97 Aerostar Timing Chain
#47
make sure OBDII PCM is going into closed loop when coolant temp goes over approx 155d F
record fuel trim levels, primary O2 sensor voltage swing min>max
also record timing, should be 10 BTDC at idle and increase to 28 BTDC at 2k rpm
pull wire from IAC, engine rpm should almost or completely stop
double check to make sure all sensors are connected
the 2 scanners I have
http://www.autoxray.com/product_detail.php?pid=94
http://www.autoenginuity.com/products-scantoolpalm.html
clearing codes with a consumer retail reader or scanner does NOT clear the KAM in the PCM of faulty sensor readings or failed component operation, we only have the technique of disconnecting the neg-- batt. lead for 5 minutes to dump old KAM memory parameters
record fuel trim levels, primary O2 sensor voltage swing min>max
also record timing, should be 10 BTDC at idle and increase to 28 BTDC at 2k rpm
pull wire from IAC, engine rpm should almost or completely stop
double check to make sure all sensors are connected
the 2 scanners I have
http://www.autoxray.com/product_detail.php?pid=94
http://www.autoenginuity.com/products-scantoolpalm.html
clearing codes with a consumer retail reader or scanner does NOT clear the KAM in the PCM of faulty sensor readings or failed component operation, we only have the technique of disconnecting the neg-- batt. lead for 5 minutes to dump old KAM memory parameters
Last edited by 96_4wdr; 05-07-2007 at 04:29 PM.
#48
Originally Posted by 96_4wdr
97 has OBDII which continually monitors for misfires and stores same with snap shot in memory at time of event, will tell you which cyl is misfiring...can be injector, plug, wire, etc.
OBDII scanner is a cost effective investment for all newer vehicles...will pay for itself in just a couple incorrect repairs or wrong parts
the auto manuf.s have such a large investment in OBDII CAN and it works so well that it will be around for at least the next 10 years
OBDII scanner is a cost effective investment for all newer vehicles...will pay for itself in just a couple incorrect repairs or wrong parts
the auto manuf.s have such a large investment in OBDII CAN and it works so well that it will be around for at least the next 10 years
I've had one about 4 months & it is definately an asset & will pay for itself over a short time. You can also reset the CEL & better software will calculate Engine load & HP, long & short term fuel trims, RPM, MPH, ECT, ACT, PW (Injector pulse width), O2 sensor voltage, AFR Dilution (with wideband O2 sensor only), ISDC (idle speed duty cycle) throttle position, Ignition timing, etc. You could have already made use of it so far!
ATB Aeroman.,
#49
#50
Okl, after tracing out the EGR system found that the one of the rubber hoses that connects to the carbon cannister (below the air cleaner) had fallen off. Hooked up and car ran great with no hesitation or missing for about 300 miles. Now i have a new problem. Daughter was driving the other day and when cold the idle was screaming like 2000 rpm. I unpluged the idle air soleniod and the idle dropped way down. Basicaly if you start it cold you now have to partially push the acccelerator down. Once it is warm it is fine. I was going to replace the idle air soleniod but thought I should check first. Is that a positioner or an open close valve? If it is a positioner I could understand how replacing it would fix the problem.
#51
it is a timed open closed valve that can be rapid variable timed opened by the PCM with variable timed DC voltage from the PCM
main stuck open failure is from dirt/PCV crud freezing piston
take off and soak in TB cleaner for an hour, often works and saves $$$$
also change PCV valve if older than 20k miles or loaded up with crud....do NOT try cleaning, the valve springs lose tension and the valve seat wears
main stuck open failure is from dirt/PCV crud freezing piston
take off and soak in TB cleaner for an hour, often works and saves $$$$
also change PCV valve if older than 20k miles or loaded up with crud....do NOT try cleaning, the valve springs lose tension and the valve seat wears
#55
#56
#57
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