'95 Q cranks but doesn't start.

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NextG50
Posts: 35
Joined: Mon Mar 15, 2021 9:41 am
Car: 1995 Infiniti Q45t
Location: Long Island (New York)

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My 1995 Q will crank over fine but won't start. It was running fine when I last drove it a month or 2 ago. I've been overseas since May and the car has been sitting for all that time. It cranks over fine and I hear the fuel pump prime when I put the key in the on position. I've never had this issue in the past and the car has always started quickly until now. I'm about to go pull off the decorative covers to check for spark, but that's going to be a total pain in the a** because the throttle body, AC refrigerant lines, and ABS module are in the way. Are there any common issues that cause this? I feel like I'm missing something.

When I leave the car sitting for long periods of time I disconnect the negative terminal on the battery as to not run it down.

In the past I've had issues with the MAF sensor due to cold solder joints.

Any help would be appreciated.


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NextG50
Posts: 35
Joined: Mon Mar 15, 2021 9:41 am
Car: 1995 Infiniti Q45t
Location: Long Island (New York)

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I sprayed starting fluid into the intake and it still won't start

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VStar650CL
Technical Expert
Posts: 12041
Joined: Thu Nov 12, 2020 1:25 pm
Car: 2013 Nissan Altima 2.5 SL
2004 Nissan Altima 2.5 S

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Spark is next, but check your ignition and start fuses before you go pulling stuff apart. It wouldn't be the first time something zapped after being reconnected.

I dunno if anyone had access to the vehicle in your absence, but if so, make sure nobody hammered a potato up your tailpipe or something dumb like that.

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NextG50
Posts: 35
Joined: Mon Mar 15, 2021 9:41 am
Car: 1995 Infiniti Q45t
Location: Long Island (New York)

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****UPDATE****

It was the ECCS relay!! I was getting no voltage and the common line for the coils which led me back to the ECCS relay. On the bench it switched fine but under load it wouldn't switch terminals 3 and 5 which supply the coils. I temporarily jumpered out the relay and lo and behold she started right up!

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VStar650CL
Technical Expert
Posts: 12041
Joined: Thu Nov 12, 2020 1:25 pm
Car: 2013 Nissan Altima 2.5 SL
2004 Nissan Altima 2.5 S

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The ECCS Relay is set up such that the ECM has to turn itself on. It's arranged that way so the ECM can wake itself up to check fuel tank evap integrity while the car is parked. Since the relay worked on the bench and the car woke up when you jumped it, that means the relay has power, and since the coil and one secondary throw operate off the same fuse, that means power isn't the issue and chances are the ECM or the wiring is the culprit, not the relay. The relay coil will have constant battery power on one side (check which with the relay removed), then the ECM grounds the other side to turn it on. So, with the relay installed, try jumping ground to the pin on the relay which connects the coil to the ECM (that will be the coil pin which doesn't have power when you check with the relay removed). If that wakes the car up, it means the ECM can't (or is refusing to) turn on the relay.


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