Running Rich

PonyGTrider · Feb 2, 2023

Hi all I'm having an issue with a pathetic MPG and rich condition. I look everything with no success. I'm just working on troubleshooting an issue I encountered at the ECT sensor. The resistance on the ECT sensor is fine from cold to warm and vice versa. The problem I encountered is that the signal voltage coming from pin 7 KOEO is 2.43 volts and not the assumed (At least by me) 5.0 volts. I checked the signal voltage at the TPS connector and it showed 5.0 volts. I haven't checked yet the signal voltage at the ACT sensor connector but I assume it should be also 5.0 volts.
Did anyone had this issue of low signal voltage at the ECT, and how you guys solved that?
Could that be the cause of my rich condition and poor MPG issues too? definitely my exhaust smells like raw fuel and sometimes I hear and feel popping in my exhaust pipes under my seat.

Please help!!!

90sickfox · Feb 5, 2023

These computers are getting old and way past their time. First thing I'd do is send it off to ECUExchange.com and get it gone through and freshened up.

Monkeybutt2000 · Feb 5, 2023

Did you ohm test it? I had that issue with a brand new one. Put the old one back on after ohm test good to go.

PonyGTrider · Feb 5, 2023

90sickfox said:
These computers are getting old and way past their time. First thing I'd do is send it off to ECUExchange.com and get it gone through and freshened up.

Yeah I know what you’re saying.
Thank you

PonyGTrider · Feb 5, 2023

Monkeybutt2000 said:
Did you ohm test it? I had that issue with a brand new one. Put the old one back on after ohm test good to go.

Yeah I run a test to the sensor resistance throughout a full warming/cooling cycle and also it’s voltage throughout another warming/cooling cycle and the values on both tests where right on the money. So based on those results I called a good sensor.
Will keep searching for answers to my concerns of raw fuel smell at the pipes and poor MPG.
Thank you

AeroCoupe · Feb 5, 2023

So you probably saw this thread which is where you got the two attachments from.

ECT & ACT Sensor voltage

I checked my ACT & ECT Sensor voltage at the 60 pin connector and was only getting 4.65 Volts @ the ECU. I then proceeded to check the grounds and all were less than 1 Ohm. What could cause the ECU to only be giving me 4.65 Volts to these sensors instead of 5 volts. I also checked the sensors...

stangnet.com

Also in that thread jrichker explicitly says there is no VREF at the ACT or ECT and "Their operating voltage is supplied by the Analog to Digital Converter chips inside the computer."

With that see Post #2 in this thread. This is becoming a common theme with the age of the components of the ECU's on these cars. If you can borrow a known working ECU that would be free and an easy way to determine if the existing ECU is the problem.

PonyGTrider · Feb 5, 2023

AeroCoupe said:
So you probably saw this thread which is where you got the two attachments from.

ECT & ACT Sensor voltage

I checked my ACT & ECT Sensor voltage at the 60 pin connector and was only getting 4.65 Volts @ the ECU. I then proceeded to check the grounds and all were less than 1 Ohm. What could cause the ECU to only be giving me 4.65 Volts to these sensors instead of 5 volts. I also checked the sensors...

stangnet.com

Also in that thread jrichker explicitly says there is no VREF at the ACT or ECT and "Their operating voltage is supplied by the Analog to Digital Converter chips inside the computer."

With that see Post #2 in this thread. This is becoming a common theme with the age of the components of the ECU's on these cars. If you can borrow a known working ECU that would be free and an easy way to determine if the existing ECU is the problem.

Yes I read all of that and made all the sense to me. I have a spare ECU I bought long time ago, it is one of those “rebuilts” sold by Autozone but I opened it trying to identify it because there are no part numbers on the shell, I noticed the known leaky filter so I replaced it. I will swap that ECU and see if I notice any difference.
Thank you

General karthief · Feb 5, 2023

Does the spare ECU match the trans?
Why put a 'unkown' computer in, just send the original one in and get it checked out and then that takes the question out.
That's what I'd do, it's old, like me.

PonyGTrider · Feb 9, 2023

I installed the spare ECU and noticed no difference. Fuel consumption still too high, raw fuel smell at the pipes persists, and popping explosions in the mid pipes when cold.
Should I just replace both O2 sensors even if I don’t get any error codes? Injectors were serviced not too long ago.
I borrowed a MAF sensor (The one that supposed to be the right one. The one I have is F2VF-12B579-AA and the one I borrowed is F2VF-12B579-A2A and of course I have a 70mm Ford MAF tube…) no difference. I replaced the ACT and ECT sensors with a known good ones… No improvements
Must mention that after all of those changes I reset the ECM.
I don’t have access to a dyno or a tuner so thing are a bit more difficult.
What else could be my problem?
Could it be an injector problem?
I have an ajustable FPR with no leaking diaphragm and my timing is set to 10 deg BTDC….. What else??? …

Pinellas50 · Feb 10, 2023

My car was running very rich when I bought it and I went through the same thing you are now. I ended up putting in a new BAP sensor and that was the trick. A bad BAP won't throw a code(unless unplugged) and most people(myself included) don't have the advanced electronics needed to test it.

I only replaced the BAP after checking/testing all the other normal culprits listed in this thread and doing a smoke test to ensure I had no vacuum leaks. It was a gamble but worked for me.

PonyGTrider · Feb 10, 2023

Pinellas50 said:
My car was running very rich when I bought it and I went through the same thing you are now. I ended up putting in a new BAP sensor and that was the trick. A bad BAP won't throw a code(unless unplugged) and most people(myself included) don't have the advanced electronics needed to test it.

I only replaced the BAP after checking/testing all the other normal culprits listed in this thread and doing a smoke test to ensure I had no vacuum leaks. It was a gamble but worked for me.

The BAP sensor ha, never hear any discussions about that sensor going bad or what would go wrong when bad.

This boy just puts fuel like crazy enough to pop some explosions when raw fuel ignites in the exhaust pipes. I will search more about this sensor and learn about any potential symptoms.

Good for you solving that issue
Thank you for sharing

Running Rich

PonyGTrider

90sickfox

Wasn't a pretty sight...and I've got big hands

Monkeybutt2000

Mustang Master

PonyGTrider

PonyGTrider

Attachments

AeroCoupe

lube between the nut and the face. I know my lubes

ECT & ACT Sensor voltage

PonyGTrider

ECT & ACT Sensor voltage

General karthief

wonder how much it would cost to ship you a pair

PonyGTrider

Pinellas50

Active Member

PonyGTrider

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Running Rich

Wasn't a pretty sight...and I've got big hands

Mustang Master

Attachments

lube between the nut and the face. I know my lubes

wonder how much it would cost to ship you a pair

Active Member

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