Intermittent Problem, Running Poorly
Thread Starter
Tech Contributor
Joined: Oct 2008
Posts: 3,729
Likes: 190
From: Custer, WI
Intermittent Problem, Running Poorly
85 A4.
Every once in a while, the car will start, and run like absolute ****. Will idle, but its all over the map. It only does this like 1 in 10 times I start it, and seems to be completely random. It does it when its hot, cold, or anywhere in between.. During this time, its runs VERY rich. It will move, and at about 55 mph, my instant mpg is 10. When its running normal, my 55 mph readout is usually 28-30.
I'm thinking that its an injector thats clogged, so the other injectors on that bank just inject a whole ****load of fuel, to make up for the cylinder thats running lean.
What do you guys think?
Every once in a while, the car will start, and run like absolute ****. Will idle, but its all over the map. It only does this like 1 in 10 times I start it, and seems to be completely random. It does it when its hot, cold, or anywhere in between.. During this time, its runs VERY rich. It will move, and at about 55 mph, my instant mpg is 10. When its running normal, my 55 mph readout is usually 28-30.
I'm thinking that its an injector thats clogged, so the other injectors on that bank just inject a whole ****load of fuel, to make up for the cylinder thats running lean.
What do you guys think?
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
Check wiring at ignition module. Replace ignition module. "
DTC 44 is rich exhaust.
If that one I would be looking at the O2 sensor and it''s wiring.Maybe a intermittant connection?
Thread Starter
Tech Contributor
Joined: Oct 2008
Posts: 3,729
Likes: 190
From: Custer, WI
OK now this is where stuff gets really ****ed up.
It has done this three times, don't laugh it sounds stupid but its true.
I went outside today, started the car, and it was running like crap. So i open the hood, look around for arcing or something, and when I DROP THE HOOD, IT STARTS RUNNING GOOD. ITS DONE THIS THREE TIMES. WHEN I DROP THE HOOD, IT JUST STARTS RUNNING LIKE NOTHING IS WRONG. WTF?
It must be from when i drop it that something connects? I have no fkin clue..this is some of the wierdest **** i've ever seen.
Edit: By drop i don't mean slam, just close.
It has done this three times, don't laugh it sounds stupid but its true.
I went outside today, started the car, and it was running like crap. So i open the hood, look around for arcing or something, and when I DROP THE HOOD, IT STARTS RUNNING GOOD. ITS DONE THIS THREE TIMES. WHEN I DROP THE HOOD, IT JUST STARTS RUNNING LIKE NOTHING IS WRONG. WTF?
It must be from when i drop it that something connects? I have no fkin clue..this is some of the wierdest **** i've ever seen.
Edit: By drop i don't mean slam, just close.
Pro
Joined: Mar 2006
Posts: 691
Likes: 0
From: Wayne NJ
85 A4.
Every once in a while, the car will start, and run like absolute ****. Will idle, but its all over the map. It only does this like 1 in 10 times I start it, and seems to be completely random. It does it when its hot, cold, or anywhere in between.. During this time, its runs VERY rich. It will move, and at about 55 mph, my instant mpg is 10. When its running normal, my 55 mph readout is usually 28-30.
I'm thinking that its an injector thats clogged, so the other injectors on that bank just inject a whole ****load of fuel, to make up for the cylinder thats running lean.
What do you guys think?
Every once in a while, the car will start, and run like absolute ****. Will idle, but its all over the map. It only does this like 1 in 10 times I start it, and seems to be completely random. It does it when its hot, cold, or anywhere in between.. During this time, its runs VERY rich. It will move, and at about 55 mph, my instant mpg is 10. When its running normal, my 55 mph readout is usually 28-30.
I'm thinking that its an injector thats clogged, so the other injectors on that bank just inject a whole ****load of fuel, to make up for the cylinder thats running lean.
What do you guys think?
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Pro
Joined: Mar 2006
Posts: 691
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From: Wayne NJ
Thread Starter
Tech Contributor
Joined: Oct 2008
Posts: 3,729
Likes: 190
From: Custer, WI
The module is like 300 dollars new, and you can hardly find used ones on ebay and when they are on there they are about 100-150. Is there a way to test it? Or convert it to a style where i could use relays?
I'd like to test it before i just throw one in there just for shts and giggles.
I think its strange how the hood closing makes it go away..isn't there a part that gets better when you hit it? I think its the MAF that you can tell is bad if you give it a smack. Not sure though.
I'd like to test it before i just throw one in there just for shts and giggles.
I think its strange how the hood closing makes it go away..isn't there a part that gets better when you hit it? I think its the MAF that you can tell is bad if you give it a smack. Not sure though.
Le Mans Master
Joined: Jul 2007
Posts: 5,043
Likes: 8
From: Tampa Florida
Thread Starter
Tech Contributor
Joined: Oct 2008
Posts: 3,729
Likes: 190
From: Custer, WI
If you have a code "42" pull the fuse for the ECM, leave it out for 30 seconds and then put it back in. Restart the car and see if the code 42 comes back...it shouldn't come back if the EST circuit is sound.....but if it does check to make sure the black "in-line" electrical connector(located near the brake booster) is still plugged in/intact and not grounding on anything. This electrical connector runs to and from the EST module. It has a connector on it so you can unplug it to check/set the "base" timing on the engine. You may also want to use a timing light to see if your engine is being allowed to electrically advance properly when your crappy gas mileage/poor running situation occurs. If the car is running with only 4-8 degrees of total advance this would explain the hard starting and poor fuel economy situation.
What would it be "grounding" on? I checked it and it was kinda loose, so I plugged it back in and it hasn't done it since I plugged it in. The clip on the connector is snapped off though, should i get a pigtail and splice it in?