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The tach doesn't show any RPMs and also the instrument light drops when cranking but the icons stay lit. The tach needle is barely visible so I am almost sure that it doesn't show RPMs.
I have replaced the bad caps (with good low esr tantalums) on the instrument panel PC board but the panel light will sometimes drop when temperature is high.
I have replaced the bad caps (with good low esr tantalums) on the instrument panel PC board but the panel light will sometimes drop when temperature is high.
I worry about the oscillation of DC regulators caused by the phase rotation which often happens when too low ESR capacitors are used.
As is written at the lower part of page 1 below. http://www.kemet.com/Lists/Technical...0Too%20Low.pdf
Last edited by Yamae; 05-20-17 at 09:01 PM.
Reason: To add a link
I worry about the oscillation of DC regulators caused by the phase rotation which often happens when too low ESR capacitors are used.
As is written at the lower part of page 1 below. http://www.kemet.com/Lists/Technical...0Too%20Low.pdf
Hi Yamae. Yes I understand the article as many years ago I was a power supply designer and had to worry about phase margin and stability. I did the very thing that was told in this article. I found that ESR in caps have a wide tolerance range and the only way I could stabilize was to pick a very low ESR cap and add a presistion series resistor of the right value to get the required phase margin and stabilize the supply. Works in any supply that has a feedback loop. In the instrument panel the switcher for the flourescent tube doesn't appear to have a feedback loop so instability may not be a problem but schematic is not very informative.
So was the engine running and then just died? Explain what happened.
My wife had driven the car, pulled it into the garage and shut it off. The next day it simply wouldn't fire up. I checked the fuel pump and it was good. Next checked the ignition and no spark on either side. No prior problems except I had gotten no engine check lights and I expected I needed to replace the O2 sensors as the car has 155,000 miles. Also the gas mileage has been much worse compared to my 1993 LS400. Performance otherwise has been good.
I replaced the timing belt (used premium kevlar belt), spark plugs, and water pump (since I was in there anyway) on both my LS400s back in 2009. Both have run great until this one just died. Belts look like new.
Some ECMs can be forced to issue a spark command to the ignitors by pulling up to +5 V (or down to ground in some systems) if the ECM is good but I have not done enough research to know which terminals on the ECM to try this. Has anyone done this?
05-20-17, 04:57 PM
