Olds 88 403ci ok to leave EGR disconnected?

Hi, my buddy's 1977 (I think, it might be a '78) Olds 88 w/ the 403 ci surges badly when the EGR is connected, so he disconnected his EGR to normalize it. Any idea what may cause this? The vacuum sticker shows some kind of "doohicky" in the vacuum line, but his seems to be missing, what is it and where can he get one? Or do you think the EGR is unnecessary to have hooked up? His car is in excellent condition otherwise. There are no emissions testing here. Any advice welcomed.

Hello. The "doohickey" you mentioned might be a one way check valve.That EGR valve might have a bad diaphram in it,So when it is connected,It would have a vacume leak,Witch would make engine surge.You could (a) replace the EGR valve,and inline vacum check valve,OR (b) Leave it disconnected,(remember to plug vacume line off for EGR valve),Or (c) Eliminate it all together.You would to have to fabercate a steel plate and make a gasket for it to plug up the hole in the intake.Also,I would buy about 6ft of vacume hose,And replace every hose on that engine,As other hoses may be cracked ,Or broken.Does that distrubtor have a vacume advance on it?? I would check that too,Make sure that is working.I have owned many Oldsmobiles from that era 74s thru early 80s.And worked on everything on them engins.They are easy to work on,And I miss working in them.Any questions,You can contact me at [email protected] a good day!! Diesel 1962...

...Also,I would buy about 6ft of vacume hose,And replace every hose on that engine,As other hoses may be cracked ,Or broken.Does that distrubtor have a vacume advance on it?? I would check that too,Make sure that is working...
Hey thanks for the info. As far as I know he's rather particular with this car, so from what I can tell from looking under the hood, all the rubber is new or nearly so, lol. This car is garaged all the time and babied. Yes the distributor has vacuum advance, I don't know if he's checked it out though. I can ask him. Thanks again.

Hello,Glad to be of help.Now that I know that engine has a vacume distrubitor,When your buddy plugged in the EGR valve,The diaphram inside the valve is bad.Witch caused a big vacum leak,Witch caused the distrubitor vacume advance to malfuncition.That is why that engine would "surge".It could not keep the engine in time with a vacume leak.Anyway,Keep the EGR valve unplugged for now,Untill your friend decides what to do about it. Contact me if any more questions.Have a good evening! Diesel1962

Hello,Glad to be of help.Now that I know that engine has a vacume distrubitor,When your buddy plugged in the EGR valve,The diaphram inside the valve is bad.Witch caused a big vacum leak,Witch caused the distrubitor vacume advance to malfuncition.That is why that engine would "surge".It could not keep the engine in time with a vacume leak.Anyway,Keep the EGR valve unplugged for now,Untill your friend decides what to do about it. Contact me if any more questions.Have a good evening! Diesel1962
Thanks again Diesel1962, well I talked to him some more, he did replace the EGR valve assembly, but no change, so he's left it unplugged for now. Hmmm.......

Good Morning.I did further research,And I think that GM EGR valves were hooked up to a thermal vacume switch,Example,EGR valve would not get a vacume pull,Unless the engine was at a certan temperture.Also remember the "Doohicky" that the underhood decal said should be there,And you mentioned that it was missing? That very well may be a restrictor,Example,EGR valve is getting too much vacume,And is open all the time.Let me dig into some old shop manuales that I have .Perhaps I can see if I can find a vacume diagram for that year of car. Have a good day!! Diesel 1962

Thanks for the info.

Olds made a plate to fit over the EGR port to block it off for certain engine applications that didn't get an EGR valve, i.e. Marine, Export. You could make one by tracing the outline of the base of the EGR valve onto some 1/8" steel. If you are careful you may be able to reuse the gasket, and be sure to put some blue loctite on the bolts, you can reuse them too. Also remember to plug the vacuum port feeding the EGR valve after you eliminate it.