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HELP! Need correct info on 89 Jimmy 350 EGR Valve.

Mav2u

Mav2u

1/2 ton status
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I need to find out the correct part number and what is the correct type of EGR valve to replace. The book shows a Port, Negative, and Positive types were available for this truck. Port for vehicles 5.7/7.4 ci with a GVWR over 8500 and negative for vehicles below 8500 GVWR.

Well I have a positive flow one on the truck now, which according to my Helms manual is the incorrect one. Apparently the people who replaced it before did something incorrect.

You say, "How do you know it's not a negative back pressure EGR" because it doesn't do the vacuum gage test.

I need to change this to correct this error, assuming it is incorrect because the truck is running a little off, like a bad EGR valve.

Please help, if anyone has access to All Data info or oem info please check it so I can figure this out.

Or check your 89 5.7 350 truck and let me know what you have on it.

Thanks everyone,
Jeremy
 
Re: HELP! Need correct info on 91 Jimmy 350 EGR Valve.

Pull the vacuum line running the valve. If the problem goes away, the EGR valve is the problem. It should be that simple...with no vacuum, theoretically the valve can't open. (have heard that exhaust pressure CAN open some of them, sometimes though)

If your EGR valve opens at the wrong time (say, idle) your engine will die, plain and simple, as no port on a carbed or injected vehicle, that I am aware of, is capable of "limiting" vacuum, that is why you have an EGR solenoid.
 
Re: HELP! Need correct info on 91 Jimmy 350 EGR Valve.

I understand how it works, I wanna know what the correct EGR Valve type is supposed to be. I know what the books say, Helms manuals. The parts store lists two EGR valves, which they ask you for what the OEM number was. I don't have the OEM one, the people who had it before me apparently changed it. I just need to know if it is the wrong one by confirming it with what the OEM factory numbers.

So what I need to know is:
What does a 89' Jimmy 4x4 350 with a GVWR of 5000 need for a EGR valve.
What does anyone else with the same style 89 K5/Jimmy have on their truck right now.

I'm not concerned with troubleshooting the system. I can do that, I need to know what the correct part should be or if it varied from the factory.
 
Re: HELP! Need correct info on 91 Jimmy 350 EGR Valve.

[ QUOTE ]
I need to change this to correct this error, assuming it is incorrect because the truck is running a little off, like a bad EGR valve.

[/ QUOTE ]

You said you are assuming it is incorrect. If you test it, that should tell you, without having to find the OEM EGR valve number, no? If the valve isn't the problem, who cares if it's "wrong"? Plenty of people run the "wrong" carbs on their trucks, doesn't mean it won't work correctly.

Seems a lot easier than finding the OEM number, of which I bet there are at least 10 for vehicles the same year/setup as yours.

If I need to make my intentions more obvious, in a negative vs. positive backpressure system, if both see vacuum at the same time, does it not stand to reason that one will be open, and one will be closed? If so, I really doubt your engine will have a "little" problem with running. Again, with the valve disconnected from a vacuum source, troubleshooting should be easy.

If you want to throw away whatever an EGR valve costs, go right ahead, plenty of people have replaced parts with no results in the past. Maybe you'll be the one in one thousand who gets it right with the first guess.
 
Re: HELP! Need correct info on 91 Jimmy 350 EGR Valve.

I have a 91 3/4 ton Burb (8600 GVW) w/ a 350. I think we're in different weight classes, but if it helps, I can check if there is a legible OEM # on the EGR valve.

Eric M.
 
Re: HELP! Need correct info on 91 Jimmy 350 EGR Valve.

Yes, please gimme what number you have on your burb for an EGR.

Yes it does matter what part is on the truck, hence the different parts for different weight classes which use a different EGR solenoid contoller. No this is not the only issue I have but I want to know.

So unless you know what the correct part is, or have a TBI controlled K5/Jimmy (burb also) then please don't comment. I know a truck can run without it, I know a truck can run half arse with a disfunctional one, I know how to troubleshoot to see if one is bad on a negative pressure EGR valve. Positive pressure valves you can't test. ( at least not that I ever seen or read about )

I want to know because that is something I would like to get straightened out. Because if I'm right then the part store is wrong and they are selling everyone the wrong parts. I don't like buying the wrong parts and I'm sure nobody else does. So if I can find out, correct it, then everyone has the right part that they paid the big money for. Oh, and the world will be a happier place I'm sure. /forums/images/graemlins/grin.gif

So please no more about testing the EGR valve or solenoid as I don't care about that detail at this juncture. Just what was on these buggers as OEM part numbers, what replacement you have on there now if you don't have a OEM one still on yours.

/forums/images/graemlins/grin.gif
 
Re: HELP! Need correct info on 91 Jimmy 350 EGR Valve.

Sorry on the 91 Burb, but no # on the EGR. It must be a replacement and who ever did it didn't put the sticker with the new number on.

Eric M.
 
Re: HELP! Need correct info on 91 Jimmy 350 EGR Valve.

See, now isn't that dumb?! Damn part should have a number on it. They wrote the number on mine but who's to say that they weren't dumb as a box of rocks.

So, anyone else with a 89 to 91 blazer or burb with a EGR number?
 
Re: HELP! Need correct info on 91 Jimmy 350 EGR Valve.

I just bought an 89 Chevy K5 w/ a 5.7. I forgot to get all the records from the previous owner, so until they arrive in the mail I won't know if the EGR vavle has been changed before. But, I'll take a look for the number while I'm at the station tomorrow, for what it's worth to ya. Tha is, if there is a number to find on it.
 
Re: HELP! Need correct info on 91 Jimmy 350 EGR Valve.

Sounds good. Seems like anything other than OEM they leave a white label for you to write on in the middle of the EGR what the old number was. Not very reliable if you ask me. I'm sure the EGR valve fits a great many vehicles but damn, least they could do is put some sort of reference number on the part.
 
I've got a '91 Blazer and I just replaced the EGR about 6 months ago. The oem # on the EGR I took off is #17087194. Hope this helps. /forums/images/graemlins/rotfl.gif
 
Re: HELP! Need correct info on 91 Jimmy 350 EGR Valve.

Well, I looked over, and over, and I can't see any number on it anywhere. If there is one on it, it would probably have to be removed to find it. /forums/images/graemlins/dunno.gif Good luck with the hunt.
 
Hmm, I crossed the number with the the parts store again and it came up as a positive backpressure EGR Vavlve again. The book calls for a negative back pressure for all trucks with a 5.0/5.7 liter v8 under 8500 GVWR. Is that what your truck fits under?
 
Mine is under 8500 GVWR. I am positive about the # on the EGR valve, but I am unsure that the P.O. didn't replace the EGR with the wrong application. I have always had a hesitastion/stumble problem with this truck. Plus, the EGR passage was completely sealed with carbon deposits when I replaced the EGR. I had to chip the stuff out. So, I am not positively sure that I have the right EGR on the truck.
 
It basically boils down to the fact that they offer two options for an 89 - 91 5.7 Blazer/Jimmy. One is a small EGR that is Negative Backpressure and one that is large 3" diameter approx. Positive backpressure.

I have my helms books and it shows my EGR valve control solenoid mated to the negative backpressure EGR valve and the testing procedures are for a negative backpressure EGR for vehicles under 8500 GVWR. So what is the dealio? I don't know, I wish I had an original OEM EGR valve to see if it is a negative backpressure valve or not by hooking it up to my vacuum gauge.

Positive backpressure gauges you can't test with a vacuum gauge, hell, I don't know how the hell you tell if they are going tits up or not on those things.

Maybe someone has a picture of a OEM EGR from 89-91 with a GVWR under 8500 and a picture of their EGR control Solenoid. I'd post the pics on my site if anyone needs help in posting them.

I have a gut feeling the parts store is wrong on this one and alot of people have the incorrect EGR valve on their rig. But who knows until we get some more information in from other 89-91 owners.

Mav
 
Well, I can take a pic of mine when I'm at home. I have a crappy digi cam, so I don't know how clear it will come out. Maybe at least, it will be of some help.
 
Anything is better than nothing. I'll to get a snap off of mine also and my EGR solenoid controller. Maybe a scan off of my Helms book showing the devices so others can compare to what the book is saying.

Mav
 
I just replaced mine yesterday on my '90 K5. The OEM part number is: #17087194

The new one and old one look almost identical. Here is a pic of the new one:

2-3054D.jpg


Hope this helps.
 
Well, once I got some better light in there to take the pic, I was actually able to see the number. I can still post the pic if you need it, but it didn't come out very good.. too much light.

Heres the number:

DCR 17087194(1) >> (can't tell for sure, but it looks like a 1, may be just a mark.
188 91N

DCR should be the plant, 170871941 should be the part number, 18891 should be the build date, & the N is for the negative back pressure.
 
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