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Discussion Starter · #1 ·
Hello gang, last week running a bit late for work, I popped into a gas station for a couple gallons of fuel to make it to the yard. I noticed that when I arrived home at the end of the day my 2001 coupe had a slight miss. Not a wire off of a plug miss, just a rough idle and rpm's were down to 500 on the tach. No codes were displayed, BasAzzBlue would idle and drive, but a tad sluggish. I hooked up a decent scanner and found the P0300, P0141, P0161. I followed some instructions on testing the O2 sensors and both of the after cat sensors had power, ground from the module (found that by testing power/ground at he car side of the plug) and the ohms of the heaters were 4.9. When cold, my a/f ratio is 12.6, after warm it leans out(?) to 14.6 and timing goes from 16 cold to 18 warm. I'm not in any way a tuning expert, I had just noticed these readings. I'm guessing those readings are the difference between open and closed loop? Anyhow, after cooling off a bit as it was 100 plus degrees outside, I restarted the coupe in hopes that something would be different and idled her up a bit for 1 or 2 minutes. I noticed the exhaust smelled of old bad gas. I shut her down. I'm not sure of where to go next, and at DC I have always been guided in the right direction. Can someone please let me know the next steps that I should take? I appreciate everyone's help, and many thanks in advance(y)(y)
 

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Discussion Starter · #2 ·
Last night I was reminded of a post that mentioned air leaks around the air bridge causing a similar issue. I did remove that piece to blow out the radiator and condenser just before my engine stumble began. I removed the bridge and looked through the throttle body and noticed what looked like molasses all over the inside of the intake manifold and a trail of it at the bottom of the throttle body. I have had a coolant leak from the coolant bypass connection to the bottom of the throttle body apparently, and was being drawn into the intake system. I repaired the leak, made sure the air horn was sealed at each end and no change in idle. It is still shuddering but no stall. Just trying to update. Pleeeze help!!!
 

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Discussion Starter · #4 ·
NORM! haha! The gas that was in the car was from a Shell station, and it was only $20 worth, which here in CA is 3 gals maybe? I did notice the stumbling issues on my way home from work that day as I didn't take the fwy to get home. I haven't put any fresh fuel in the car yet.
I do remember once before getting a tank of fuel from the same station that the car didn't like. It has been a year or two, but I stopped the occasional fueling there for the longest time.
Against all that I have read, I had the scanner delete the codes (as they were not enough to trip the mil) started the car and only the occasional misfire code came back (P0300)
Inreference to the condensation, I'm wondering if the a/freeze was being sucked into the throttle body from the bypass hose that is under the air horn where it connects to the tb? Maybe that is all of the molasses look inside of the intake?
 

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Discussion Starter · #5 ·
So, is my next step plugs and wires?
 

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So, is my next step plugs and wires?
It's really hard to diagnose a problem without physically being there in person, on here, you have one of the senses (sight for reading) working for you, you have no hearing, touch, or smell to work with.

Get a couple of your more mechanically inclined buddies together, maybe you can figure it out. Good luck.
 

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Discussion Starter · #8 ·
Hello Td. Yes. Pulled the TB off for the first time ever. Scrubbed that black ring from the body along with the edge of the throttle plate. Filed the body flat, and polished the mounting surface. One of the lower bolt were loose, maybe the pass side. The trail of antifreeze started in the middle of the air horn bellows, but suspecting the pass side lower bolt was loose rigged up a holder for a rolled up lint free paper shop towel, soaked it with the cleaner that I used on the TB and got as much of the “molasses” from the intake as possible without creating another problem. Reassembled, installed new Irridiums and Taylor wires. It’s better, not perfect. #7 is still the most active in the miss category. But it just leads the pack over 3 more cyl’s. Installed a fresh tank of fuel (there was zero little in the tank when I did) and added a can of BK-44. After testing the O2 sensors when I start the car, it will Idle up to IDK, 1200 rpm for a second and a half then mellow out to just above idle, then to idle in normal time. Last night I installed a new fuel filter from off the shelf that I’ve been meaning to do for 50k. I’ve driven it to work a couple of days and it’s better, but not as good as it should IMHO. Haven’t found another vacuum leak yet. Been using water instead of flammables. Not sure which paths to take now. No codes, just the slight misfires that aren’t worthy of lighting the mil.
 

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Drive a couple of tanks of gas through it with cleaner for injectors and top end before pulling your hair out. Give it a chance to clean up. Then if no improvement revisit. Above all stay positive.
 

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Discussion Starter · #10 ·
Thank you for the reminder TD. I reset the modules yesterday, so now I can’t do a lot with the scanner. The BG-44 is a great cleaner and have been using it for years. I would run straight Berrymans if the car would take it, lol. Thank you again for your help and advice. I will really like to put this problem behind me. Be blessed eveyone-mm
 
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