Pacific Northwest Washington, Oregon, Alaska

88 4.0 running SUPER duper rich

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Old May 20, 2013 | 08:09 PM
  #1  
Westy's Avatar
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From: Chehalis, WA
Year: 1988
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Default 88 4.0 running SUPER duper rich

Title says it all, my 88 is running extremely rich and likes to die and burp a lot now... If I get on it, it blows straight black out the pipe. I'm getting HORRIBLE gas mileage, and really down on power. It's been doing it since I sank it at Tahuya (damn it). Any ideas?
I have replaced, fuel pump, plugs, wires, rotor.
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Old May 20, 2013 | 08:43 PM
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From: Oak Harbor, Wa
Year: 1987
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Originally Posted by Westy
Title says it all, my 88 is running extremely rich and likes to die and burp a lot now... If I get on it, it blows straight black out the pipe. I'm getting HORRIBLE gas mileage, and really down on power. It's been doing it since I sank it at Tahuya (damn it). Any ideas?
I have replaced, fuel pump, plugs, wires, rotor.
Might want to check O2 sensor.
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Old May 20, 2013 | 08:48 PM
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Originally Posted by 1987XJ
Might want to check O2 sensor.
X2
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Old May 20, 2013 | 09:13 PM
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From: some small town oregon
Year: 1989
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Map sensor or o2
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Old May 20, 2013 | 09:50 PM
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Ok thanks guys
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Old May 22, 2013 | 02:02 PM
  #6  
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Ok it wasn't the sensor any other ideas?
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Old May 22, 2013 | 02:21 PM
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From: Oak Harbor, WA.
Year: 1987
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Engine: 4.0 liter RENIX I-6, DIY Cold Air Intake, 2.5 FM Exhaust, 3 Core Radiator
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Which sensor did you try? The guys said to test your O2 sensor and your MAP sensor.

Is it running rich at idle, while giving it throttle or both?

Have you checked for vacuum leaks? Introducing extra intake air other than where its supposed to be will cause the computer to over richen the mixture.

Have checked all the basic things like a clean air intake filter and an un-obstructed air intake?

How about the Fuel Pressure Regulator? have you checked fuel pressure at the fuel rail. If its waaaay too high the regulator could be stuck or the vacuum line to it could have fallen off or be leaking.
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Old May 22, 2013 | 05:05 PM
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O2 is replaced I will check for vacuum leaks next. It runs rich 24/7
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Old May 26, 2013 | 12:07 AM
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when you say you sunk it, did you get water in the engine when you "sunk it"?
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Old May 26, 2013 | 04:11 AM
  #10  
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Originally Posted by trans_am7935
when you say you sunk it, did you get water in the engine when you "sunk it"?
It went under water at tahuya, I'm sure there's some pics on this thread, or in the April tahuya thread. And no no water in the engine, we pulled the plugs, and turned it over, no water came out.
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Old May 26, 2013 | 04:12 AM
  #11  
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I put a brand new air filter in it when I got home.
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Old May 26, 2013 | 09:31 AM
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check the vacuum line going from throttle body to the map sensor on the firewall. mine came loose and did exact same thing
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Old May 26, 2013 | 11:47 AM
  #13  
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From: Chehalis, WA
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Originally Posted by danXJ
check the vacuum line going from throttle body to the map sensor on the firewall. mine came loose and did exact same thing
Will do, I'm doing the water pump today so I'm gonna be all dug in anyways :P
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Old May 28, 2013 | 01:01 AM
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It saw a diesel and now it's copying it.
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Old May 28, 2013 | 05:39 PM
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Originally Posted by danXJ
check the vacuum line going from throttle body to the map sensor on the firewall. mine came loose and did exact same thing
This was the solution she lives again!!
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