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-   -   91 fc na won't start (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/91-fc-na-wont-start-1105468/)

David Jones 09-16-16 09:43 AM

91 fc na won't start
 
Ok guys I've posted this before on an old thread thinking I found the issue and still havnt. The car wants to start but it just wont.
Lead coil pack has spark but it's weak.
Trailing coil pack has good spark.All the plugs are getting fuel.
I found as bad wire on the fuel pump relay and fixed that last night.
My pressure sensor vacumm line runs directly to the top nipple in the upper intake mani. Is that ok.
Egr is deleted so that sensor is put in the switch solenoid spot. And the top left is capped. Any help is needed thanks guys.

satch 09-16-16 10:07 AM

An S5 doesn't have the EGR. When was the last time the car started? Have you checked compression? Have you deflooded the engine (press all the way down on the throttle while starting). Have you tried to start the car with starter fluid.

David Jones 09-16-16 10:18 AM


Originally Posted by satch (Post 12107191)
An S5 doesn't have the EGR. When was the last time the car started? Have you checked compression? Have you deflooded the engine (press all the way down on the throttle while starting). Have you tried to start the car with starter fuid.

Oh I thought it did. It's been about 3 months since it's last start. Compression checked out, I've deflooded it. New plugs. And it started once on starter fluid and after that it tries but wont.

satch 09-16-16 10:25 AM

Which wire did you fix at the fuel relay. The Blue wire which runs to the pump powers the pump thus it should have voltage w/key to start. Does it. The Blue wire at the circuit opening relay is basically the same wire thus it too should have voltage w/key to start (this wire runs to the fuel relay under the air box).

David Jones 09-16-16 10:35 AM


Originally Posted by satch (Post 12107201)
Which wire did you fix at the fuel relay. The Blue wire which runs to the pump powers the pump thus it should have voltage w/key to start. Does it. The Blue wire at the circuit opening relay is basically the same wire thus it too should have voltage w/key to start (this wire runs to the fuel relay under the air box).

I fixed the blue wire at the connector at the fuel pump connector.

satch 09-16-16 10:37 AM

Have you verified in any manner that the pump is working?

David Jones 09-16-16 10:38 AM


Originally Posted by satch (Post 12107209)
Have you verified in any manner that the pump is working?

Whenever I turn the key to on I can hear it running and the plugs are getting fuel.

satch 09-16-16 10:43 AM

What makes you think the spark is weak at the lead coil. And when you got the car started w/starter fluid did it keep running or die out rather quickly?

David Jones 09-16-16 10:46 AM


Originally Posted by satch (Post 12107212)
What makes you think the spark is weak at the lead coil. And when you got the car started w/starter fluid did it keep running or die out rather quickly?

Whenver I checked spark, the sparks were more faint and not as rappid as the trailing. And it died after 5 seconds of running on starter fluid.

clokker 09-16-16 10:49 AM


Originally Posted by David Jones (Post 12107186)
My pressure sensor vacumm line runs directly to the top nipple in the upper intake mani. Is that ok. .

Hmmm, I don't think so...it should go to the lower manifold and also should have a restrictor pill in the hose (if you replaced the hose it may be gone).

Not sure that would prevent the engine from starting though, my pressure sensor was bad and the car ran but threw a code.

satch 09-16-16 10:55 AM

The color of the spark should be Blue if strong and more Orange if weaker. Have you ohmed out the plug wires on the lead coil.

David Jones 09-16-16 11:17 AM


Originally Posted by clokker (Post 12107215)
Hmmm, I don't think so...it should go to the lower manifold and also should have a restrictor pill in the hose (if you replaced the hose it may be gone).

Not sure that would prevent the engine from starting though, my pressure sensor was bad and the car ran but threw a code.

I thought I seen that it could. Hmmm

David Jones 09-16-16 11:18 AM


Originally Posted by satch (Post 12107220)
The color of the spark should be Blue if strong and more Orange if weaker. Have you ohmed out the plug wires on the lead coil.

The spark is blue it's just not rappid. It's like the power is going in and out. I just picked up a volt meter today so I'm going to ohm it tonight.

Acesanugal 09-16-16 11:27 AM

Meter fuse? Tho I thought that cut power to the coils..

David Jones 09-16-16 11:30 AM


Originally Posted by Acesanugal (Post 12107234)
Meter fuse? Tho I thought that cut power to the coils..


Meter fuse? What do you mean?

satch 09-16-16 11:37 AM

If you have voltage on the B/Y wire at the lead coil ,which you do, then your fuses are good. And your plugs might be fouled even though they are new (you can dry them out w/a blow dryer or heat gun). Also, the starter needs to turn at a certain speed to start the car, the battery needs to be fully charged as well.

FührerTüner 09-16-16 11:38 AM

Did you clean the clogged injectors you mentioned in your other thread?

Does the car still start with starter fluid?

satch 09-16-16 11:53 AM


Originally Posted by Fuhnortoner (Post 12107238)
Did you clean the clogged injectors you mentioned in your other thread?

Does the car still start with starter fluid?

Speaking of the injectors you stated in your last thread that the upper injectors were clogged. How did you come to this realization. Also, by upper injectors you are referring to the accessible ones because those are the secondary injectors and they are not used to start or idle the car.

David Jones 09-16-16 12:08 PM


Originally Posted by satch (Post 12107245)
Speaking of the injectors you stated in your last thread that the upper injectors were clogged. How did you come to this realization. Also, by upper injectors you are referring to the accessible ones because those are the secondary injectors and they are not used to start or idle the car.

The secondary were clogged and I went ahead and installed all new so I could eliminate that. It only started on starter fluid one time for 5 seconds.since then its tried starting but just wont fire.

satch 09-16-16 12:11 PM

But how did you know they were clogged and how do you know what shape the primary injectors are in? Also, are you certain the CAS was stabbed correctly?

And in your other thread you mentioned the compression was checked and it was good but you don't have the numbers to support this.

David Jones 09-16-16 12:15 PM


Originally Posted by satch (Post 12107253)
But how did you know they were clogged and how do you know what shape the primary injectors are in? Also, are you certain the CAS was stabbed correctly?

I ffigured they were clogged because the trailing plugs wernt getting fuel. I changed the primary and secondary and now all 4 plugs are getting wet with fuel. And no I'm not certain the CAS was stabbed right. How would I check that?

satch 09-16-16 12:26 PM


Originally Posted by David Jones (Post 12107255)
I ffigured they were clogged because the trailing plugs wernt getting fuel. I changed the primary and secondary and now all 4 plugs are getting wet with fuel. And no I'm not certain the CAS was stabbed right. How would I check that?

Could you pull the plate off the top and take a pic if it isn't too much trouble? Look at post #102 for an accurate pic.

https://www.rx7club.com/2nd-generati...-887302/page5/

FührerTüner 09-16-16 12:35 PM

Are you running the correct impedance injectors?

David Jones 09-16-16 12:44 PM


Originally Posted by satch (Post 12107258)

Could you pull the plate off the top and take a pic if it isn't too much trouble? Look at post #102 for an accurate pic.

https://www.rx7club.com/2nd-generati...-887302/page5/

Yes i can take a pic when I get home from work. Thanks man

David Jones 09-16-16 12:45 PM


Originally Posted by Fuhnortoner (Post 12107261)
Are you running the correct impedance injectors?

Yes they are factory size injectors.


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