Recent content by RDub

I think just run it. What shop did the work, mine was done by A-1 on Federal? Other than the paint he did a great job.

I was super bummed about mine after I got it back. Not only was it a crappy spray job it hadn’t been cleaned well before paint and some of it never dried. Got all over me during installation a week later. I feel your pain.

Unless the paint is ridiculously thick it won’t affect the heat transfer enough for you to measure on your truck. As said, if it’s so thick it reduces airflow you probably should remove it. From your picture it looks nice and thin. My original unit came back that way from repair, too, and I saw...

That makes sense at WOT.

Thanks! I think the EGR valve can definitely cause stumbling at cruise. The EGR VSV opens when the engine rpm is above about 1500 (mine opens at around 1300) regardless of whether there is high enough exhaust pressure to force the vacuum modulator to open the EGR valve. The emissions manual has...

My NOx fail might be due to the profile the emissions test follows. It’s a speed vs time curve, simulating driving on a road with various inclines and flats. There aren’t really any hold periods aside from when the slope of the curve relaxes a bit. I have the graphs of HC, CO and NOx...

Forgot to mention that for some reason the emissions techs here no longer open the hood or check for a Cat. Colorado has adopted the CARB regs for replacement Cats and I did buy one. It seems to be working, the HC and CO numbers are spectacular now.

Thanks. Agree with all except the Ford part. That part is intended to dampen the action of the EGR valve since mine is “too active” in its current state. But it didn’t work for the test, for whatever reason. If I run the engine with EGR setup per the factory it literally can’t be driven. It bogs...

I live at about 5500’ elevation so the HAC is always on high altitude mode, confirmed by emissions manual tests. I’ve read that retarding the timing can help reduce NOx. Does anyone know if disconnecting the HAC at the distributor will retard timing enough to make it worthwhile for a retest?

Ugh. That’s Ugh. Mine failed emissions again today. New Cat so HC and CO were fine, but NOx was about 15% above the limit. I had the EGR connected with the Ford VTV correctly oriented in the line to the valve. Still stumbles at cruise, so I assume the valve is shot. Can a valve that opens too...

Finally got good enough weather to try the new vacuum modulator and the Ford VTV. Tried just the Ford part with the original modulator first, and that pretty much took care of the stumbling everywhere. Then I tried just swapping in the new 80-series modulator without the Ford valve and that was...

From @DFXR:

I’d prefer to use a Toyota part but for this round I’m leveraging the work @DFXR has done with the Ford part. Is there a way to compare the specs between the Ford and Toyota VTVs? I haven’t seen a way yet, but others probably have done more research.

I’ll be glad to test each separately and report back. The Ford part number comes from @DFXR in another EGR stumble thread he referenced earlier in this thread. This is from his post: There are several for sale on eBay, most are NOS.

Thanks! That gives me more confidence. Both the 80 modulator and the VTV are arriving at the same time so I will experiment both ways. I bought the 80 part from Partsouq for $65, along with a bunch of other small items to make the $27 shipping charge worthwhile. I’m in Colorado in an emissions...