Last week I had a no start condition and a check engine light on. I pulled codes and found Code 1-3-1. I replaced the crankshaft position sensor, which I believe is referred to as an impulse sender in the wiring diagram. That seemed to clear up the issue and she ran great until this morning, when I initially got a no start then after several attempts she started but I had a check engine light and a code 1-3-1 again. I think it is doubtful that the sensor is bad already. The wiring diagram seems to indicate that the impulse sender feeds directly into the Ignition control unit. Which seems to indicate that I either have an issue with the wiring leading to the ignition control unit, or the unit itself has an issue. Has anyone else had this issue, could it be as simple as a bad coil, cap or rotor, maybe a hall effect sensor? Does the Ignition control get an rpm signal from more than one source?

Thanks in advance,
Don

If it rained recently, the ICU might have gotten wet.

"Has anyone else had this issue, could it be as simple as a bad coil, cap or rotor, maybe a hall effect sensor?"

Probably none of those items. Definitely not any of those items will cause a 131.

"Does the Ignition control get an rpm signal from more than one source?"

No, just the CPS you replaced. Other causes are pushed back terminals in the connector where you plugged it in, and I've experienced an out-of-box failure on a new CPS (Bougicord). But you got the 131 from the fuel side, right? Socket 2? The EZK reports this on socket 6 as a 214, but rarely keeps it.

Check for telltale water track out of the rim of the wiper motor grommet.


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Art Benstein near Baltimore

I'm reading a book about anti-gravity. I just can't put it down.

It has rained quite a bit recently but I thought the I CU was located under the dash on the passenger side. As far as I know I have no leaks in that area, but I will check.

Use a flashlight.



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Art Benstein near Baltimore

Did you hear about the cross-eyed teacher who lost her job because she couldn't control her pupils?

I doubt it is getting rained on, I pulled the panels and watched the area with a couple of bright lights while my lovely assistant the Mrs, sprayed water from a hose all over the area with the hood closed. And poured water directly on the area with the hood open. No seepage of any kind was noticed. All this was done with the battery disconnected. I did notice that one of the pins on the female side of the impulse sender connector was a little loose (maybe) and I tightened it with a pick, then applied dielectric grease to the connector and reassembled. Battery was reconnected and she started up just fine, no codes shown. Drove it all over town yesterday and she ran flawlessly.

OK, I've got my fingers crossed.

As for the grommet leak, I found traces of leakage on every outside-kept 240 I've seen since first emptying that drowned ICU and the not-Weathertech tray underneath. The path is from the cowl vent onto the shelf below from where it pours smack-dab onto the wiper grommet in the firewall.








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Art Benstein near Baltimore

All the toilets in New York's police stations have been stolen. The police have nothing to go on.

Thanks for that info on the o ring. If it happens again I will probably do that in any case. When we changed the CPS I clipped it to the firewall in an existing clip for other wires. It dawned on me today that that connection may have been getting wet due to its location, right under the wipers. Also even though we did try to make it leak it was only for a few minutes, and it can take time for a leak to show itself. Fingers crossed on this end too. Hoping most of the bugs are worked out for a while.

Art, If that is the issue whats the solution, RTV? around the exterior rubber housing?

Thanks I'll check that. It starts fine now but still has the check engine light.