Failed Emissions

Nero

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Lol, in later years the ENGINE light was swapped out for a CHECK ENGINE light, but I think that was an OBS thing. In laws IDI has a CHECK ENGINE light, and it's a 1993.
 

ISPKI

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You have a cel, as I do on my 94,93,92,91, 89, and 87. If you want it to illuminate, or check the bulb/cluster for function, disconnect the factory oil pressure sender wire and start the truck. All of mine have a cel and they function. Driver side center just in front of bell housing for na idi. Turbo models I belive(could be wrong) are atop the turbo next to the oil feed line. X4 on different shop
Are you positive about that? I have disconnected the oil pressure sender on multple IDI trucks and never seen a CEL. Also, no cluster I have ever seen on these has had a CEL. Maybe its something different but My trucks do not have a traditional CEL.

Also - There is no computer and no way for them to plug into it and run diagnostics. Diesel trucks of this age are supposed to be tested for opacity at the exhaust pipe tip only.
 

frankenwrench

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Every single one of mine has an engine light. And none have ecm/ecu/pcm. All manual transmission. Only way I can make it come on is disconnecting the oil pressure wire or actually running outta oil
 

Zephyr

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I may not be a great mechanic but I know running out of oil is bad, LOL.

I tried your recommendation of unplugging the oil pressure sender. Still no CEL or power to the light socket. I assume something faulty in the in-dash gauge connection with the idiot light (check engine light). At this point I don't really care, the mechanical oil pressure gauge reads and works fine.

Now having wasted the day yesterday with this, I have to dispute the reported "failed" emission test. Colorado emission stations report to the state so I may not just be able to go to another shop without some sort of waiver. Diesel owners in this state can be liable for $750 worth of repairs to get a waiver. I have to see where this red tape fiasco leads. Ya'll can be thankful you live elsewhere! Too many stoners making the laws here.
 

Cubey

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Check the wiring schematic first but grounding out the oil pressure sensor wire might make the engine light come on. Had the wire dangling loose on a 1978 Dodge, bouncing on the transmission bell housing, making the engine light flicker as it made and broke contact. That's how those oil pressure sensors usually work. Lack of proper pressure grounds out the wire, making the warning come on, good pressure breaks the contact, turning off the light. So, just unplugging the wire makes it think it has good oil pressure since no ground.
 

Zephyr

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Thanks everyone for the assistance! I called the emission station/shop that saw it yesterday. After explaining to them the lack of on-board computer and of any useful function of this idiot light, they decided to contact the state emission people who agreed that a tail pipe emission was adequate and will be passing the truck. 2 trips to town and a shot afternoon researching and pulling my dash apart, but we should be good for another year.

Oh well, it was another learning experience and test of my patience. Have a good week, ya'll.
 

Noiseydiesel

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Date of manufacture on the door is what?
Your motor vehicle dept should be abler to give you an exemption on your antique.
My local DMV gave me one on my '87 6.9 toy. The '02/94 7.3idiT is under the same umbrella.
 

Cubey

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Date of manufacture on the door is what?
Your motor vehicle dept should be abler to give you an exemption on your antique.
My local DMV gave me one on my '87 6.9 toy. The '02/94 7.3idiT is under the same umbrella.

I don't know if other states are doing the same, but in recent years, Arkansas changed the vehicle age from 25 years to 45 years to qualify, because the state govt politicians didn't like people registering 1990s vehicles as antiques.
 

Zephyr

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Date of manufacture is 11/93.

Colorado collector's vehicles must be 32 years old or 1975 or older according to the website. Apparently politicians can't do simple math because 2022 minus 1975 is 47. Either way, it's not quite there.

It was good to see my 28 year old truck pass emissions with 1/3 of allowable levels... Maybe not as fun as shooting pheasants with my grandfather's 105 year old Model 12, though.
 

Cant Write

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@Zephyr, I am on the western slope, hopefully that CARB stuff doesn't make it here anytime soon. None the less glad you got it figured out. Also I would recommend WY or SD over NE for tax reasons, but that is just speculation through conversations with friends.

To everyone else, can't you just short 2 pins (A & B I Think) on your OBD1 connector and have the CEL illuminate even if there are no stored codes (No ECM)....?

I do it on my TBI V2500 Burb (gasser) just did not know if it works for all OBD1 stuff across the manufacturers.
 
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