Recently car's been dieseling after i shut it off. It'll still sorta spudder/run for 2-4 cranks, and it aint healthy to say the least. Trying to figure it out.

Thermostat is fine and car's temp is fine.
Gas is fine(multiple tanks) 94oct
Turned down timing a bit, doesnt seem to help
idle is fine

Two days ago, i checked my spark plugs, and cyl #1 had white carbon? buildup(powder like) on TOP of the spark plug, where you put the socket on to remove it, not on the actual arcing point.

Any idea's?
Any help appreciated.

 

The old carburetored cars would do this because as long as the engine was turning the carburetor would feed gas. Fuel injection cured this. Turn off the ignition and the injectors quit working - unless they are leaking.

 

yep, my thought as well, leaky injector(s)

 

Installing new fuel pressure gauge on the fuel rail today since old one took a crap, then gonna try a different fpr, and gotta check out injectors. I'll report back later.

Thanks for the info

 

Have you checked the fuel pressure first? That would probably tell you whether you need to change that or not.

 

If the fuel pressure goes to nuttin when you shut if off, you have the answer.

 

But if its that bad that the pressure in the rail drops rapidly wont he also have been complaining of hard starts?

 

Yes if the fuel pressure was low enough, he would have hesitant starts most likely.

Also to the OP, if you have stock injectors you can get the seals/o-rings from any local autopart store. Pick one (Ie autozone, oreillys etc...) and I'll give you the part numbers. You can get all 4 sets, for cheap

 

The starts havent been any different then ever,... always takes a couple cranks, and its always been like this. Injectors are about 4months old, FIC 1450's, and this started happening couple weeks back, but it just got worse and worse as time went on.

Recently installed new plugs, and the hard line running above the fuel rail, i removed it while back and replaced it with just a fuel hose, so i can run it behind stuff to clean up engine bay. Well i reinstalled that stock "hard line" and its a little better, but it still happens.(today after tuning car off after a 15min ride), it still turned over once, so problem isnt fully cured.

Tomorrow gonna try a different FPR, and a carb cleaner, one at a time and see what fixes this, if it gets fixed.

 

Sorry Evom mobile doesnt show signature, i posted before I saw you signature. Also carb clean what? I dont think blasting carb cleaner in the TB, while the throttle is WOT (ie engine off or on), is such a good idea. If thats what you were thinking. You may create more problems this way..

 

yea, didnt do no carb cleaner
it got better, and last two days its been ****ty again... turned car off, and it practically ran for a second still, ugh. Time to check injectors for leaks.

 

Stock ecu or aem?

 

aem

i've been on aem for almost 3 years
just started recently

 

Did you ever figure out your problem? I'm having the same problem. I have a 2005 Evo 8, with a Series 2 AEM, and FIC 1450cc injectors. I have the same dieseling problem also. I also had the same problem on the 1650cc FIC injectors too. My fuel pressure drops after I drive the car for a little bit. On cold start-ups the fuel pressure is where it should be, which is 40psi. But after I drive and come to a stop my wideband is at 15-17afr. And when I check my fuel pressure, its below 30psi. Sometimes around 25psi. I forgot to mention that I am speed density too, if that helps? Any suggestions?

 

Last time I ran into an issue like this it was with a car that wasn't a mitsu, and was bone stock, the injector driver in the pcm was going bad, any chance the aem computer is going bad?