'94 Rx7 Touring

All stock

Since this Rx7 is all stock it's obvious I just use it for cruising.

Mileage: 43K miles.



Compression:

@250 RPM Cranking speed,

Front:110,106,106

Rear: 104,103,103



I passed emissions for the last 3 times(2003,2005,2007). I only put 10k miles on the car since 2003. For the last year I've driven this '94 Rx7 around only once every 2 weeks and as little as once a month. Now I failed emissions for the first time. My mechanic, who did the 2500 RPM emission test, said that my Rx7 is all "gummed up". He told me to replace the plugs and drive it alot, which I've been doing. But now I'm replacing the plugs and plug wires. One plug wire was disintegrated inside the leading coil so I ordered a new coil. Also the double throttle solenoid, which is the first one with the green plug, had a broken end. The solenoid end that was broken had a hose that lead to the UIM. So I ordered this double throttle solenoid too. All the other solenoid hoses look in good shape. Since I have the solenoid rack out and exposure to the fuel rails should I replace the injectors? What about the O2 sensor? What are some good areas to test with access to the solenoids, fuel rail, idle air control valve, and the removed UIM? Just wondering if there were some "no-brainers" that I'm missing.



Thanks

 

"I'm replacing the plugs and plug wires"

"One plug wire was disintegrated inside the leading coil so I ordered a new coil"



Have you had the emissions checked again since you did these things?

Since you`re going over the car, I would look at the air filter & fuel filter too. Couldn`t hurt to replace them unless you are the original owner & have kept the car maintained over its lifespan. I am doing an engine replacement in my car right now & went ahead & bought a new O2 sensor to put in. Seems like I read somewhere that replacing them every 50K miles or so was a good idea to keep them in top running shape. Mine looked fine physically but after 100K+ & a new engine going in, I wasn`t going to skimp on a top running car. Your fuel injectors don`t have a lot of miles on them really. If you want to get new ones, think I would rather take them out & have them cleaned instead. It will cost you a whole lot less. You`re in there now so, your call.



If you also have everything out & the rats nest is in your hands, You could check each solenoid in it for proper operation & for vacuum/pressure leaks. Also check the PCV valve or replace it with a new one entirely & check those other little white & green vacuum valves too. The manual will tell you how to do it. Easy actually.



Take care.

 

*I'd go ahead and put a new coil harness in while your there.

*I wouldn't buy NEW injectors, but pull those and send them in for cleaning and flow testing.

*+1 on making sure your air filter is clean.

*O2 sensors are pretty inexpensive and relatively easy to change so yes, replace it.





I don't have emissions in my state so I'm curious, do you do testing with the engine at full operating temps?

 

Yea my mechanic does testing after warming up and driving the engine to get the cat heated up.

I don't even have a down pipe LOL.

Although I should put one on because they are recommended for reliability. Also, no state checks emissions for cold start, which is what the precat is for.



Thanks for the responses.

I'm going to send my injectors for cleaning. I see WitchHunter and RC Engineering on the net. Anyone have any experiences with them or recommend a better one?



Also, e-mailed Dave Barninger(www.KDRotary.com) regarding this thread about what to replace and test with the solenoid rack out.

He emailed back the following:



"injector wise ..especially with all the time that has gone by...not a bad idea..but def not nec...

on the solenoid tray we ususally do not have problems with any one solenoid..the biggest failure rate is the solewnoid on top of the air control valve...N3A1-18-741...check resistance...should be 28-38 ohms...usually they read in the 45 plus range and then when they get hot they shoot off the map with resistance...



your bad coil and wires will def kill the emmision test...should fly thru once back together...



hope thsi helps..dave@KDR"





I checked this solenoid and it's 34 ohms. 8^).

 

so now that it has a tune up put it back together and go get the emissions done again. it should be fine.

 

Thanks,

Oh and here's the solenoid Dave Barninger was talking about.

 

well it sounds like your on the right track where did you get that pic from?

 

FWIW I sent mine here and was happy http://kgparts.com/index.php?page=fuelinjectclean but heard good things about RC too.

 

you should also get the fpd replace, sometimes they go bad & start leaking fuel which may cause a fire. for your fuel injection service i recommend rc eng i had a couple inectors clean & tested by them & they do a great job.

 

I went to KGparts. They had a branch just 10 miles away. I sent my injectors through regular mail at 9am. KGParts received them the same day. Delivery cost me $5. RC Eng looks good too but they are across the country.