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Running Rich by Mylek
Started on: 01-20-2019 12:12 AM
Replies: 14 (802 views)
Last post by: Mylek on 02-13-2019 11:46 AM
Mylek
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Report this Post01-20-2019 12:12 AM Click Here to See the Profile for MylekSend a Private Message to MylekEdit/Delete MessageReply w/QuoteDirect Link to This Post
I have an ‘84 2M4. It running rich. I’ve replaced the Coolant Temp Sensor to the ECM. It seemed to have an effect. But, still runs rich. I’m thinking the Idle Air Control Valve or maybe the Fuel Injector itself. I’ll be checking those out on my next few days offf. In the meantime, if anyone has any ideas, you’ll have my undevided attention.
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ed55fl
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Report this Post01-20-2019 01:34 AM Click Here to See the Profile for ed55flSend a Private Message to ed55flEdit/Delete MessageReply w/QuoteDirect Link to This Post
Any codes ?
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Mylek
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Report this Post01-20-2019 06:15 AM Click Here to See the Profile for MylekSend a Private Message to MylekEdit/Delete MessageReply w/QuoteDirect Link to This Post
No codes now. Not since I changed out the Coolant Temp Sensor.
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ZCR1
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Report this Post01-20-2019 08:41 AM Click Here to See the Profile for ZCR1Send a Private Message to ZCR1Edit/Delete MessageReply w/QuoteDirect Link to This Post
Did the '84s have O2 sensors?
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Mylek
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Report this Post01-20-2019 08:46 AM Click Here to See the Profile for MylekSend a Private Message to MylekEdit/Delete MessageReply w/QuoteDirect Link to This Post
I believe so. Good call. I’ll check that this weekend as well. Thanks
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Mylek
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Report this Post02-02-2019 12:11 AM Click Here to See the Profile for MylekSend a Private Message to MylekEdit/Delete MessageReply w/QuoteDirect Link to This Post
Well, I dun gone and broke it. While replacing the IAC valve, I over torqued it. Snapped the threads off of the unit. I spent over an hour removing and cleaning that thing.
The IAC valve seems to be a difficult part to come by. Does anyone know of interchange options? Other vehicles that used the same IAC?
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JMTUT
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Report this Post02-02-2019 01:16 PM Click Here to See the Profile for JMTUTSend a Private Message to JMTUTEdit/Delete MessageReply w/QuoteDirect Link to This Post
Try rockauto. That's where I bought mine. https://www.rockauto.com/en...rol+(iac)+valve,6072
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JMTUT
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Report this Post02-02-2019 01:18 PM Click Here to See the Profile for JMTUTSend a Private Message to JMTUTEdit/Delete MessageReply w/QuoteDirect Link to This Post

JMTUT

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Let me know if you get it to run better. Mine still runs rich and I've replaced IAC, map, rebuilt the throttle body, changed o2 sensor, and replaced egr valve...
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AsaBergman
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Report this Post02-02-2019 05:45 PM Click Here to See the Profile for AsaBergmanSend a Private Message to AsaBergmanEdit/Delete MessageReply w/QuoteDirect Link to This Post
I have an 84 Fiero which ran absolutely terrible when I got it, it now runs 100% and gets something like 28 mpg even with all the hills here and doing 3000 rpm.

The IAC valves are common, as JMTUT said get them on rockauto, they're even on sale right now.
Make sure you didn't break the threads in the throttle body. I have a disassembled throttle body I could send your way if you ruined the threads although you'd need to rebuild it.

The first thing is the ECM temperature sensor, this is practically a must if you can't test the current one. Unless the car sat for a very long time I wouldn't worry about the injector right now as they're very durable.

I'd say both of you should change your spark plugs, wires, distributor cap and rotor, and ignition coil. Weak igniton = incomplete combustion, gives similar signs of running rich. If it's the original coil you'll need to grind off the rivets. If you're unfamiliar with it the cap and rotor is safe to do, you can't mess up the timing. Mark the wires by their position, they must go on the new cap in the same order. Also when you change the spark plugs blow compressed air at them before removal to clear out any gunk and rust. DONT skip this.
You may also have incorrect timing on the distributor although if this were the case you'd likely have difficulty driving it at all especially up a hill.


Here's a list of what I've done on my engine to get it up to 100%:
spark plugs, wires, distributor cap and rotor
ignition coil(still had the original)
thermostat and ECM temperature sensor(in the filler neck)
fuel filter
throttle body rebuild
replaced all vacuum lines
PCV valve, breather filter(circular thing on top of valve cover)
valve cover gasket
disconnect vacuum lines from cruise control(I never reconnected it)
disconnect vacuum lines from charcoal canister(this you should reconnect when its running properly)
MAP sensor, IAC valve
intake manifold gasket
engine computer(ECM): these can degrade/fail but my problem was that the previous owner put the wrong one in! they put in the ecm from an 85 automatic into my 84 manual.... it really didn't like that. moral of the story, make sure you have the correct ecm.
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Mylek
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Report this Post02-02-2019 06:16 PM Click Here to See the Profile for MylekSend a Private Message to MylekEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by AsaBergman:
distributor cap and rotor, and ignition coil. Weak igniton = incomplete combustion, gives similar signs of running rich.

I knew this. But, to showcase my inferior mechanical prowess, I didn't even think about it

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Mylek
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Report this Post02-02-2019 06:52 PM Click Here to See the Profile for MylekSend a Private Message to MylekEdit/Delete MessageReply w/QuoteDirect Link to This Post

Mylek

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Member since Dec 2014
Oh, the TB is clear. The threads are all clear of the socket.
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Mylek
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Report this Post02-12-2019 05:40 PM Click Here to See the Profile for MylekSend a Private Message to MylekEdit/Delete MessageReply w/QuoteDirect Link to This Post
Ok... New IAC is in. Started, but has a hesitation when it does. This isn’t new. Seems to run a little better. I’m still going to replace the coil, rotor, distributor cap, plugs and wires. Still seems a little rich. Not as bad though. We’ll see how things go after the ignition parts are replaced.
BIG THANK YOU to JMTUT for the link. It was a big help.
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AsaBergman
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Report this Post02-13-2019 05:31 AM Click Here to See the Profile for AsaBergmanSend a Private Message to AsaBergmanEdit/Delete MessageReply w/QuoteDirect Link to This Post
Assuming you disconnected the battery the engine computer won't properly calibrate the IAC until you drive over a certain MPH, something around 30mph or so. That may cause it to run incorrectly until then.
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theogre
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Report this Post02-13-2019 10:04 AM Click Here to See the Profile for theogreClick Here to visit theogre's HomePageSend a Private Message to theogreEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by AsaBergman:
Assuming you disconnected the battery the engine computer won't properly calibrate the IAC until you drive over a certain MPH, something around 30mph or so. That may cause it to run incorrectly until then.
> 35mph for ~ 1 minute and when changing IAC will need to reset the new one before you see good idle w/ or w/o discon the battery.

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Mylek
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Report this Post02-13-2019 11:46 AM Click Here to See the Profile for MylekSend a Private Message to MylekEdit/Delete MessageReply w/QuoteDirect Link to This Post
I didn’t know that. You guys are awesome. Thanks.
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