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wcc wcc is offline
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Bad idle and black smoke

Long story short.... Car went from normal to quit in 15min and towed home. Starts and barely idles with black smoke. I picked up a CIS gauge but it was CIS compatible so I still need that tool. In the meantime I've replace a hose looked at the plugs and will be checking the cap/rotor and replacing the fuel filter and a few other minor things. In the meantime if any of you have any suggestions or comments on some other things to check let me know...

Here's a video of it right before it quit....

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Old 06-21-2011, 04:10 PM
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Last edited by wcc; 06-21-2011 at 04:16 PM..
Old 06-21-2011, 04:11 PM
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From the Pobst book:
Engine starts but stalls on idle:
1. Vacuum leak
2. Incorrect fuel pressure
3. Cold start valve leaking
4. Aux air regulator faulty
5. Fuel injectors clogged
6. Control plunger binding or fuel distributor faulty

Your car is definitely running rich. I would recommend removal of the intercooler and inspection of all hoses, followed by testing of cold, warm and boost control pressures.
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Old 06-21-2011, 04:28 PM
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Thanks 911nut! I've been looking for a vac leak. I replaced a hose that was a leak and that allowed the car to start again but still really bad. It always, even now starts right up but it's been a long time for the higher idle when cold so I've wondered about the AAR. I've also, more recently, having a dieseling issue and been looking at the injectors. So maybe it's a combination of a couple things. I removed the plugs and they all look similar so I don't think it's a fouled plug but I'm replacing them anyways. Never hurts.

I'm planning start on replacing..
air filter
fuel filter
spark plugs
intercooler o-rings
cap & rotor

I also plan on testing both fuel pumps and plug wires while I'm waiting for the CIS book and the CIS gauge. Hopefully I get this thing up an running before summer's over..
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Old 06-21-2011, 05:17 PM
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Quote:
Originally Posted by wcc View Post
Long story short.... Car went from normal to quit in 15min and towed home. Starts and barely idles with black smoke. I picked up a CIS gauge but it was CIS compatible so I still need that tool. In the meantime I've replace a hose looked at the plugs and will be checking the cap/rotor and replacing the fuel filter and a few other minor things. In the meantime if any of you have any suggestions or comments on some other things to check let me know...

Here's a video of it right before it quit....
So, during your ill fated ride, did you perhaps run at full boost for even a short period...or were you just tooling along being mellow and suddenly $hit happens? Could be several things, but I would follow 911Nut's directions to look first for the obvious vacuum/air leaks. And definitely check your fuel pressures (control and system). BTW. a faulty AAR won't cause your black smokin' crappy running condition in and of itself, unless it's got bad hoses leaking air.
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Old 06-21-2011, 06:53 PM
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Had the same problem the other day out of the blue. Next day checked all the fuel related CIS pressures and then it ran Ok. Only problem it was idle hunting alot. Leaned it up a little to get rid of most of the hunting. Kind of stange it was running perfect the prior day.
Old 06-21-2011, 09:25 PM
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wcc wcc is offline
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So, during your ill fated ride, did you perhaps run at full boost for even a short period...or were you just tooling along being mellow and suddenly $hit happens? Could be several things, but I would follow 911Nut's directions to look first for the obvious vacuum/air leaks. And definitely check your fuel pressures (control and system). BTW. a faulty AAR won't cause your black smokin' crappy running condition in and of itself, unless it's got bad hoses leaking air.
You're right it was on boost when it first happened. Long story short but it would only do it on boost starting in third gear working itself to second gear then to first, then it quit. I towed it home and replaced the hose from the intercooler to the AAR and then it started again just rough idle with black smoke and the fuel smell.

I also just ran a can of bg44k fuel system cleaner through the tank before. Maybe that loosened up too much crap or got a piece lodged somewhere? Hell of a coincidence anyways.

I will check the pressures when I get the tools to do it but in the meantime I'll be poking around in there to see if there's anything obvious.
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Old 06-22-2011, 02:44 AM
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Just a thought only because I've had similar problems in the past. Are you still
using(or does it even have)the oxygen sensor. If its still hooked up, unplug it and see if it clears up. My lambda computer screwed up and it pulls the car really rich at idle..stumbles on accel and sounds like its loading up. I have a WB o2 just to monitor the A/F ratio and I just so happened to have my laptop in the car when it happened to me..I unplugged it and drove on.

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Old 06-22-2011, 04:07 AM
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No O2 sensor. I have GHL headers, k27, Dansk exhaust. I used a LM1 to set my AFR and then it's disconnected. I don't have anything on there all the time. Been working great for years. I do recheck it every couple of years to make sure it is still in range.
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Old 06-22-2011, 04:20 AM
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I had this same issue last week and it turned out to be a wire that was going to the warm up regulator had fraud and was only letting small voltage through so not allowing it to work properly . We were talking real black smoke as running on cold start all the time. Sorted wire and sorted in a instant. May be the same as mine was as yours running perfect then ruff as a bears arse .
Old 06-22-2011, 10:40 AM
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Get an infared thermometer and shoot the exhaust header as it exits each of the cylinders. Be consistant and log the temps. See if you've got one or two cylinders running seriously rich...

If so, then you've got FD, Injector or Spark issues.

Either way, you want to check your pressures with CIS gauge. SP, CCP, WCP, BCP, etc... Maybe your WUR plug has come off or is bad, causing your car to remain in Cold Control Pressure? You could check this out by plugging the AAR plug into the WUR...

Oh yeah - - Nice Wheels!! - - Good Luck!
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Last edited by mooney265; 06-22-2011 at 11:07 AM..
Old 06-22-2011, 11:05 AM
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Good thoughts, guys, on the power to the WUR. Don't both the AAR and WUR plugs get their power through the rear fuel pump relay circuit (swapping plugs would work if you only had a bad plug, vs. complete loss of power further up stream).
For testing purposes, you won't see power to the WUR plug unless the engine is running (or alternately, forcing the pumps to run). A simple volt meter will tell the story. Hopefully that's all it is and the WUR is locked into permanent cold start mode.
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Old 06-22-2011, 11:21 AM
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Yes, and I had a bad plug [was working intermitently...] You know, that WUR plug is removed and replaced a lot, eventually, it could become intermitent. The AAR plug on my car was still in "brand new" condition... So, I simply use that one [The AAR has been removed on my car for years...]

A volt meter will tell you there is power there, but won't tell you if it's "coming and going" when the plug/wiring is slightly moved/jiggled... FYI...
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Last edited by mooney265; 06-22-2011 at 02:52 PM..
Old 06-22-2011, 01:10 PM
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Ok, I just tested the power to the WUR. I turned the key to the run position and put one lead on ground and checked the wire. No power. Then I disconnected the AAR lead with one wire still on ground and that wire shows no power. So I had the wife crank it over while I checked it and the power to both the WUR and AAR were only .12 volts. Sounds to low to me but did I even check it right? They are both the same so where would you look next?
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Old 06-22-2011, 01:40 PM
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Just a guess but it sounds like either a partial blockage of the WUR fuel circuit or a blown WUR diaphragm. Pressure test will diagnose blockage, fuel in the WUR vent will diagnose blown diaphragm. Faulty wire may cause same symptoms.
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Old 06-22-2011, 01:51 PM
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So I had the wife crank it over while I checked it and the power to both the WUR and AAR were only .12 volts.
Please clarify what you mean by having the wife "crank it" (keep it clean so as not to offend the younger members here).

Cranking is cranking....whereas engine running (consequently fuel pumps running) is something entirely different. Did the car start and run and you still got no voltage? To test, I would just reach behind the fuel head and pull the blue (or is it green) plug to force the pumps to run with the ignition key in the on position. That way you don't have to start the car to get the pumps to run (i.e., to energize the rear pump relay and send power to the WUR), and you should be able to see voltage at the plug.
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Old 06-22-2011, 01:58 PM
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I kinda chuckled when I wrote that too.. lol. I figured I didn't check it right. I only had a few mins to eat and leave so when I get home I will try again.

I'm still waiting on the cis gauge to check fuel pressure just looking around in the meantime.
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Old 06-22-2011, 02:27 PM
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What Mark said... Disconnect the blue plug behind the FD to get the pumps running.

Tip: you can "ever so slightly" disconnect this plug - - keeping it in the same position on the FD, but not allowing current to flow. Makes is very easy to "re-plug."
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Old 06-22-2011, 02:55 PM
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I unplugged that wire and I could hear the difference. I checked both plugs and they show over 11v so power doesn't sound like an issue. I have a new set of plugs I'll get in there tonight or tomorrow and just try it although I doubt a fouled plug is the issue. I'll probably just have to wait until the gauge gets here and figure out how/where to hook it up and learn this process. I'm a newbie at this CIS troubleshooting stuff..

Thanks for all the tips so far guys. If you can think of anything else while I'm waiting let me know and I'll check it out..
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Old 06-22-2011, 04:11 PM
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EDIT-Just re-read your last post.


Sorry I couldn't be more help on the phone. I'll check this thread so see how things are going.

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Old 06-22-2011, 04:25 PM
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