got new battery, new starter hit the key just turns and turns never fires up. checked to see if sparks at spark plugs nothing then at coils nothing. what should i check now?new spark plugs to?

 

Check all the easy stuff - check all the fuses under the hood?


-Ted

 

all the fuses are fine.

 

This is HAILERS territory.
Do a search with HAILERS as user name and ignition as key word, you should find help.

in any case,
a bump does not hurt.

Hugues -

 

Next to your left foot there is the fuse box. See if the ENGINE fuse is bad.

[img]https://www.rx7club.com/forum/attach...postid=1398717 [/img]

 

<HAILERS imitation>

go to your leading coil with the key in the ON position, and find the 2 wires that go to it. ONe will be green, you may or may not see 5vdc on this one, but it isnt as important right now. The other will be black and yellow IIRC, check for 12vdc there (with your dmm grounded). If you dont have 12vdc, trace back to the main relay (d. side firewall by clutch MC) and check to see that it clicks when ignition is turned off and on, and that 12vdc is getting switched on there.

report back with what you find.

</HAILERS imitation>

 

Darn:

Double darn:

 

ok. i checked the fuse inside by the cpu and they were ok sept the 7.5 room fuse it was toast. then hooked up batter and all the lights on the dash and idiot panel came on and stayed on then turned the switch to on and after about 2 seconds a buzzer started going off. then checked at the leading coil green ... 0 checked the other it had 12.22???? so now what should i check?

 

relay has been tested about two months ago. it was fine

 

I believe the next step is to try another ecu, or at least check the connections thereto...

the 12v at the coil means theyre getting power, just not signal (apparently) to fire...

 

Bryant just because it was tested 2 months ago doesnt mean it works now

 

Ugggggh! Not a pretty sight. 12v at the black/yellow wire at the small white plug at the Lead coil assy and still no spark.

I see nothing in your post that was strange. Just put in a new battery, didn't cross the positive with the negative battery lead.

YOu should have had spark. You have 12v on the black/yellow wire. The other wire puts out a 5v signal that comes and goes to fire the coil assy.

Sure the CAS plug is still on??? Crank Angle Sensor has a small white plug. If you have not messsed with it there is no reason to think it has come off. Got a spare ECU laying around??

You might ring out the wiring from the cas to the ECU at the ECU. https://www.rx7club.com/forum/attach...&postid=580160

It shouldn't come to that. Is there any *event* that happen when swappiing the battery out??? Crossed terminals???

 

How have you been checking for sparK??? You might try to pull all the plugs to get the motor to rotate pretty fast (and take a load off the starter), and lay Both of the LEAD plug wires close to a good ground (strut tower nuts and bolts work fine) and spin the engine and look for spark.

I don't see any reason for it to suddenly not spark, assuming it was sparking prior to the starter/battery replacement.

 

canged ecu tring to get rid of short so i guess that one is no good. will try putting old one back in.get back to you guys tomorrow.

 

well it was raining hard last night so i didnt bolt it down but hooked up the old ecu and still no spark??? only other things done was racing beat main and alt. pulley installed and crankangle sinsor was removed to get front cover off. but removed and installed by instructions or by the manual.

 

pulley holes only fit on one way for 86,88 main

 

no crossing of poss and neg.

 

Ah. You solve your own problem. The cas. Its installed wrong.
But before getting into that......do this......remove the cas.Leave its plug on. Now leave the sparkplug wires on, but remove one of the LEAD coil wires and let it just rest in the bore of the coil assy.

Now turn the key to ON.

Now spin the cas by its bottom gear in the same direction it turns when its being turned by the engine.

Did you see spark at the wire that is resting in the lead coil bore?????? Say yes.

Later. Gotta go. I'll be back later.

 

ILL TRY GET BACK TOMORROW

 

will try that and get back with you tomorrow.

 

that didnt work. turned key to on pulled cas. pulled wire from lead coil left in assy. turned both ways to make sure but still 0. guess that means coil??

 

No. To me that means the ECU isn't putting out. I was hoping that the only problem was the cas being off enough to keep it from starting.

I'm as puzzled as you are about why it does not start. You have 12v on the black/yellow wire at the small white connector at the lead coil. All it needs now is the ECU to trigger the coil/ignitor.

Is there the smallest chance you can put your ECU in another vehicle to see if it's bad? Another RX of the same model year?

An outside chance.....is your lead coil assy still grounded to the chassis? It won't work without being grounded to the chassis. That's not likely the problem. The Trail coils alone should be able to start the car. REAlly hard to believe both coli assy went south.

Personaly, if I was lost like this, I'd go to the ECU and ring out the cas through the plug at the ECU to see if the wiring was good and the coil assy inside the cas were good. Then go to each wire on the ECU to see what is missing.

You refered to a SHORT you were trying to rid yourself of. What short??? You real sure you have 12v at the black/yellow wire at the small, white, two wire plug at the LEad coil assy? I'd check again.

 

You don't have to do all the wires. If you could just check 1F, 3I, 3J, 2A, 2C, 2R, 3A, 3C, 3G those are just straight out 12v or ground wires. It'd give us a clue.

Just pull all three plugs off the ECU and put a meter to ground and check those wires on the harness plug for voltage or ground.

 

Heck. Mail me one of those ECU and I'll put it in my car and see if it works or not. I'll even pay the postage.

 

Is that from the FSM? I haven't had a chance to read it yet.