EGR delete 1980 ZX N/A

[Reptoid Overlords]

Upon removing intake manifold, EGR threads broke. Easiest option is EGR delete. No emissions, no O2 sensor. I understand how to plug it, and I don't expect any performance gains. My question is if there is any negative effect on the car, and if anyone has done it, what were the results.

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[siteunseen]

On my '77 there is an EGR tunnel on the bottom of the intake.  When I wanted to delete the EGR and all the accompanying components most every mechanic I asked about it told me the intake needs the heat from the EGR going through that tunnel to perform as designed.  Of course I did it anyway and have never had a problem BUT I live in the Deep South, it's 65 degrees outside right now.  One friend who raced his 280 told me the intake would "frost over" after the delete so he put small light bulbs over his when he raced farther up North to heat it up.  You'll need to delete the BPT valve and the warming plate with the thermal vacuum switch behind the thermostat housing.  Then plug the vacuum line under the TPS.  Yellow circles in these two pictures.

I found the cheapest way to acquire a block off plate was go to a local parts store and buy the EGR to intake gasket.  Get a peice of 1/4" aluminium and transfer the gaskets dimensions to the aluminium and cut and drill, smooth the edges with a bench grinder.  Then you have the gasket and a block off plate. 

[siteunseen]

Here's that warming plate.  I really can't remember if is part of the EGR or just extra crap I wanted to get rid of, sorry.  It seems like one of the vacuum lines coming off of it was tied into the EGR somehow?  Too many years and too many beers ago. 

EDIT: I found a good read.  

 

 

Edited January 22, 2017 by siteunseen

[Reptoid Overlords]

Okay, many thanks. I'm in the northwest, but the part that just rains and rarely gets below the 20's. I'll take the advice on the aluminum plate.

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[Zed Head]

3 hours ago, siteunseen said:

Here's that warming plate.  I really can't remember if is part of the EGR or just extra crap I wanted to get rid of...

 

I think that started design life as the heating block for the AAR, in the early 280Z's.  But it looks like Nissan added some function with that  vacuum switch.

[Reptoid Overlords]

Mine has the air sensor where the flat plate on yours is. I've left that. Right now the exhaust header EGR flange nut is soaking overnight in PB blaster. It'll be plugged and back together as I have time through the week. Turns out the EGR system had 2 leaks anyway.

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[Reptoid Overlords]

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[Reptoid Overlords]

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[Reptoid Overlords]

So I'm posting to this thread so as to not clutter/start a new one.  Again the car in topic is a 1980 non California U.S. model 280ZX Non-Turbo manual transmission.  Totally stock and from what I can tell, never taken apart aside from some minor external engine components(alternator, maybe starter etc..no Vacuum lines)

  I just completed replacing the intake/exhaust manifold gasket with a Victor Reinz gasket, along with all the vacuum lines.  Also, as the beginning of this thread states, I deleted the EGR components. 

First, the problem.  After everything was put back together, the car ran like a golden chariot.  But, there now exists an exhaust leak that most certainly wasn't there before the job. 

The reason for replacing the gasket was due to several leaks discovered on the intake side after spraying throttle body cleaner on the idling engine resulting in RPM fluctuation. It did not have an exhaust manifold leak at this point, as far as I could tell(it was quiet). 

So I'll focus on the gasket replacement steps, then the EGR delete.  Fast forwarding past the removal of the intake/exhaust manifolds(I was careful with them and broke no bolts), I cleaned and scraped the surfaces of the head and intake/exhaust manifolds to free up any old gasket material.  Did not have them milled/machined.  I applied some copper exhaust gasket sealant on the gasket/manifolds and head(all mating surfaces)  Cleaned all bolts and re-used them. 

 I hooked up the downpipe, using new bolts and new gasket.  Had assistant hold exhaust manifold to line up holes and finger tightened bolts(1 stud on #6) torqued to FSM spec.

Installed intake manifold by setting a few teeth in the head, and sliding into fit, tightening to spec.  It all went in pretty smooth, as far as I could tell.  It should be noted, that I took the exhaust manifold to a machine shop(trusted one, but everyone makes mistakes) to have the EGR hole on the BACK of the manifold welded shut.

The EAI pipe on the front of the exhaust manifold remains, as does the entire Air Induction System.  I plugged the intake manifold holes(bottom from EGR tube from exhaust manifold, and inner port to BPT valve) Removed BPT valve and plugged associated ports. 

I took Siteunseen's advice and fabricated a block off plate and used the new EGR gasket for additional seal where the EGR valve once sat. 

As for the heat plate that was mentioned earlier in this thread, I have checked the FSM and it appears to have vacuum functionality(type D-2 lists distributor spring, vacuum source) so I left it and the AAR on top if it. 

Of course, I could be totally wrong.  I plugged the vacuum line from the bottom of the TB, under the TPS.  There are 3 lines there.  The middle one(longest metal line) is the one I capped.  I followed its path to a port on the heat plate, and blocked it off as well.  The other lines remain.

  So, coolant flows from the thermostat housing, to the heat plate.  After everything was double checked and back together, I fired up the car and noticed excessive exhaust noise coming from the engine. 

Everything ran great, however.  I applied some TB cleaner spray where there were once intake leaks, everything is good.  To help locate exhaust leaks,  I decided to let it warm up and do a seafoam treatment after all the penetrating oil and nuclear waste dissipated from the engine from the job.

  After letting it heat soak for about 30min, I started it and after the initial blast of nastiness, I noticed a small, steady stream of smoke from the #1 exhaust port.

I let it cool down, and went back in and re-torqued all the exhaust manifold bolts.  Some were indeed looser than I felt they should have been(half a turn loose).

Another quick seafoaming produced no smoke from the exhaust manifold, or entire system other than the expected smoke from the tail. 

It should also be noted that there are several known holes near and on the muffler.  One forward of the muffler and several at the pipe from the muffler to the atmosphere.  This produces a confusing amount of smoke, even entering the engine compartment from beneath the car when there is as much as a breeze outside.

  But alas, the noise persists.  The reason for the thread is to see if anyone has any insight as to what I might have missed or buggared up.  I apologize to the reader who obtains a headache from reading this long and wordy post.  Of course, I might end up having to re-do the gasket job.  But any advice before doing any re work like that would be graciously appreciated.  Thanks for your time. 

[Zed Head]

Wow, that is almost a perfectly square, unbroken block of letters.  It fills up all of my computer screen.  Kind of neat to look at, but it also looks like about three meals on one plate.  Could take time to consume before you get some feedback.

Just an aside...

[Zed Head]

Couldn't get through it.  Could you state the issue you're working on so certain key words will pop out of the pile?  Not giving you a hard time.  It is seriously unreadable.  Or you could edit it in to paragraphs.

Think I found it - "  I fired up the car and noticed excessive exhaust noise coming from the engine. "  and " alas, the noise persists".

You need to add more detail about the noise.  

Edited January 30, 2017 by Zed Head

[Reptoid Overlords]

Yes. My apologies. I replaced the intake/ exhaust manifold gasket and deleted egr. Car runs great. But now there's an exhaust leak somewhere in the engine. Sounds like #1 exhaust port. Should I have deleted the line from the air cleaner box to the front of the exhaust manifold?

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