how it ran correctly for a while.

That's the only thing that puzzles me.

Anyway good luck with it

Chadwick

iTrader: (12)

They sell Denso stock size injectors, 850cc and 550cc. To use the 850cc as primaries you have to have the stock primary fuel rail machined to accept the larger injector. By RP's price per injector for the 850’s I can guarantee they are not "Bored out" 550's.

Now I'm not saying that yours are not bored out 550's. Only way to tell is to send them off for flow testing.

Hope this helps,
Dan

dom240sx

iTrader: (1)

Just to make sure if you're talking the same thing I think you're talking :p
look at this ''reliability Mods'' and tell me if it look like it :
http://www.banzai-racing.com/pd_elimination_how-to.htm

Holy thread revival to me :p Sorry, I did a research and I did'nt look at the date :S