On Mon, 02 Apr 2018 02:39:20 -0700, Gunner Asch
wrote:
On Sun, 01 Apr 2018 23:18:19 -0400, Clare Snyder
wrote:
On Sun, 01 Apr 2018 19:44:08 -0700, Gunner Asch
wrote:
Now any vehicle newer than 1997 doesn't even see a sniffer anymore.
If the OBD2 doesn't find a problem, you are GOLD. Depending on the
year you can even have either 1 or 2 monitors not set - so you can
sneak a surprizing amount of stuff through by keeping the tank either
full or below 1/4 tank, etc to keep the monitor from setting. Monitor
not set cannot report an error (such as a minor vapor emission leak,
or even sometimes a dead or dying catalyst. (my 2002 Taurus 4 cammer
has one empty catalyst and has gone as long as 6000km without turning
on a CEL)
Ive got a question for you Engine Mavins:
Moby Dick..the 1989 E350 van (just checked..odo shows 15,895.1
miles..wife has been driving it) has a flickering check engine light
when cruising down the road. No load..mostly on the flat and level at
about 45-65 mph.
NO codes..none..nada..nothing is showing up on my Acton OBD1 reader.
Says everything is hunky dorey. She passed smog just fine as well
about 6 months ago.
Any idea what to check?
Getting this 1988 F-150 to go with it..is interesting. Many of the
same parts were used, despite it being a 302. So I had no issues
doing a lil tune up last week during a couple evenings.
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Check the charging system. On some of the old EEC IV systems the
check engine will come on with bad charging system.
Its got dual batteries. Engine cranking and lights run from the
passenger side battery..all else runs off the drivers side battery.
Coach battery
Everything seems to be working fine.
The EGR position sensor on an '88 Ford will cause that problem, and
being "OBD1" - or technically EEC IV, it will not necessarily throw or
hold a code..
Check the connections on the EGR - also check to be ABSOLUTELY CERTAIN
there are no vacuum leaks in the EGR control system. Perhaps remove
the EGR valve and clean the heck out of it. The postion sensor may be
mis-reading the position, or the valve may actually be sticking
there is a second "starter solenoid relay" that engages the second
"accessory" battery when the engine is running...adding the second
battery to the first so that it charges. When engine/key is off..the
relay is not engaged and it does not connect the second battery to the
first..so if the second battery fails or runs down due to use..it
still allows you to start the vehicle on the first battery.
Put your 'scope on the alternator output and check to be sure the
output is constant. NOT LIKELY, but possibly the brushes are jumping
and the charge is intermittent - which on SOME vehicles will screw
with the CEL.
Could also be a bad ground wire (had that happenon Pontiac TranSport.
There are a **** load of grounds..both in the engine compartment,
under the dash and on the frame. I've cleaned/tightened all of them I
could find. No joy as of yet.
Thanks for the help btw. Much appreciated. Since John died..I've been
having to fix this stuff..and finding that he made a number of bad
calls and bad repairs. sigh.