@ Jon -
re: Do you mean #5 and #7? (You mentioned #6 twice)
I started to do the trace on the passenger side, then went to the other side and that was the order or re-ordering of the ignition cables. So looking at the firing order 3 & 6 are next to each other and 6 & 5 are next to each other and the engine did not shudder much from this mis-wiring (power seemed lower though). After correcting the wiring it drives better but still has a slight shudder as if a fault 27 related and/or bad ignition cable (intermittent).
Maybe it needs new cables. It has BWD low resistance (solid wire) ignition cables. Ohm meter does not turn up any bad cable (cold).
When it had the high resistance carbon cables it got better MPG, wonder why? Which are better?
It's currently getting ~14 mpg and when it had the OEM carbon core wires it got 18 mpg.
I don't know what I can do for Fault code #27 as far as checking the FI harness or function. Have any of you conducted repairs on this section?
@ Jim Zito + David C. Wilker Jr.
+ Mike Sykes
Sorry it should have read N.O.
I think the old way was NOx for Nitrous oXides
related: http://3.ly/tcX
@ David C. Wilker Jr.
re: If I had to guess, I
would say that your EGR valve is stuck shut.
It was replace less than 20k miles ago, can it go bad that quick?
I love your quote: If we cannot afford to take care of Veterans, then we should stop making them.
original msg:
5.2L V8 4x4 '94 Gen 1 with 175k miles on Odo
last smog test 12k miles ago - 2 years prior
Everything passed with good margins
NOx was 250 / 491 ppm max
HC and CO - very low.
Prior to getting the passing scores I replaced the EGR valve,
CAT, ignition parts, TP sensor, O2 sensor, thermostat, Coolant sensor
and coolant. All of the parts were replace within 5,000 miles of that
test.
This time I only replace ignition parts and oil & filter
NOx results measured was ~ 900 / 491 ppm - thus failed the smog test.
I get to go back in 60 days for a free retest.
In the interim I found out the gasket under the air filter hsg.
was cracked and I replaced it, also the hose from the PCV to vac port
got replaced and the gastank cap that had cracks in the seal.
Then I found it had mis-wiring in the ignition wires at the cap.
#3 and #6 were reversed on one side and
#5 and #6 reversed on the other bank.
(firing order 1-8-4-3-6-5-7-2)
Fault codes are: 12 and 27
I believe 27 is an intermittant possibly in the Fuel Injection harness but have no idea how to repair it.
Can any of the above cause the high NOx?
Could permanet damage occur to the CAT due to the mis-wiring?
Any comments/help appreciated.
ron
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