problems with the coil packs
 

Hey guys, so I bought an 88 RX7 GXL non turbo about last November. I just got done rebuilding the rotary about two months ago.
I recently dropped the engine in and turned it over, and no start up.. it cranks just fine. I eventually found out that I have no spark... I absolutely hate electrical work and don't know much about it. I d know that there is something going on with the ignition, I have a strong feeling that it is the coil packs but I just want to make sure and not blow my money on the wrong things and could use as much help as I can get!

Hey bud, if you go to rotaryheads.com, they have the factory service manuals scanned into pdfs. you can go through and find the section where it shows how to test the coils. its pretty nice since you can keep printing them if they get dirty or torn up. I don't know how to actually test them, I'm still new. Good luck

There are two wires in a White plug at the leading coil. Disconnect this plug and make sure the Black/Yellow wire has voltage w/key to on. If not then make sure the EGI INJ fuse is good. If the fuse is good but there is no voltage on the B/Y wire w/key to on then make sure there is constant voltage at the Black/Green wire at the Main Relay. This wire is found in the four wire plug connected to this relay. If that checks out then make sure the relay clicks w/key to on. If it doesn't then check the 15 amp Engine fuse in the interior fuse box. If the relay worked properly you would find voltage w/key to on at the Black/White wire in a three wire check connector plug located right near the leading coil (check connector plugs are not connected to anything and are there for diagnostic purposes). If all this checks out then proceed to check the things listed below.

Also, check the Brown/White wire at the TPS has 5 volts w/key to on. If it does not then the car won't start.

And the CAS needs to be set properly or that can cause a no start condition.

The coils must also be bolted to the fender properly for grounding purposes. No ground means no working coils.

Ok I'll check it out. Also what is this plug for?

Attachment 500705

It's a diagnostic plug for connecting to a tach device. It's not your problem.

Satch I had done what you said bit still nothing. I looked up ohms specs for the coil packs, and the book says .002 to 1 ohms. My multi meter is reading 1.8 so they are bad after all.

Sometimes it's not so cut and dry. One other thing you can do is pull the plug off of the leading coil and w/key to on measure the voltage on the Green/Yellow wire as you rotate the main pulley, which can be accomplished by rotating the alternator pulley. As the main pulley is rotated the voltage should change from 5 volts or so to 0 volts briefly and then back to 5 volts over and over. Most of the time the voltage stays at 5 volts and you'll need to rotate the main pulley a fair amount to see the change in volts.

When you say main pulley do yo mean the eccentric shaft pulley or the alt. Puley

You rotate the main pulley (eccentric shaft) by rotating the alternator pulley.

Hmm, that is strange because I'm not even getting 5 volts on that wire. And when I do spin it, voltage doesn't change. So if that's not right I'm glad sad something.

Did you check the wire at the TPS w/key to on as mentioned earlier to see if you got 5 volts?

Actually, the voltage at the G/Y wire should read 0 volts and then switches to 5 volts only briefly though and then back to 0 volts in a repititious manner.

Sorry it took me so long to get back. Could this no start position with the TPS also mess with fuel injectors too? Because mine are not firing either and they have voltage going to them.

Try and unplug the AFM and see if you get better results. The car will run but it will run rich and should not really be driven as this is just to test to see if the car starts or not.

Please tell me what the AFM is. I'm stupid when it comes to this.

Also I had read on another forum that if you had 12 volts going to your fuel pump its bad. Is this true? And could this also stop your fuel injectors from firing?

Air Flow Meter. Located underneath the air box.

You probably don't have 12 volts w/the car running, do you? If it's too low the pump won't run well.

Hah.. ok so I figured out what the AMF was... that's been unplugged the whole time.

I can't tell. I can't run the car since I have no spark or working fuel injectors.

I had check tps and it showed 5 volts. Now that one test I had done by turning the main pulley and reading the volts off of the leading coil wire, I never read five volts, but I'm not sure I was even doing it right either.

If the CAS is not set right you won't get either spark or fuel injection.

I believe Satch is correct about the CAS. When assembling my 20B, it took a few tries to get the CAS in correctly. If you search " CAS Stabbling", it will give you the correct procedure.

In addition to this, I believe it would be wise to doublecheck for continuity in the wiring between the ECU and coils. In the Wiring Diagram on page 50-28, you should see that 3 wires are a straight line between ECU and Trailing coil, one wire between ECU and Leading Coil. All are located in the ECU connector with 24 terminals (Connector F-31). From here, look for the following wire colors:

Trailing Coil signal wires: Blue/Yellow (AKA Blue with a Yellow stripe), Brown/Yellow, Blue/Red
Leading Coil signal wire: Green/Yellow

Using a multimeter, preferably the digital variety ($5 at Harbor Freight, a smart investment), set it to the 200 Ohm range. Now place one lead on the Blue/Yellow wire at the ECU connector and the other lead on the same color wire at the Trailing coil 4-pin connector (Connector F-35). It should read around 0.07 ohms. This means it is a good, solid connection. If it shows "1 - - -", there is a break in the wire (Infinite resistance, AKA no continuity). If it shows over 0.10 ohms, the connection is poor and will impede the signals from the ECU from getting through.
Repeat this test for the other 2 trailing coil wires and one leading coil wire.

The Black/Yellow wires on both Leading & Trailing coils should only read 12v when the key is ON.

If the wiring checks out fine, power is delivered to the coils when the key is on and the CAS is installed correctly, the next step would be to jumper the fuel pump test connector (Connector EM-30, near the MAP Sensor on the Passenger side strut tower) and see if it will start up.

I got spark finally and fuel delivery! But now I run into the problem of staring it up and revs up to four grand then falls on its face and dies, I'll try again then it acts like it's flooded any ideas?

Plug in the AFM..if it is NOT plugged in to the Harness you get Start and die.