Hi All. I generally do fairly minor work on my '93 RX7, but have stepped a bit out of my comfort zone to diagnose a fuel leak. I've removed the UIM and ACV and see that the leak is from the top of the forward secondary injector. At this point, the rats nest is still intact (and looks a little scary). I'm wondering what to do next. I've had one recommendation to pull all 4 injectors and send them out for testing/cleaning. I'm not sure how long that takes, how much it costs, and if it's even worth doing that vs buying new injectors - which are unfortunately expensive. The car is mostly stock and still in pretty great condition accounting for age. I'm not looking to boost performance; I'm quite happy with the car as mostly stock. The engine was rebuilt about 12 years ago, along with new vacuum hoses - so that's not an issue. The vacuum hose running to the ACV is kinked, but otherwise they look fine.

At this point, what's my best option for fixing the car, without tearing apart too much more? What would I be crazy NOT to replace? Do I buy 4 injectors? Do I pull them and send them for testing? What's my parts list? (I went looking at injectors, and found a ton of options with different specs.)

 

There a million possible routes you can take...

To begin, you CAN pull the rats nest as a unit. Check out the album below to get a visual reference of how far you need to go to remove the rails.

https://www.flickr.com/gp/fulldetail...ive/dY9ASdMhaH

Going the path of sending all 4 out to be cleaned is the typical path. There is always the possibility that one or more won't test well and will require replacement. Buying new oem is an option but yes, incredibly expensive. Buying good used is an option as well but how long they will last is up to the universe. Even if all 4 injectors tested and cleaned without flaw, there are cases where they just don't work on install or they die shortly after. Rare, but it happens.

There are some minor seals that should be replaced with the rail removal. Most importantly the 2 "grommets" that go on the primary rail where it seals to the center iron.

Any injector upgrade will require a new ecu. Power fc or better. So upgrading is an option but it comes with a lot of piggy back mods to do so properly.

In this situation, i would advise pulling all 4 injectors and deleting the pulsation damper. Send all 4 out if you don't have a local option and just be prepared for one or more to be bad. Buying good used replacements should be incredibly easy and you would send those out as well.

Its a daunting job to remove the rails in factory configuration but if you take your time, mark everything and take pictures, youll be fine. That photo album may be of some help to you

Also, injector cleaning varies. It depend on who you choose but expect ~$20/injector+shipping, 1 week turnaround and then return shipping. So plan for ~3 weeks downtime.

 

If your car isn’t terribly high mileage I’d go the cleaning route. A good shop will clean and flow-test and they’ll come back with new O rings and pintel caps.

While your in there you might inspect the injector connectors closely. They can sometimes be pretty crispy from heat ( like mine were). New connectors with pig-tails are available and aren’t that pricey.

 

Thanks for the responses. I guess there's no point in testing the one that's leaking from the top! I'll pick up a used secondary injector off ebay and send them in for cleaning/inspection.

@Sgtblue do you have a reference for the injector connectors? Any recommendations on a shop to do the injector cleaning?

 

https://rotaryperformance.com/collec...-set-89-95-rx7

There are others, but on recommendation from a friend and good feedback on the forum at the time, I used these guys (Injector Rehab) https://kgparts.com/index.php?page=fuelinjectclean .

It was maybe 15 years ago. IIRC I had them back it just over a week. Those injectors are still in the car with no issues about 135k total, probably close to 50k miles since….so no complaints.

 

This is a guy I've known personally for about 15 years and is local to me. I will be having him clean mine this winter when I tear into mine. It's the complete opposite corner of the country than you but shipping isn't bad. Prior to this, I've used RC injection with good results to clean customer injectors when I was living in Colorado.

Fuel Injector Servicing (theboostlab.com)

 

Boost lab is a good option as well. They are here in Tampa. We use them regularly so they know exactly what they need to do with FD injectors specifically.... not that they're unique lol