Well I disconected the bat. for approx. 10 min, hooked it back put in the jumper wire turned the key on and get a code 12. This is a good thing??? But when I have the jumper wire in and turn the key on the fan turns on also. Turn the key off remove the jumper, turn the key on and the fan (cooling) does not come on just when the jumper is in.
This did the same thing when I first checked the codes (the fan came on when I had the jumper on and the key) Still no spark new coil what else could cause no spark?? There is a big discount on one of my fiberglass aerowings that I advertise on this site (GT Auto) for the man that solves my prob!

 

88,
Code 12 is the response code. Is ok. With the jumper in and key forward, fan should come on. Is ok. Start car w/ jumper in? Is bad. This could harm the ECU.
That said, I have not seen that happen alot. I am assuming that you have had the no spark problem before you tried turning over the motor with the jumper in. Do you have a stock set up? An alarm? Post up some info to look over. If it is a stock set up, the first thing I'd do is yank the ignition module and go have it tested at the parts store. Good luck

 

someone quote me if I'm wrong but a few years back I read (forgot where) that you could run down the road with the jumper in and the engine light would flash a certain amount of times (fast or slow) depending on how rich or lean the car was running. This was strictly to determine if the engine was running rich or lean. I actually did this and never had any problems with my ECU. Of course don't try this until someone backs my statement up. It did show that I was running slightly rich which of course can be determined by pulling a spark plug.


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1988 TA 300+hp 350 w/ TBI and Holley TB unit, Holley projection intake,
WC T-5, 3.42 gears w/ Auburn posi. MSD 6A, edelbrock TES headers, dynomax 3" cat and cat-back system, ACCEL coil, polyurethane bushings all around, aluminum driveshaft, Mr. Gasket open air cleaner.

1993 S-10 w/ 4.3L V6 TBI, slightly bigger cam, Mild polish job and 3 angle valve job on heads, Edlebrock TES headers, Dynomax cat back, MSD 6A, ADS chip

2000 Kawasaki KX 125

 

BB88, you jump it after you start the car so you can see if you are running in open or closed loop.

 

88,

First things first. Your ECM appears to be acting normally. The code '12' is for no distributor reference pulses, which means the distributor is not turning. This is normal when the engine is not running. (I know - no ****, Shirlock!) Just establishing that a '12' is normal.

The fan(s) should energize when the ALDL is jumped and the ignition is turned on. That is completely normal.

And BadBird88 is correct - you can install a jumper AFTER the engine is running to force Field Service Mode. This can help determine ECM operating mode and mixture adjustment.

The main point is that you should never crank the engine with the jumper installed. That can completely "flip out" the ECM RAM or cause permanent damage. At least yours only "flipped" and you were able to clear it.

As far as the lack of spark, test for spark at the coil instead of at the plugs. Remove the coil secondary wire and hold it near a ground (within 1/4") while an assistant cranks the engine briefly. This eliminates the distributor cap, rotor, plug wires, and plugs from the circuit. If there is spark present your problem is in the other secondary components, like cap, rotor, plug wires, or plugs.

If there is no spark at the coil tower, measure the coil resistance. The primary winding should be about 0.2-3.0 ohms, and secondary winding should be about 6,000-30,000 ohms. If the resistances are within range, make sure there is 12VDC at the HEI '+' terminal in the base of the distributor when the ignition is on.

While the cap is off, check the reluctor and pickup coil. The pickup coil should measure between 500 and 1,500 ohms (out of circuit) and the reluctor should have no visible damage or cracks. If no components show damage or fail the tests, remove the HEI amplifier/switch module and have it tested at a local auto parts store. Many offer a test free of charge.

If the amplifier module is functioning, disconnect the EST bypass connector and try starting the engine. If the engine starts, the EST and/or ECM may have faults.

If there is voltage at the '+' terminal and all the above items are functioning, you should be running - or at least producing spark.

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Later,
Vader
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"Make Me Bad"
Adobe Acrobat Reader 4.0

 

Could someone tell me more about the "Field Service Mode"? I'd like to find out if my car is rich or lean and that's maybe what'd cause my studdering and hesitation...plus that lovely backfire through the exhaust...(leaning towards fuel pump now days)

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89 IROC-Z 350 TPI

-Flowmaster Catback
-Performance Resource Chip
-700R4 (Rebuilt) Too much done to actually list
-K&N Airfilters
-Ported Plenum
-2.77 Gears (not much to brag about but eh, its there)
-Future:
-383 Stroker?

 

Branz,

Field Service Mode

On the OBDI ECMs, you can jump 'A' and 'B' terminals on the ALDL while the engine is running.

WARNING! This must be done after the engine is running. This is called "Field Service Mode" and will not harm the ECM.

If the ECM is in Open-Loop mode, the SES light will flash rapidly, about 2 ½ times per second. If it's in Closed-Loop mode, it will flash about once a second. When in Closed Loop mode, flashing less than once per second indicates the ECM is enriching the mixture above the 128 count base line. Flashing more than once per second indicates the ECM is leaning the mixture below the 128 base line.

A 10K or 3.9K resistor (don't remember which one) put between ALDL terminals 'A' and 'B' forces the ECM into Backup Fuel mode. This mode forces the ECM to use predetermined fuel calculations in the ECM PROM instead of the learned inputs in active RAM. This is commonly referred to as the "Limp Home" mode of operation.

(If anyone remembers the resistance to force Backup, please pipe in.)


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Later,
Vader
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"Make Me Bad"
Adobe Acrobat Reader 4.0

[This message has been edited by Vader (edited October 19, 2000).]