4thgenlude

I bought an 1988 NA, shell a few months ago and put a used engine in it. I saw the engine running before i bought it, so I know its good.

I been real lazy with it, and just yesterday I got everything all together.
But now it doesnt want to start, the car had been sitting for a few years, but im pretty sure i drained all the gas out, and put two new gallons of premium in.


I have yet to diagnose anything yet, but is there any common things I should check first?

Also, im not 100% positive I put the spark plug wires in correctly, the trailing spark plugs are on top right? And the fisrt rotor is the one closest to the front of the car?



thanks for any help!

Ill update this as I diagnose things!

thanks

-Charlie

diabolical1

iTrader: (3)

welcome to the board!

yes. front = 1, rear = 2. trailing = top, lead = bottom.

check fuel and spark first.

when you get crank it, are you hearing any signs of combustion or is it just moving air?

4thgenlude

no sounds of combustion at all, sounds like just air to me.

But I dont have the exhaust hooked up after the downpipe, and I noticed some whiteish smoke coming out when I was cranking it.

Are the fuel pumps noisy in these cars usually? Because I dont hear anything when I move the key to the on position.

Thanks for the reply!

diabolical1

iTrader: (3)

check the fuel at the rail.

i'm at a bit of a loss when it comes to the fine details of the FCs, so you may want to start with the Gen II section FAQ or just search for fuel pump threads. either way, i'll have to defer your question on if they are audible to someone else that has more experience with them.

did you have to reset the CAS or was the engine installed with it in place from the last time it started?

4thgenlude

well i just put an old spark plug in one of the plug wires, and grounded it, then cranked it over, and there wasnt any noticeable spark. Does this way work for testing the spark??

4thgenlude

well theres definitely gas coming out of the downpipe, and no spark from what I can tell.

I checked for power at the coils, and the little two prong clip for the trailing coil pack is getting +12v at both prongs. And on the leading coil pack, I checked the black with yellow stripe wire, and it was also getting +12v.



Also I checked the resistance of the CAS and it checks out!

Any ideas??

4thgenlude

help!

CasperIV

Well, if the coils are both getting power, how does it look beyond that point? Hows the cap and rotor? Basically what your saying is that there is power up to the coils and not beyond. That would lead me to believe that you have a problem in the wires or cap and rotor.

You will have to forgive me, I haven't worked with FC's as much as other cars, but basically you just need to chase the spark. Start working your way down the system until you figure out where it stops working.

4thgenlude

Im pretty sure, these dont have a cap and rotor. Ill check everything over though, and just follow everything back like you said though!

thanks!

4thgenlude

anyone else?

4thgenlude

bump bump bump!

Tach is not moving at all.

Project84

The tach gets its signal from the rear coil/igniter assembly. If yu have a '86 & up fuel injected engine, it won't have a cap and rotor, it will have a CAS (Crank Angle Sensor). If you had this removed, it needs to be installed with properly for the ignition system to work. Their is an index mark on the engine front cover just above the main crank pulley. The pulley has 2 marks on it, one of which must be lined up with the index mark. The CAS also has 2 index marks, one on the rotating gear, the other on the housing itself. Align these two marks and install the CAS. In my past experiences, I have discovered that the CAS does not always stay aligned when you install it because the teeth on the gear has to mesh with the teeth on the gear down in the engine. The beveled teeth cause the CAS to turn. What I do is remove the black cover off the top of the CAS, align the index marks, then make a mark with a colored marking on the CAS housing and the rotating pointer under the little black cover. This will all appear very obvious when you get the parts in front of you, but what this does is allows me to install the CAS, verify the alignment afterwards. If the marks move away from each other after you install it, simply rotate the housing until your marks line up again. The housing has room to rotate when installed.

Also, you might want check that the wire harness in the car and the ECU in the car are working properly. You might be having electrical problems associated with that.

4thgenlude

Oh my goodness, I cant thank you enough!

ll try this out when I get some free time! Thanks a bunch!

4thgenlude

okay, so I took the CAS out, and spun it with my finger with they key in the ON position.

Nothing happened, I didnt even hear the injectors ticking, then I re-installed it with the marks lined up and tried cranking over again to no avail.

I also checked the engine fuse under the dash, and it was fine.


Any ideas??? Could the ECU be dead?

4thgenlude

One more thing, I heard a light buzzing sound coming from the drivers side of the engine bay when I left the key in the ON position, what could that be?

pfsantos

iTrader: (1)

The buzzing is normal and comes from solenoids and relays.

You said you didn't see a noticeable spark. Re-check easily by pulling off each boot (one at a time), putting a wire in the boot and placing the other end of the wire near a good, clean ground. Re-check all your fuses (near the driver's side shock tower and inside near the dead pedal), especially if you don't know which ones do what. You want to be *certain* whether you have spark or not.

You also mentioned some doubts about the fuel system, but said the exhaust smells rich, so that shouldn't be the problem. Having said that, here's some info. To check fuel pump supply and rail pressurization, turn ign. on, and jumper the two pins at the yellow plug designed for this. The plug is near where the snorkel meets the back of the AFM (air flow meter). You should hear the fuel pump buzz and shortly after fuel hissing past the pressure regulator back to the tank. PM me if I don't bug you soon as today is the first time i'm in this section of the forum and I want to know how you do.

4thgenlude

I know that the fuel is getting to the rail, and its properly pressurized.


I think the Main relay is bad, I took it off and put 12V between various pins on it, except the ones that said coil by them, and I never heard a click or any sign of the relay functioning as it should. Im going to Mazda tomorrow to pick up a new relay, so well see what happens!

And thank you for the reply!!

4thgenlude

well the relay I thought was the main relay, was definitely not the main relay. I tested the real main relay, and it was fine.

Okay heres a cliffnotes:

-Not getting fuel past the injectors, but theres fuel at the rail, and its pressurized.
-Not getting spark
-The coils are getting power
-The main relay is good
-With the key to the ON position, I took the CAS out, and spun it manually, and nothing happened, no spark no injectors ticking either.


Whats left? Wiring harness? ECU?

4thgenlude

no ideas?

4thgenlude

Okay, I just figured out that the ECU is not getting power, on the little clip. Nothing at all.

Also the main relay is getting power, and so are the coil packs? Any ideas?

thanks much!

-Charlie

4thgenlude

Also, pins 3A and 3I on the little clip going to the ECU have continuity!?!

According to the FSM, pin 3A is ground, and pin 3I should be 12v to the main relay. Im very very confused!

4thgenlude

no? nothing?

4thgenlude

you sure? nothing at all?

pfsantos

iTrader: (1)

Do a temp. connection to the Ecu wherever it needs 12V (+). See if she'll start then. Try to swap ECU's if you have one lying around. If the ECU isn't getting power, focus on why and eliminate that first.

4thgenlude

you mean just connect +12V from an external source whereever it needs it?

Seems dangerous to me! Im nearly done with summer school, and after that pretty much all my free time is going towards making this car run!