Phantomwydd

I’m gonna make this another post cause I wasn’t clear. I have three codes. 15,23,45. Ones for rich fuel mixture, ones for intake air temperature, and the other is for coolant temp sensor. Ive had the iat sensor problem for awhile but it doesn’t affect my driving. then yesterday my car was running sluggish as hell, could hear the exhaust louder than normal also. I change out the o2 sensor and check the codes. To my surprise, it didn’t get rid of my rich fuel code. So next I check the coolant temp sensor to see that it’s aftermarket because the original gauge doesn’t work. I don’t even know how to fix it if it’s aftermarket, it seems to be connected straight to the gauge and not the car, but if that’s the case then it wouldn’t shows code. I’ve heard a coolant temp sensor can cause a rich fuel mixture. I just don’t know what to do, or where to start. I need help please. My car is a v8 305 5.0 CARB

sofakingdom

iTrader: (1)

12. Diagnostics Entered- Normal Code, with ignition on and engine off, indicates no distributor reference pulse to ECM.
13. Oxygen Sensor Circuit, check for a sticking or mis-adjusted TPS, check wiring and connectors for the O2 sensor. Replace the O2 sensor.
14. Coolant Temp Sensor/High Temp, but not overheating, check wiring & connectors for the coolant temperature sensor. Replace the CTS.
15. Coolant Temp Sensor/Low Temp, See above, then check the wiring connections at the ECM.
21. TPS/High, check for a sticking or mis-adjusted TPS plunger. Check wiring & connections between TPS and the ECM. Adjust or replace.
22. TPS/Low, check the TPS adjustment. Check the ECM connector, adjust or replace the TPS.
23. MCS, the MCS is open or grounded, check all wiring and connections, adjust or replace MCS.
24. MCS, a fault only indicated when the vehicle is in motion, disregard otherwise, check connections at the ECM & the TPS setting.
32. BARO Circuit Low, barometric pressure sensor circuit is low. Check wiring and or replace.
33. MAP Sensor, check the vacuum hoses from the MAP sensors and the electrical connections at the ECM. Replace MAP sensor.
34. Vac .Sensor/MAP sensor, signal voltage from MAP sensor is low, ECM substitutes a fixed MAP value & uses TPS to control fuel delivery. Replace MAP.
35. ISC Valve, Idle Speed Control error. Replace the ISC.
41. EST circuit, no distributor reference pulses to the ECM at specified engine vacuum, tach signal failure. Check wiring.
42. EST, bypass circuit or EST circuit is grounded or open. A bad HEI module can cause this code.
43. ESC/Knock Sensor, retard timing signal on for too long or the system has failed a functional check. System fault or failure elsewhere in system.
44. Lean Exhaust, check ECM wiring/connections, vacuum leak at the carburetor base gasket, vacuum hoses, & intake manifold gasket. Replace the O2.
45. Rich Exhaust, check the evaporative charcoal canister & its components for the presence of clogs or fuel. Replace the O2.
51. PROM, Make sure that the PROM is properly installed in the ECM. Disconnect battery & replace the PROM.
53. EGR valve, vac. sensor has received improper EGR vacuum. Check for failed diapragm or carbon in EGR pintle and manifold port. Replace EGR Valve.
54. MCS, voltage is high at the ECM because of a shorted MCS circuit and/or faulty ECM.
55. ECM, Be sure that the ECM ground connections are tight. If they are, replace faulty ECM.
61. O2 Sensor, sensor not responding, replace O2.


15 is for the coolant temp sensor. That's possibly what you have part of in your hand. It is separate from the gauge sending unit, which is in the driver's side head between the #1 & #3 spark plugs. Just replace it.

23 is for the mixture control solenoid. Sounds like it's probably unplugged. Look at the front pass side corner of the carb and see. It's blue. In fact, it's just barely partly visible in yout photo, and appears to be unplugged.

45 is rich exhaust. Unplugged MCS will cause that.

Fix the CTS and MCS, and see where that takes you.

Phantomwydd

so I plugged the MCS back in. But my car when I start accelerating has trouble. It made me check engine light turn off (codes are still there, it just turned off the light) so I’m not sure

sofakingdom

iTrader: (1)

And that "trouble" would be... ?

RARELY is the correct answer to a "trouble", disconnecting some critical part of something's control system.

So now, no codes? Coolant temp sensor all replaced and happy?

Phantomwydd

plugged the MCS in. And it turned my light off. The codes are still there though. But now that it’s plugged in, past 40 my carb is ticking loud and it’s bogging

sofakingdom

iTrader: (1)

Of course. That's what it's supposed to do. That's how the ECM controls the mixture; the duty cycle (% of the time) that the rods are in the rich vs lean positions, determines the mixture.

Some or even maybe all of those stored "stale" codes may go away after some # (50 maybe? not sure) of successful start / run / get up to temp / shut down cycles. You can clear them on demand by disconnecting your batt for some time, something around 5 min.

How's the new coolant temp sensor doing? Any problems there?

What's that?

Phantomwydd

So I realized. The aftermarket coolant temp sensor is connected to a aftermarket gauge inside. But the old coolant temp sensor was wrapped in electrical tape plugged in and set to the side. Any reason for this?

sofakingdom

iTrader: (1)

Stupidity.

Stupid people do stupid things. Any question about "why" is a one-way ticket down a rabbit hole leading straight to the chamber below the outhouse seat. Don't even bother going there.

Stupid people often "improve" their cars by doing things like ... aftermarket gauges ... because it "looks" "good", or "all the fast cars have that", or "my car [overheats, knocks, batt goes dead, fill in the blank] so I'd better add a gauge so I can watch the [temp, oil pressure, voltage, whatever] instead of fixing it". As far as any kind of "reason", it's entirely possible that some one or another of those 3 scenarios applies to the intellectually challenged individual that messed up your car. In my experience those 3 answers will cover about 90 - 95% of all such boneheadedness.

Get rid of the aftermarket gauge. Fix the stock gauge if it needs it. Fix the cooling system properly if in fact there's any kind of issue with it. Get a new ECM CTS and put it back where it belongs so that the engine's control system gets the inputs it needs to work right.