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RX-7 2nd Gen Specific (1986-92) RX-7 1986-92 Discussion including performance modifications and technical support sections.

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Old 11-21-2008, 04:59 PM   #1
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Default Removed EGR now have problems

Okay, so I went ahead and pulled the Upper intake manifold off to repair a fuel line that had decided to rupture. While I had it off I went ahead and removed the EGR and put the block off plate on. I went to start it up and it won't stay on. The NB reads 0 volts, which I think is lean, even while cranking and idling. Temperature and everything else seems normal. The plugs were a little fouled but nothing beyond normal. I haven't changed anything on the car besides those fuel lines. There were no electrical problems before. The only difference between now and the last time it ran is the temperature. (upper 40's to low 30's now)

What I'd like to know is if my removing the EGR if the low temperature would keep it from keeping a proper idle? It was running spectacular for about 30 seconds while I drove it around, then after that I pulled up to a stop sign and it stalled out on me.

Any suggestions?







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Old 11-21-2008, 05:18 PM   #2
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No vacuum leaks? Did you reuse the old gaskets? I always add a thin layer of red RTV when I reassemble my manifolds. I had too many vacuum leaks not using it!
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Old 11-21-2008, 05:19 PM   #3
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No vacuum leaks? Did you reuse the old gaskets? I always add a thin layer of red RTV when I reassemble my manifolds. I had too many vacuum leaks not using it!
I used red RTV on the block off plate. Didn't get to reuse the gasket (it broke on me when I tried to remove it). I'll check on the vac leaks and see if I can find any using propane.

Just checked for vac leaks via propane method, but didn't find any. Also for clarification the O2 reads around 0 volts. I forget which that is (it's either Rich or Lean) after thinking about it, it's reading Lean, not rich.

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Old 11-21-2008, 06:02 PM   #4
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sounds like a leak either at the EGR valve or the intake manifold somewhere..

You have ALL your sensors plugged back in right (including the AFM)
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Old 11-21-2008, 06:23 PM   #5
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sounds like a leak either at the EGR valve or the intake manifold somewhere..

You have ALL your sensors plugged back in right (including the AFM)
Yes. No leak was found. I retuned the Rtek to lean out the fuel to 25% correction. Seems to have fixed the improper idle. Went for a test drive and it pulls hard, reads correctly and is all round feels good. I need to adjust the fuel curve more, but it isn't that bad right now. Guess that means I know the EGR works.
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Old 11-21-2008, 06:29 PM   #6
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s4?
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Old 11-21-2008, 07:02 PM   #7
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s5 N/A engines have no EGR (I am unsure about turbo as the only s5 turbo engine I have is nowhere near stock).

I find it hard to believe that the EGR is making a 25% fuel difference (maybe at idle).

Do you know your injector size and duration?
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Old 11-21-2008, 07:05 PM   #8
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Injectors are still stock. 460cc/min and have a pulsewidth at idle of about 4.00ms or so (give or take a few here and there). This is an S4 N/A.

This is only at idle where i've tuned. Everything else is at the stock fuel curve. (aka 0% correction)
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Old 11-21-2008, 07:57 PM   #9
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What accessories are you running? My Haltech driving 460 cc primaries used 2.03 ms duration to idle at -75 kPa MAP I had only the alternator and the air pump for the auxilliary ports (no PS, no A/C). This idle seems a bit rich to me, but you also have the stock timing map (horrible for power or mileage).
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Old 11-21-2008, 09:27 PM   #10
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Fuel lines put on backwards?


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Old 11-22-2008, 12:51 AM   #11
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What accessories are you running? My Haltech driving 460 cc primaries used 2.03 ms duration to idle at -75 kPa MAP I had only the alternator and the air pump for the auxilliary ports (no PS, no A/C). This idle seems a bit rich to me, but you also have the stock timing map (horrible for power or mileage).
I'm not sure it's a problem with what I did anymore. I've since reset the fuel map to run at 0% correction. The problem itself seems to be intermittent in that it may occur during start up, it may not. It may occur while driving it may not. There appears to be no rhyme or reason to this. I haven't messed with any sensors or connectors besides the ones that connect to the UIM. Until I iron out this problem I'm not trusting the NB read out.
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Fuel lines put on backwards?


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I don't see how. I only replaced the fuel lines going to the secondary rail and FPR. Kind of hard to swap those.

I've double checked for vacuum leaks both visually and with propane, still no sign of one. Even on the the block off plate on the EGR.

These symptoms tend to make me think it's electrical in nature. Speaking of which my tach no longer sits at zero when off. It is sitting at 500rpm, which it never did before. The RTek reads out the correct RPM when on and off, and the RPM on the Tach matches the Rtek when running, just not when the car is turned off.

In response to what I'm running, I'm running the stock alternator, EFan, no radio or lights.
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Old 11-24-2008, 05:12 PM   #12
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No lights??? how do you see at night

Sounds like a ground, just not sure which one..... maybe try adding an extra ground to the UIM just to see... the tach thing leads me to believe its electrical as well... does it got to 0 if you disconnect the battery and hit the brake pedal?
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Old 11-26-2008, 11:43 AM   #13
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No lights??? how do you see at night

Sounds like a ground, just not sure which one..... maybe try adding an extra ground to the UIM just to see... the tach thing leads me to believe its electrical as well... does it got to 0 if you disconnect the battery and hit the brake pedal?
I don't know about that. haven't tried. will try in a sec. I've fixed the lean condition, but my tach still sits at 500 when off. Will try suggestion.
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Old 11-26-2008, 12:25 PM   #14
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I tried the suggestion of holding the brake while the battery is disconnected. No go. The Tach is still sitting at 500RPM when off but displaying the correct RPM when on and running. Any other suggestions?

I've fixed the lean condition and all the bad drivability issues I was having. Unfortunately I still have parts of the car that are going to annoy me until I fix them. One of which is the Offset of 500 RPM.

The fix for the lean condition was just altering the sealant for the EGR. I believe the source of the problem was that I didn't really block off the EGR passage appropriately and so had to go back in with more Silicon sealant and place it between the main EGR passage and the two smaller chambers that follow back into the intake of the chambers.

I will make a new thread if it's not answered here in the next little bit. Unfortunately I do not have readily available computer access while I'm at my fiancee's. Just how it goes.
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