Nissan Forum banner

1 - 5 of 5 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter #1
I have a 1981 280zx non turbo inline 6 that starts and idles good. After a few minutes of idle the engine will start missing and running rough. It will eventually cut-off. It will start back eventually and it seems to be flooding. The spark plugs are smotty (new plugs and wires installed). I have changed the CTS between cylinder 5 and 6, checked all the injector signals and cleaned the Mass Air flow sensor. The fuel pump is a brand new Nissan pump that is producing 30 psi during this condition before the pressure regulator. I have installed a new fuel filter and also temporarily removed the catalytic convertor and the problem still exists. It seems to lack power at acceleration all the time. Any ideas will be greatly appreciated.
 

·
Sup Mod keeping the peace
Joined
·
6,165 Posts
There's a good chance that one or more fuel injectors are defective; one or more probably leaking which may be causing the rough running and fouling the plugs. Easy enough to replace. If you plan to replace them, don't buy them from Ebay; a lot of them are from China and are junk. Good places to buy re-manufactured OEM injectors are RockAuto, AdvancedAuto, and AutoZone. With re-manufactured OEM parts usually (not always) refers to a part that, for all practicable purposes, has been completely re-manufactured to the standard of a new OEM part. With rebuilt parts, rebuilders will use a vehicle's old part and replace just the worn components. If the vehicle's old part cannot be rebuilt because it is too worn, they will use a part from another vehicle (referred to as a 'core'). If a core is used, than they will replace only what is needed in the core. So to summarize, new or re-manufactured are the best to buy. A rebuilt part may still be defective or DOA when you're ready to use it.
 

·
NF Mod/Nissan Master Tech
Joined
·
9,341 Posts
"Back in the day"....when I was just a young lad working in the Datsun dealer across the street from my high school...the most common cause of that symptom would be a bad ignition module (the black plastic box that's bolted to the side of the distributor). The module would be fine when it was cold, but, once it got heated up, it would start causing an intermittent spark to finally a no spark issue. Then, when it sat and cooled off, it would work fine, again. If the fuel injectors were leaking into the cylinder, then I would suspect hard starting issues due to flooding of one or more of the cylinders. Usually when the fuel injectors would leak on those "L" motors, they would leak externally or at the hose, great for creating fires under the hood! So, before spending a lot of money on new fuel injectors, I would get a fuel pressure gauge and do a fuel pressure leakdown test to make sure they are actually leaking. Also, make sure that the diaphragm inside the fuel pressure regulator hasn't split and is causing gas to get sucked into the intake through the vacuum hose.
 
1 - 5 of 5 Posts
Top