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jeffs9146 jeffs9146 is offline
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Join Date: Nov 2010
Location: Discovery Bay, ca
Posts: 269
Quote:
Originally Posted by jchris View Post
Hello all, I have been helping a neighbor with his 82 SC. I have an 83 that I have mostly sorted out so he asked me give it a shot. He told me it began running rough suddenly and he stopped driving it. Here is what I have found.

The frequency valve is not working. So I began the chain of investigation as is well travelled on this board.

Test were conducted with the fuel pump relay jumped.

The O2 sensor relay gets power, powering 85 and 86 causes 30 and 87-87b to close. 30 gets 12v. We tried a new bosch unit with the same results. (it is a good one at least)

I cleaned the jetronic connections and inspected for cold joints on it's circuit board. Nothing obvious. I will be swapping in my box next to see if that does it.

In the engine bay.

On the 12 pin harness connector pin 4 gets 11.38v with the o2 relay in, and with connector jumped.

The F.V. has a resistance of about 3 ohms (2.7)
The F.V. wiring has continuity to the firewall connection. (pin 1 and 4)
The F.V. clicks when 12v is momentarily applied.

If it is not the jetronic box, what else can I check? I understand that the controller pulses the ground for the F.V. where can I check that the controller has a good ground?

Thanks for your thoughts!!

Chris
Vacuume Leaks!!

Cracked air box
Leaky injector seals
Leaky vacuume lines

Fix all vacuume leaks first before attempting to adjust anything!!
Old 10-25-2013, 12:38 PM
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