Have a rebuilt motor with 2K miles on it.

Stock ECU and pressures. Stock Twins. Stock factory motor.

Before making it a garage queen, was running good. Noticed before it quit running well, it would intermittently after warming up, run on one rotor. Now all it does is run on one rotor. The rear rotor has no fuel. On start up, pulling the rear plugs, no smell of fuel on the plug. My injectors were sent out to be cleaned before I put the rebuilt in. After 2K miles or so, no joy.

Stuck closed injector maybe?

ECU?

If I can break 5 PSI and the secondary comes in, no joy either. Cough! Cough! Sputter. No joy.

Replaced the coil units too.

 

Swap out your injectors and see if it cures the issue. I have had numerous cleaned & flow tested injectors fail on me. Seems the cleaning solution can solidify inside the injector if they sit a short time prior to install.

 

I have heard the same story from someone else too. I wished I would have known that cleaned injectors can stick later after installation. I would have just gone off and bought new ones and saved myself a headache.

Can the injectors be pulled out with the motor in the car? When I put everything back on the motor, the motor was out and it was very easy to assemble everything that attaches to the block.

 

Yes, they can. But obviously it's a bigger job.

 

if it started the issue prior to the injectors being cleaned i would suspect it being an electrical issue first and then the injectors secondary.

unfortunately you need to pull the UIM and do some testing. check to be sure all 4 injector clips are getting 12V with the key on engine off. next inspect the injector clips thoroughly for pushed in pins, corrosion on the pins of the connector and injectors and lastly the locking clips for the injectors. replace any injector clips that you suspect to not be in good condition.

yes i have also seen numerous cases where injectors are stuck just after getting them back from servicing, some shops are too cheap to use storage solution on the injectors because it adds another step to the process... but usually the injectors either will work or they won't, they usually aren't intermittent.

moving the injectors front to rear and vice versa will tell you if it is the injectors or an electrical issue. same can be done with suspect ignition components.

 

Good to see you, old friend.

I think you know my street story quite well!

 

Never had the problem before the new engine went in.

After getting back the injectors from cleaning, it was around a month I think, before I put them in. They did initially stick. I unfroze them with a 9 volt battery.
After that, I got 2K miles on the car before it didn`t want to run. I would think that if the car made it to the secondary transition, it would take off like a bat. It doesn`t. Strange. 2 stuck injectors? One on the primary side and one on the secondary? Same rotor? What are the chances of that happening?

 

Pull the UIM and test each of the injectors. Stop trying to push the engine to transition until you have your primary injector issue sorted out.

First thing you should do is change your spark plugs to rule out a bad plug.

 

if you make it to the transition point then you have 1 rotor recieving the correct amount of fuel and one rotor running about 65% of what it needs, the car will never perform well that way and it will spit out a seal on the lean rotor or warp the seals if you continue to try.

 

Car hasn`t been driven in quite some time. I occasionally turn the motor over a rev or 2 to keep it from locking up. Outside of that, no road miles at all.

I changed the plugs right off of the bat. My thoughts too, on a fouled plug. Still didn`t do anything.

 

Do the primary injectors cut off and the secondaries come in at transition or do they all flow at transition? From what you are telling me, I am getting that they all flow when the 2nd turbo comes in.

 

All the injectors flow together after 3700 rpm, but only under load. If you have not actually driven the car you have not engaged the secondaries. I do not recommend that you take it out and force the secondaries to open, good chance you break the engine.

Pull the UIM and test the primaries.

 

"All the injectors flow together after 3700 rpm, but only under load."

Thank you for that info! I wondered about that!

Car hasn`t been driven in quite awhile as stated before. Until I can get this issue resolved, the car remains a garage "queen".

Last time I had this problem, pulled plugs to both rotors. Nice loud PHISH! PHISH! PHISH! from both rotor housings.

Only problem is, front rotor with plugs removed leaves fuel vapors in the air and the rear doesn`t.

When the car ran on the interstate and the problem came up, I managed to get it over 4500 RPM`s with the foot on the floor. Waited for the secondary turbo to come in...it did. Still coughed and sputtered. No power. Hmmmmmm. No secondary injector on that housing???

Looks like I need to pull the intake manifold and do some voltage checks.

 

Nat,

Didnt lose my number did you? I have several un-cleaned injectors laying around. Im sure you remember what I told you a couple years ago when you told me you had them cleaned. I personally say either run the originals the way they are or buy new ones. Cleaned and flow tested injectors have give me nothing but headaches over the years.

Either way I have several you can have to get the car back running right.

 

I have used your number enough that it is still stuck in my mind after all of this time!

I remember WELL what you mentioned! I am at the point that things are cooling off weather wise and I NEED to get the ride back up and running. I also NEED to get motivation ( which I am starting to slowly have ) and get off my butt and just dive into this thing. Boy........I really don`t want to have to pull that motor out to do this..............

 

why would you have to pull the motor out? even the primaries can be replaced without removing the whole rat's nest, UIM is a little painful though.

 

....

 

I can`t remember how hard it is to get to the secondaries. I know that everything is really tight on that side of the motor to work with. I am at the point after thinking about all of this and dreading doing it, that I am going to spend the money, buy new injector plugs and injectors, and not have to worry with this again. Money is the issue right now and has been for awhile.

If I can get away with not pulling the motor, I may suffer a little longer during the process and just go that route. Still not sure.

DJ,
you still doing engine rebuilds or has family life taken over?

 

Never had the pleasure of changing injectors in the car Nat. But while it won't be a walk in the park, I'm sure it's doable. Break-out the FSM, get one of those elastic back-support things the delivery guys wear, get that UIM off and get to it.

Not certain, but I'm thinking one of the forum vendors (IR Performance?) used to offer replacement injector pig-tails. They we're much and depending on the condition of yours...

 

5th from the bottom
KGParts.com - KGParts Fuel Systems

 

I don`t feel like this is a pleasure at all! True pleasure is derived from driving your 3rd gen down the road on a warm summer day and listening to some tunes with the top rolled back. Some Boston would be nice. Maybe " More than a feeling"?

I think you know how soiled my FSM is.

As far as the back support rigs go...........maybe a trip to the Doc for some back pain meds would be better! Maybe see if I can get some brain meds too!!

In my internet travels, I seem to recall running across those pigtails. I`ll have to check my bookmarks for the Mazda related stuff. I know I have that info somewhere in all of them.

I know I need to get to it.
Jim, you were always good for moral support! Thanks for being the trooper that you are!

 

Thanks for putting up that link!
I`ll keep that info close by!

 

I'm thinking I may have an issue with cleaned / flow ported injectors

I've taken the UIM off a few times so that part doesnt scare me what does though

is I dont really know how to test them .


maybe this may help the OP as well


These are my thoughts and questions ..

Rotary evolution , you said that with the ignition on , and engine off of course it should be receiving 12v ??

so the injectors work with ground and have constant positive?

Also is there a way to test them? say

jump the fuel pump on the Diagosis box

then go to each injector one by one and give it ground + pos to see if they open up and spray?

 

It is definitely possible to remove injectors with the rats nest in the car. Remove the aluminum retainer at the top of the primary rail and pull the injectors out of the top of the fuel rail. Careful as there should be fuel pressure so watch your eyes and surroundings. I had to remove my primarys a few years ago when I had stock injectors after a cleaning one stuck shut. Had to hit it a few times and all was well for 12k miles until I removed them for larger ones.

.

 

my primaries are working well , I think my problem is the secondaries . which are the top ones so I have it easier then the OP