junito1

I chased my problem down to 2 possibilities.
My front rotor primary injector or the plug to that injector being bad.

How could i go about doing some tests to find out which of the 2 is bad.?

This is how i know one of these 2 HAS to be the problem.

Original problem is that my engine ran on one rotor.
I did a ghetto test but i do have spark to every single plug wire.
SO i have spark!
I then disconnected the spark plug wires to the rear rotor and tried to crank it with no results. Just kept turning, and didnt even sound like it tried to ignite once.

Then i swapped it. The now disconnected front rotor and connected rear rotor. The motor actually cranked. and ran barely idled with one rotor like it had been doing.

farberio

iTrader: (7)

Check for compression, you should have 3 puffs of air per revolution when hand cranking it.

RotaryRocket88

iTrader: (7)

+1

You probably damaged an apex seal.

junito1

OMG. Im telling you guys im not getting fuel to the front rotor and and you guys say its the compression.

No fuel = no combustion guys.

HOW. do i test my injector plugs or injectors.
I must test one atleast to see which of the 2 is good.

hanman

"No fuel = no combustion guys." WRONG.
Just because there is "supposedly" no fuel, doesn't mean you don't have compression. The guys are suggesting that you test the compression first. It's a more likely problem that one bad injector.
To test the injector, you on one side of the connector you should have constant 12V with the key on. The other side will pulse to ground as the car is running.

What happens if you spray some starting fluid in to the intake, will it run on both rotors for a second or two? If not, it sounds like compression.

farberio

iTrader: (7)

If you absolutely know its fuel, then get all of your injectors rebuilt and flow tested and you don't even have to start a thread.

If you want the advice of the forum, which has a wealth of experiance and knowledge and likes to cover all bases, as opposed to running around screaming about a wrong conclusion then be nice and realize that the people on the forum probably have good reason for suggesting what they do.

HAILERS

You've a blown motor, as in broken apex seal.

It's easy to see if a injector is good or bad. Go to the ECU and pull the plug off. Find the wire for the given injector. Put a meter on it to see if it has battery voltage on it with the key to ON. Should.

Then momentarily touch that wire to gnd. You should hear the injector click each time you momentarily touch that wire to gnd with the key ON.

Your motors blown. Call the wrecker to haul it off.

junito1

Come on guys. I said i chased the problem down to the cause.

read this then get back to me. Other experienced members have already predicted its the plug or injector before i even chased the problem down with the little tests they gave me to do on the car that lead to my plug or injector conclusion. Thread \/\/

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/primary-injector-problem-756561/

PS. For the guys that think it is a blown motor. This event prooves it isnt blown.
I was driving down the highway about 70mph, then out of nowhere, the car is suddenly running on one rotor.(i was freaking out). I kept driving because i was on a bridge that i could not stop at. Anyways by the time i made it to the end of the bridge the second rotor had came back at full potential. I even went 2nd gear WOT and the car had full power, this is besides the fact that i took the plugs out already and there are 3 even puffs coming out of the front rotor.

SO when i say i chased the problem down. Believe me. I did.

platinumyama32

buy new injector connectors ($6 each=$24)
get your injectors cleaned and flow tested ($12 each=$48)
install (free=yourself)
total=$72 for all your worries

/thread

ilike2eatricers

could be possibly burnt out injector driver on the ecu. has happened to a few people before.

HAILERS

What part of the above cannot you do? In fifteen minutes or less?

junito1

im goin to try it. But im trying to test the actual injector plug first. And im already lookling into new plugs and injectors.

farberio

iTrader: (7)

If you want to test the plug itself you can test it with a DMM continuity tester. If it beeps going from connection on the ecu to the connection on the injector, then the wire is good.

Elbi

iTrader: (1)

Don't mean to thread jack but I'm having this exact same problem. I'm almost sure its an injector, but it could probably be one of my leading plugs. I've checked for spark only on my trailing coils and plugs(the ghetto way) , I just don't know how to check the leading coil for spark (I don't know why but I feel like I should be scared of it..lol). I already checked for compression with a gauge last night and my results were fantastic(110ish front/115ish rear,also checked for 3 even bounces on each). If you guys could just keep replying to this guy, I would surely benefit from this thread without starting a new one. Sorry again
Rob

gxl90rx7

iTrader: (1)

jus tdo what hailers said, if it is a bad connector, then it wont read 12V. another thing to try is probe the injector connections at the ecu (12V and injector pins at connector 3, key to on), set your meter for audible tone and wiggle the connector at the injector to see if it breaks up

elbi, just pull the plug wires off the leading igniter, you should tell pretty quickly if its getting spark.. dont worry about it shocking you, its happened to me a couple times, its not that bad

junito1

I dont follow the intructions though.

If someone could just explain it to me like a baby.

Like which pin on the ecu is the correct one? Whats a DMM continuity tester?
I all have is a regular test meter.

Im a newb to mechanics but i can shange transmissions

Elbi

iTrader: (1)

lol...will do
That's what I did to see if I had spark for the trailing coils. The only reason I didn't do it to the leading was because in the haynes manual they show you how to check resistance in coils for trailing only. When it comes to the leading coils they tell you that you have to take it to a shop with some special machine so I was a bit hesitant to find out 1st hand if the shock was any greater between trailing and leading coils. Thanks though I'm about to start working on her right now so ill check back with you guys later on tonight.

hanman

Take a look at the factory manual, it has the ecu pins mapped out. Just check and see which pins are for the injectors, then follow Hailers advice.

HAILERS

You continually say you think it's a primary injector problem. So all you have to do is swap the primarys with the secondarys and have at it again. It's doubtful that all four are bad injectors.

If you don't do that, then:

Somewhere in all this you say you have a 88TuboII wiring in the car. So go look at the online FSM, Wiring, and see which are the primary wires at the ECU. If you looked you'd have seen that they are in the small ECU plug. All the injector wires should have 12vdc on them with the plug pulled off and the key to ON. The colors are LIGHT GREEN. LIGHT GREEN/WHITE. LIGHT GREEN RED, LIGHT GREEN/BLACK.

All should have 12vdc on them with the key to ON. IF you momentarily ground any of those wires, the injector for that wire will click. You don't want to gnd the wire for more than one or two seconds at a time.

junito1

No, they arent all bad. But if i swap injectors it would have to be with the other primary because i lost my original 2ndaries after i installed the 720's.

HAILERS

Do you own another engine or have a spare CAS?

junito1

No I do not own extra engine/cas.

Ok guys. today i did another ghetto test. I did not like the results.=(
I removed the primary fuel rails with the injectors. I held the injectors on the rail while a friend cranked the motor. Both injectors sprayed.=( One thing though. My fuel was extremely dirty. Like i mentioned before. The prob started when i added a bit of 2 stroke to the fuel tank because i was going to drift.
I dont even remember when i last replaced my fuel filter.

But, I guess my motor is done.=(

junito1

Great news. WHen i took the injector out of the fuel rail. It was extremely dirty. There was crap in there that was obviously too big to be in my fuel. I drained the fuel line a little. Put everything back together. AND WALA!!! Shes running like she used to. Im going to get a fuel filter.

ALso what kind of fuel cleaner would you guys suggest. SEafoam?

sharingan 19

iTrader: (16)

I've put Seafoam in the tank and in the oil (right before changing) w/ good results. I've heard its not such a good idea to suck it in through the intake though (on a turbo motor)

junito1

Ok bad news. LOL. Since i "Fixed" it yesterday, I let it idle for about 30 mins. It idled beautifuly. I drove it around my neighborhood smoking a blunt then-- when i was about done with my blunt it all happened again. One rotor. SO it lasted about 1 hour running right..

I think the best way to fix all these would be
NEW fuel cell,fuel pump,fuel lines,filters, and injectors.

What do you guys think?