[DMCForum] Re: Engine running half rich half lean.
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[DMCForum] Re: Engine running half rich half lean.


I agree with your diagnosis. I believe that not all of your injectors
are opening at the same time. The driving conditions you indicate,
plus the condition of your plugs seem to say this.

To my knowledge, the fuel distributor cannot output fuel so unevenly.
The metering plunger has slots cut into it...well I guess it could do
it if some of them were clogged but I've never heard of it causing
conditions like this.

Walt has reported similar problems due to injectors being clogged or
even new injectors that fail to open at the same time. Are these new
(to your car), or are they injectors that were in the car when you
bought it?

If you have the wherewithall, you can pull all of them and put them
in a wide-mouth jar, jumper the RPM relay and see which ones open and
when. (This test normally requires a injector test tube kit). If
you're totally broke, you could swap some injectors to the opposite
side of the engine, clean your plugs and observe how they wear again.
If the fouling pattern changes, then it's your injectors.

Or, for a reasonable $39.00 per set of 6, you can send your injectors
off to John Hervey and he'll send you a set of 6 used, but sonic-
cleaned and tested injectors. If you do that, make sure your tank,
pick up screen, and filter are clean so you don't gunk up the new

Hope this helps,


--- In DMCForum@xxxxxxxxxxxxxxx, Enid/Jeremiah
<hispanicangeleyes@xxxx> wrote:
> This is a unique problem.  When I start my car now, the engine will
run half lean and half rich.  The driver's side (4,5,6) all run rich
(spark plugs are charcoal colored), and the passenger side (1,2,3)
are lean.  The mixture screw has been adjusted properly, and these
sparkplugs have been replaced recently.  I assume the fuel
distributor sends fuel out equally, so I'm pretty sure the problem
doesn't lie there.  Could it be dirty/faulty fuel injectors?  I'm
kind of lost on this one. 

>    The car does something else unusual.  The engine will idle fine
when cold, but as the car warms up, the idling becomes very erradic. 
It will "jump" around when in drive or park.  Don't get this confused
with high idling or idling up and down in a cyclic motion - this
idling goes fast then slow and repeats this pattern very rapidly. 
It's very uneven and just all over the place.  It almost sounds like
the car will literally die when sitting at a stop light or a traffic
light.  When this idling problem occurs, I get alot of "spitting and
sputtering" when going from a dead stop to acceleration.  After it
spits and sputters for about 3 seconds, I get a sudden burst of
acceleration (almost as if one of the cylinders isn't opening, and
then WHAM! it opens all of a sudden)  The car will do this generally
around the time the cooling fans on for the first time, and then
after about 10 minutes the idling is perfectly normal.  When the
idling is normal, there is no more "spit and sputter"
>  either; the car runs completely normally.  Any ideas anyone?
> ---------------------------------
> Do you Yahoo!?
> Yahoo! Search - Find what you're looking for faster.
> [Non-text portions of this message have been removed]

Yahoo! Groups Sponsor

Yahoo! Groups Links

Home Back to the Home of PROJECT VIXEN

Copyright 2006 ProjectVixen.com.  All rights reserved.

Opinions expressed in posts reflect the views of their respective authors.
DMCForum Mailing List Archive  DMCNews Mailing List Archive  DMC-UK Mailing List Archive