83 280zx non turbo 5 speed runs rich. heavy black smoke/ soot coming from exhaust. rough idle before warm up. how do i fix this problem?

280zee
0

Asked by 280zee Dec 03, 2011 at 03:55 PM about the Nissan 280ZX

Question type: Maintenance & Repair

83 280zx 5 speed, non turbo coupe. car has a rough idle at start up which smooths out as car warms up. exhaust is very black and sooty. car is running rich. spark plugs also covered in black sooty carbon. car is stock except for cold air intake. what is causing this problem? what should i check or adjust? thanks.
rod

2 Answers

OrLackThereof
1,385

Need a little more information...mainly, when did this start? Did it start after you put on the Cold Air Intake? If yes, check any related sensors first for condition and proper connection... MAF and IAT..... very important to mixture control. If there's no connection with the Cold Air Intake, there's a few possibilities and it would take some diag work to narrow it down.... Stuck EGR valve is one possibility. Another possibility is if the fuel pressure regulator operates on vacuum with a diaphragm, sometimes the diaphragm will blow which will increase the fuel pressure and also allow fuel to be sucked through the vacuum line directly into the intake. I'm not familiar with the fuel delivery system on the old Nissans......I'm assuming it's an early generation fuel injection setup though...?

83d280zxturbo
10

on these late models check all your vacuum lines they are notorius for hardening around the nipple hook ups and cracking there i had the same problem on my 83 turbo if left to long it can cause damage to the engine one trick is get some rubbing alcohol and start car pour some of it in a small cup 4oz. about disconnect a vacuum line to the intake manifold leaving it connected to the manifold allow the hose to slowly suck it in with out stalling the engine and plug it with your thumb this will clean you maybe running to cold of spark plugs

Your Answer

Add photo

Related Questions

Search Nissan 280ZX Questions

Nissan 280ZX Experts

#1 Albaro Villegas
Albaro Villegas
Reputation 30
#1 dandyoun
dandyoun
Reputation 30
#1 Jonpoon
Jonpoon
Reputation 30
View All

Related Models For Sale

Used Nissan 300ZX"
124 listings starting at $2,500
Used Nissan 240SX"
15 listings
Used Nissan 350Z"
104 Great Deals out of 1,739 listings starting at $5,950
Used Nissan 200SX"
25 listings
Used Nissan 370Z"
48 Great Deals out of 2,363 listings starting at $14,500
Used Chevrolet Camaro"
560 Great Deals out of 30,998 listings starting at $1,795
Used Nissan Altima"
1,501 Great Deals out of 85,532 listings starting at $1,000