ECU problem...improved!

Bernie Benz b.benz at
Wed Mar 26 07:30:21 EST 2003

You might explore sending your ECU into Ned at IA for a Stage III upgrade,
if he can also find and repair the problem.

> From: Barry Doolan <bdoolan at>
> Date: Wed, 26 Mar 2003 09:28:14 -0500
> To: 200q20v at
> Subject: ECU problem...improved!
> Thank you Alan Cordeiro for the suggestion to borrow 5 volts from
> another ECU pin to send to my Hall sender as a temporary fix for my
> ECU. Although no other pins deliver 5 volts, my mechanic installed a
> radio shack voltage regulator  from another pin to the Hall sender.
> It delivers the 5 volts fine but the amperage draw to the sender must
> be higher than the voltage regulator can handle. It gets pretty hot
> but works fine so far.  It will do as a temporary fix of getting my
> car started.
> I will have to bite the bullet and purchase another ECU. OUCH! Does
> anyone out there have a source? Are there any parts cars with a good
> ecu?
> Looking to replace within the next two weeks
> Barry Doolan
> 91200gt Burlington Vermont
> My 1991 200qt 20v has been having start problems over the past 2
> weeks related to a "Check Engine"signal. Car would start after a long
> wait (in the cold of Vermont), check engine light comes on after a
> short time, and then no start until another wait of hours. When
> brought inside in a warm shop it wouldn't start at all. Codes pointed
> to the Hall sensor but the culprit is now narrowed to pin 12 on the
> ECU which brings voltage to the Hall sensor. Voltage at this pin
> should be 5 volts but it only reads 1 to 1.2 volts. My mechanic
> connected a voltmeter to the pin at a time when the voltage read 5
> volts (car had been sitting for a day) and it started right up. On
> driving the car a short distance the voltage dropped to 1.2 volts and
> the check engine light came on. When he returned the car to the shop
> it would not start again.
> So, it appears to be a malfunction of the ECU? Has anyone had
> experience fixing this problem without replacing the ECU? If I do
> need to replace, who has a spare?? Mine is the original (I believe)
> stock ECU with no upgrades.
> I am off on a trip (flying not driving)until Thursday, but I still
> would like to see some responses on the listserve for me to read on
> my return. In the meantime anyone with a part or advice to my
> mechanic can reach Doug at constant at I am hoping to get
> this problem resolved. With  the maple sugar now running in Vermont
> the warm days will doom any more drives in my car until this is fixed!
> Barry Doolan
> Cambridge, Vermont
> Black 1991 200qt2Ov

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