plug question

M

markg

NAXJA Forum User

Location

nj

• Jan 19, 2010

• #1

91 xj 4.0.
ive just replaced just about everything with my no start issue.now it starts but idles and runs like it has a bad miss.the plugs are brand new.i pulled them after running for a while and all look brand new except the rear #6 one which is black.i pulled the plug put the wire on and grounded it and it seems to be firing fine.
any ideas?

 

B

birchlakeXJ

NAXJA Forum User

Location

Melrose, MN

• Jan 19, 2010

• #2

If the spark is strong at the plug, you might have a problem with either the fuel injector not firing properly or a problem specific to that cylinder.

Verify the function of that injector (noid light, check resistance, swap, replace, etc) and running a compression test to see if cylinder #6 varies from the rest of them would also be of value.

 

ehall

NAXJA Member

NAXJA Member

Location

Southern Maryland

• Jan 19, 2010

• #3

#6 injector might be leaking

 

MJR

NAXJA Forum User

Location

Costa Mesa, CA

• Jan 19, 2010

• #4

Injector swap to see if it changes cylinders. I had one in Moab that the injectors 5 and 6 had rust packed in them and it was pretty obvious when I pulled them out to swap test.

 

joe_peters

NAXJA Forum User

Location

Grants Pass, OryGun

• Jan 19, 2010

• #5

birchlakeXJ said:

If the spark is strong at the plug, you might have a problem with either the fuel injector not firing properly or a problem specific to that cylinder.

Verify the function of that injector (noid light, check resistance, swap, replace, etc) and running a compression test to see if cylinder #6 varies from the rest of them would also be of value.

Click to expand...

x2, test your way to the answer.

 

W

winterbeater

NAXJA Forum User

Location

Royal Oak, Michigan

• Jan 19, 2010

• #6

Compre$$ion test first, before you waste time and money.

 

M

markg

NAXJA Forum User

Location

nj

• Jan 21, 2010

• #7

thanks for the info.i put a new plug and wire on #6 tonite and all seems well.