So recently my Max has been dieseling (for those of you who don't know, car runs very roughly after being turned off) Changed the spark plugs and so far so good, but would Seafoam be a good idea? Or does anyone recommend anything? I was running really rich after my 00VI swap so I'm thinking there may be some carbon buildup glowing red. What doesn't make sense is the fuel injection. With the key off, the pump should stop. Apparently, it isn't. Any ideas for that?

As for the starter issue: I can put the key into the crank position but the car won't start cranking until after a minute or two. It's not a starter or alternator issue. I think it might be related to either the fuel pump or grounds. I don't see why the grounds would be faulty, though.

Any help greatly appreciated.

 

Your second problem may very well be the ignition switch.

When it diesels, do you have any indicator lights lit on the dash? Or is acting as if the key is completely out?

 

How would I test for the ignition switch?

When it diesels the key is completely out of the ignition. It would last only 10 or 15 seconds but the other day the only way I got it to stop was by letting the clutch out.

 

If you've having those sorts of problems, it generally turns out to be the ignition switch. $30 and 15 minutes, worth a shot.

 

No, no indicator lights. Ignition switch at the dealership? What exactly is it? The entire key housing?

 

No, it's the electrical unit that sits behind the lock cylinder, it houses the actual contacts that determine OFF, ACC, IGN, and START.

When I searched a while back, it was actually the cheapest at the dealer, and they were the only ones to have one in stock. ~$30 IIRC.

 

Alright. Thanks. I'll swing by there tomorrow.

 

No luck. It helped a little, but there is still a delay of about 10 to 15 seconds.

 

Dieseling or run on happens when the combustion chamber is hot enough to ignite the a/f mixture after the spark has been turned off. What is very odd about this happening on a Maxima is that our fuel system is off when the key is turned off. There should be no injector pluse, so no fuel being dumped into the engine.

Something tells me your ecu might have a mind of it's own here. Find the source of the run on and I would guess your other problem will resolve itself as well. I'd look closely at the ecu.

 

What I'm thinking is that the injectors are staying in an open loop and the fuel still in the lines is continuing to combust. I don't know. I'm worried more about the starting since it hasn't dieseled with the new plugs in.

 

i am a fan of seafoam. it works wonders on carbon.
i with the key off there seems to be know way for the injectors to be on. maybe there leaking? or maybe your pulling fuel from the evap system some how.
to be sure its not the injectors staying on popt the hood and pull the batt cable, if you can do it fast enough