[Marks6.OH]

Ok the title seems odd, but here goes. My truck has 140,000 miles and since I got it, I installed a boost and pyro guages. (at around 45,000 miles) When towing I have seen boost consistently around 28-30 psi pulling steep passes. After doing an EGR delete/cat gut, I noticed a significant decrease, 23-25 psi. I spoke with a ford tech who said that the "computer" not seeing the EGR valve would likely not boost as much. (waste gate kinda thing) No check engine light ever comes on. I went back to the shop that did my delete, and we put a used/working egr valve in place of the block off plate and plugged it in. Boost was restored. We pulled the valve, (I thru mine away) and re-installed the plate, and cleared codes concerning EGR. Boost stayed normal until a couple of years later, after changing batteries and alternator(truck with no electrical power) I have the same problem. I also think that the FICM has been degrading due to truck age and battery/alternator failure, cold start issues. My question (finally) is will a new FICM/repair (ATLAS 40?) restore boost without installing a dummy egr valve? I think that the codes, if any are again retarding boost. I don't have a reader, truck is not chipped, does have a nice free flowing exhaust tho.

Thoughts?

I have been trying to get in touch with Ed at FICMrepair.com with no luck yet and pick his brain.

 

[TKOPerformance]

Run an EGR valve. The EGR valve signal not only effects the turbo, but also the cooling fan operation. Having it in place with no cooler there's nothing it can do if it were bad, but the reference signal it sends to the PCM is important.

The FICM does have something to do with turbo response, etc. So that is a possibility, but the truck is never really going to run right without the reference signal from the EGR valve.

 

[Marks6.OH]

So I have a used EGR valve that had a problem, not sure what it was, will it work or do I need a new one, or a "used but good" one?

thanks
Mark

 

[TKOPerformance]

It doesn't have to work. So long as the solenoid is good its fine. I believe what happens is that the PCM reads the resistance value through the solenoid. If the solenoid has an open winding it probably wouldn't work, but otherwise it should be fine. If its just stuck, like most EGR valves I've seen fail, its fine.

 

[Marks6.OH]

Ok, so I installed my "used but good/questionable" EGR valve, and took it for a test run, no 5th wheel, but I did see 22 psi when a full throttle run was done. Then, went to O'reillys auto, and they pulled the following codes and then cleared them for me.

P0528 Fan Speed sensor, P0403 and P0405, EGR valve stuff. Hopefully the PCM sees that all is well, and starts allowing full boost. I will check codes in a couple of days and hopefully all is good. Otherwise I need a new EGR valve I suppose.

Thanks for the info TKOPerfomance!

Mark