thesheriff

I am coming up do on a smog and the check engine light is on. I know the code is regarding the EGR. Does anyone have a photo or diagram of the EGR set-up. The crossover tube is clear and free of debris. I am open to any thoughts or suggestions. Thank you very much the help.

gorms

There really isn't much to it, pretty crude design. Check the diaphram with a hand vac to see that it opens properly under vacuum. Not sure of the # in. of vacuum it should open at, but you should see the valve open at around 15-17 inches guessing, should not leak vacuum either. Beyond that make sure the vacuum line leading to the solenoid (between oil fill and #1 valve cover IIRC) and all other vacuum lines are intact and don't leak.
The IAT sensor sees a higher temp at the intake when the valve is supposed to open, or else the light comes on. There's a diagram around here somewhere on how to fool it with a relay and a 1.2k ohm (don't quote me on that number) resistor.

BigIron70

Also check for cracked or broken vac lines. Usually if your cruise control quit working then the plastic vac line for cruise control has most likely broken. Usually breaks right next to the servo under the battery. A real pain to get to the servo vac connection. I had to take the headlight asy. out to repair one today. Check to make sure no other vac lines that run across the firewall under the cowl seal are broken or split. Had a truck just today with this same problem, EGR failure that came into the shop. I ran a vac hose instead of the plastic tube used. With vac leak there was not enough available vac to operate the EGR valve, so it set the code for EGR failure

thesheriff

Thank you very much for the help! I will dig into it this weekend and let you know what I come up with.

dieseldemon

If its a 12v there is no smog check in Calif the truck was manufactured in 1997.

thesheriff

In 98 there were two motors the 12 valve (1998) and the 24 valve (1998.5). Unfortunately, even though a 12 valve, I still have to get it smogged. The motor is a 1997 which would have made things really nice if the truck shared that year. This is the second smog I have had to do.

infidel

Maybe this will help> http://www.cumminsforum.com/forum/94...-deletion.html

dieseldemon

Go on the DMV website and down load the Regs take them to the DMV and they will exempt your truck if it is a 1998 12v engine it was Manufactured in 1997

thesheriff

I went to the DMV website and this is what I found:

Policy
Effective January 1, 2010, smog emission inspections are required for diesel-powered vehicles 1998 year-model and newer, with a gross vehicle weight rating (GVWR) of 14,000 pounds or less, for original and transfer applications. This includes vehicles manufactured in 1997 that have a 1998 year-model designation. Biennial smog inspections are required for these diesel-powered vehicles for renewal applications with a registration renewal date of April 30, 2010, or later.

Where did you find the info about the 1997 manufacture date exception? I am definitely interested in finding that. I would love to get out of having to smog this thing. Thanks again for the help and info.

Danavilla

That link includes a sketch I developed to show how I resolved the CEL problem after blocking off the EGR on my '98. It wasn't intended to get around smog regulations since it is a modification of smog equipment.

At issue is CA DMV's determination that all 98s would require smog testing. I too interpreted the law to exclude 12 valves but apparently DMV doesn't agree.
Has anyone heard of a successful challenge?

dieseldemon

I have several custs that have the 98 12v and got past the smog the Dmv site was changed to read 97 Manufactured and I just looked and you are right it has been changed back to 97 and older year model I will check with some of my cust and see if they are still not having to smog their trucks