Worth fixing EGR

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Nov 28, 2008 | 05:25 PM

91Bronc300

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Worth fixing EGR

I'm wondering if it would be worth fixing the EGR on my 1991 EFI. I am certain it's the EGR vacuum solenoid that's bad, letting no vacuum reach the EGR valve, thus never operating. The truck doesn't get any better than 11 MPG. The truck has had the equivalent of a tuneup recent months ago. New wires, plugs, complete distributor, regular use of Lucasoil injector cleaner. I know a faulty EGR system is part of the mileage problem, I'm just wondering, how much of the problem is it? I am going to do a complete rebuild on the engine with a propane conversion next summer. I already have all the Impco parts. But I would like to get a little better than 11 MPG for the six months in the meantime if cheaply possible. And if fixing the EGR system only gives me another half MPG I'll just leave it alone, but if it could send me up to around 14 or so I will. Is it likely to be worth the money and effort? Thanks.

Nov 28, 2008 | 08:05 PM

herothc2003

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From: Southeastern N.C.

What is the purpose of the EGR anyway? I think mine also is not working.

Nov 29, 2008 | 03:54 AM

91Bronc300

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I don't actually know what the purpose of putting some exhaust gas back through the engine is supposed to do. I think it is an emissions regulation

Nov 29, 2008 | 04:00 AM

fmc400

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From: Austin, TX

It recirculates exhaust gas back into the combustion, which lowers NOx emissions and cools the combustion chamber. I think it will help the mileage problem, but you should really be seeing 20 out of that motor and I'd doubt that fixing the EGR is going to get you all the way there from 11. But it will help some, so I'd try it and see how much it helps. EGR isn't a big deal to fix.

Nov 29, 2008 | 06:01 AM

srercrcr

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At idle the valve will be shut so the engine will run smooth, but when the rpms go up, the valve opens some to let the exhaust gases in.

Nov 29, 2008 | 07:16 AM

spurredon

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From: Upstate NY

I had trouble with mine leaking . I took the three srews off the end that hold it together and put some vaccum grease (Dow 7), where it clamps together. It fixed my CEL problem and I think the truck runs a little better!

Nov 29, 2008 | 06:02 PM

91Bronc300

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I think you are probably right. Just getting to and from work for the next six months is 2800 miles. If a 35 buck part gets me another 2MPG or so it ought to be worth it. I love these engines. I had a 240 in an old F-100 and a 235 in an even older chevy apache and I think they are better engines than anything else I"ve ever owned. This 300 is kind of in sorry shape right now though. Audible bearing knock when you floor it, bad mileage. But it still doesn't burn oil. Great engine. I trust it to last until the summer when I'll tear it down. Can't wait to get a fresh rebuild on it and use it likes it's meant to be used