Rapid flashing CEL (1 Viewer)

[Fiddynut]

I've got a 94 80 series. Truck had been running fine. I haven't driven or started it in about two weeks. It has a CEL light for EGR temp sensor for a long time now with no issues. I started the truck and it didn't do its normal cold start high rev, it went strait to about 6-700 RPM. Has hesitation when throttle is applied. So I shut it off and crossed up the pins to see the CEL and it's just rapid flashing. I know what that means on an OBD2 car and assume the same meaning in my 94 but what's the best way to diagnose it? Is it most likely a miss fire? Plug wells are dry, My multimeter is being a POS but I'm getting "k" ohms when I test the plug wires. I've gone ahead and ordered cap, wires, and plugs from Joey but is there anything else I could check? Thanks in advance.

 

[JunkCrzr89]

94 is OBD1 so Count the number of flashes to get the code. In other words, 2 flashes followed by 4 flashes = code 24. If there are no codes, it will just flash continuously without any pauses.

 

[Fiddynut]

94 is OBD1 so Count the number of flashes to get the code. In other words, 2 flashes followed by 4 flashes = code 24. If there are no codes, it will just flash continuously without any pauses.

When it got to 100 I stopped counting. I know how to read the codes. It's just flashing, fast.

 

[JunkCrzr89]

When it got to 100 I stopped counting. I know how to read the codes. It's just flashing, fast.

If there are no codes, it will just flash continuously without any pauses.

So your problem is mechanical, not sensor/electrical sourced.

 

[Fiddynut]

So your problem is mechanical, not sensor/electrical sourced.

Lol damn, for some reason that part didnt compute. Thank you.

 

[FMC80]

Did you recently do any maintenance? Did you disconnect the battery for any length of time? If so, after reconnecting the battery the revs will be lower until your ECM learns or some s***. At least that’s what happens on mine after a battery disco/reco, and I read on here that it’s normal in that situation.

 

[Fiddynut]

Did you recently do any maintenance? Did you disconnect the battery for any length of time? If so, after reconnecting the battery the revs will be lower until your ECM learns or some s***. At least that’s what happens on mine after a battery disco/reco, and I read on here that it’s normal in that situation.

I did. I'll let it run up to full temp today. Thanks all!

 

[FMC80]

I did. I'll let it run up to full temp today. Thanks all!

It will take a few on/off cycles to get back to normal. I think I read it was 5 but I can’t be sure.

 

[Spdstr280Z]

I guess the battery disconnect also explains how it could have no codes even though you mentioned you had a CEL for EGR termp. Does your 94 actually have an EGR temp sensor, or the factory resistor plug like 93's ?

Jason

 

[dpeshkin]

It will take a few on/off cycles to get back to normal. I think I read it was 5 but I can’t be sure.

Is that why my LC always runs so poorly (low rough idle) after the battery is disconnected?

 

[Mrtwooooo]

My 80 did this recently on a trip out west. After the second day or 12 hour drives I noticed when I turned the key to the On position without cranking it I had a very rapid flashing CEL. Starting it caused the CEL to go off and it always ran perfectly. My only guess was I had never driven the cruiser that much in a short amount of time, I had also changed quite a bit of elevation as well. The next day it stopped flashing. My best guess from searching online during the trip was it was some Readiness thing that the ECU goes through for I think emissions, and after a few cranking cycles it typically goes away.. which it did.

As far as battery being disconnected and a low rough idle. I think that all had to do with the ECU forgetting parameters because it lost power and it has to figure out how to idle again.

 

[FMC80]

Is that why my LC always runs so poorly (low rough idle) after the battery is disconnected?

Yes. When it first happened to me, much to my kids dismay, I ended up cancelling a beach trip for fear that my cruiser would break down. Subsequent research led me to find out that this is perfectly normal operation.