ok guys this is the deal. i replaced the factory FPR with an aftermarket FPR and the car iddles very crappy. I cheked for compression and i still have 100 psi on each face on each rotor, replaced all the vaccum hoses, cleaned the fuel injectors and replaced all the o rings and seals on them, replaced the intake tube and air filter, all the hoses from the turbo to itercooler and to the throttle body, cleaned the spark plugs because i couldnt find them in any auto parts here, new thermostat, all gaskets on the intake manifold and the water o rings. the car runs fine and builds great boost but it iddles very rough, it doesnt die. the car is iddleing arround 750 rpms. i have the fuel pressure set at 37 PSI as recomended by another member. the A/F ratio gauge is on the lowest setting of lean when in idle for a while then it keeps on going up gradually to the good setting then goes back down and so. it just slowly goes up and down. it also backfires a little no fire out of the muffler but you can hear it poping. took the alternator to get tested and it is fine. I sprayed starting fluid all over the engine and didnt find any leaks. i read all the posts i could find relating to this but couldn't find anything that would help me.

the car in question is a 87 TII, the only mods to it are 3" exhaust from the cat down and pipes, aftermarket intake tube and air filter, FCD, Aftermarket BOV, and the fuel pressure regulator.please help.

thanks in advance.

 

how did you set the fuel pressure? It needs to be set with the vacuum hose disconnected. You may have a vacuum leak or a TPS that needs to be adjusted.

 

i set it by putting a jumper cable in the yellow plug in the passengers side shock tower with the vacccum disconnected and the swith to on. I checked for vaccum leaks and found none. like i said i sprayed starting fluid in all the hoses and gaskets in the car. is there a visible way of knowing if the TPS is out of adjustment?

 

no there is no visible way, you either need to hook up an ohm meter or rig up the two lamp tester. check aaron cakes site or rotary resurrection or rotorwiki for instructions.

 

Polito, ajusta la presion del regulador con el motor prendido y el vaccum desconectado. Asi yo le elimine ese problema al mio. El mio tiene la presion a 45psi (sin vaccum), pero el motor esta alterado.

 

gracias mano despues lo chequeo pero no le voy a poder meter mano hasta el fin de semana. despues escribo y te dejo saber que paso. de que parte de la isla eres? yo soy de Rio Grande pero estoy por aca por el ejercito.

 

(For those who don't speak Spanish)
Polito, adjust the regulator pressure with the motor [idling?] and the vacuum [line] disconnected. That's how I eliminated this problem on my car. Mine has the pressure set at 45psi (without vacuum), but the motor is modified.

Thanks, man, I'll check it out later, but I won't be able to touch it until this weekend. Afterwards I'll write and let you know what happened. What part of the island are you from? I'm from Rio Grande, but I'm here in the (Army?).

-------------------------------------------------------------------

How did I do?

 

Well, I'm in Guayama, that is in the south, like 1 hour and 30 minutes from Rio Grande. I have a cousing that is in the Air Force. He is right now at Okinawa in Japan. He is aviation mechanic. His name is Sgt. Diaz.

 

What is the fuel rail pressure when idling with the vacuum hose connected to the FPR?

 

it fluctuates a little with the idle but its between 32 and 35 PSI. I did find something that i might need your guidance on. I taught there was no vaccum on that spider that goes from the UIM's third nipple on the firewall side to the oil injectors, but for some crazy reason i decided to spray jet start at the one visible from the front and the idle changed so as of now i'm thinking thats where my problem is at. i changed the hoses on it for new ones when i was putting my car together because the old ones were very toasted and broke when i was taking the car appart. But I'm 99.9% sure that there Isn't supposed to be vaccum there. I saw this part on the MAZDATRIX site and they call it a vaccum spider. I aslo went to the mazda part catalog and it's called connector air tube and the part number is N326-14-617 just in case no one understood what i am talking about. should i go ahead and replace it or should i go in another route?

thanks in advance.

 

You did great. thanks for the translation!!!

 

are oil inectors supposed to leak air on the top lid not on the nipple but in the outside of the top lid. when i blow air into the oil injectos the air comes out by the sides of the top part of it. is not the lines like i taught and when i create suction on the hose to it the same thing happens it suctionates from the same spot. is that the way it is or should i buy new ones?

 

I'm pretty sure they shouldn't leak any air.

 

The rotor on its intake stroke draws air thru the oil injector. The vacuum line on top of the oil injector goes to the spider. The spider gets fed from a large nipple on the back of the turbo throttle body. That large nipple is in turn fed air from a passage prior to the throttle plates.

The oil injector should only pass air in one direction. From its top to the bottom. If air flows both directions, it's a bad oil injector. Download the FSM and the LUBRICATION section.

Never connect a oil injector to a source of vacuum. The suction comes from the rotor, not vice versa.

 

btw if you are using a narrow band afm gauge you cant read it at idle for any accuracy...

narrow band only reads when you are accelerating.. thus why the gauge will bump up and down...

as for yoru problem to me it sounds like the fuel pressure was adjusted innacuratly and it is to high or low, or you have a vac leak

 

the air is not leaking from the oil injector nipple its leaking by the sides of the top lid. the checkvalve on it is working. i made this draw of where it is leaking the following pic is an above view of the oil injector

 

Is there a certain level of attainable boost that would make that pressure difference too low so it would stop working as it should?

 

hey man if you could please re phrase what you just said. i have no clue of what you ment!!!

 

He said the suction from the rotor spinning (opening the chamber) draws in the oil from the oil injectors. Technically, this suction is simply caused by there being lower pressure in the chamber during that time than the pressure in the OMP lines. When you raise the intake pressure you naturally increase the pressure in the combustion chambers (before, during, and after combustion occurs), so I was wondering if there's a reachable boost level that could overcome the vacuum caused by the rotor opening the chamber and in turn keep oil from coming in at the rate it needs to.

 

The mechanical omp puts out more pressure than you might think. If you plug three of the four output holes on the omp, and then put a pressure gauge on the remaining hose, you'll see at least forty psi if you rev the engine up. The pressure does Not come from the engine oil pump, it's coming from that little mech oil pump. Been there, done that, in another post somewhere out there in cyber space.