Running rich 92 c2500

[BowTieTilliDie]

ok so I did the TBI mod, seems like every since I’ve done it I’ve been running extremely rich, I’ve checked for gas leaks I’ve rebuilt my TBI and my my injectors seem to have a nice cone shape. I’m also having a rough start, and stalling out on cold starts aswell + plus surging rpm... took out TPS cleaned it, changed egr, did vac lines, new TBI gasket, brand new distributor assembly, I’ve done intake manifold gasket. I’ve spent so much time on this truck in the last few months;trying to just get it running right and something new seems to come up. If I could just get this running rich/rpm delt with id be happy. Is there something I missed? The whole top end of my engine is basically new..

 

[BowTieTilliDie]

Had to come out and look at my truck to tell you guys what else I’ve replaced: 02 sensor, PCV, engine coolant sensor. How do I test spark plug wires? And my map sensor?

 

[BowTieTilliDie]

From egr to this sensor ? Is this vac line in correct spot I notice there are two lines coming from sensor?

You must be registered for see images attach

 

[94burbk1500]

From egr to this sensor ? Is this vac line in correct spot I notice there are two lines coming from sensor?

You must be registered for see images attach

I can check on mine in a couple of hours when I get off work. I think that is correct, the other one just had a foam "filter" on it. I'll let you know.

EDIT: is the one that the hose is on flared at the end? if so, that's definitely the correct side.

 

[Schurkey]

ok so I did the TBI mod,

WHAT is "the TBI mod"?

seems like every since I’ve done it I’ve been running extremely rich,

HOW do you know that it's "extremely rich"? What is the O2 sensor voltage? What are the short- and long-term fuel trim numbers?

DO ALL THE CYLINDERS RUN? NO "DEAD" or "WEAK" CYLINDERS?

I’ve checked for gas leaks I’ve rebuilt my TBI and my my injectors seem to have a nice cone shape. I’m also having a rough start, and stalling out on cold starts aswell + plus surging rpm... ...Is there something I missed?

Connect a scan tool. Compare the commanded RPM with the actual RPM. Find out if the Idle Air Control is working properly.

How do I test spark plug wires?

1. Run engine in the dark. Look for corona effect on plug wires. If you see corona, the wires should be replaced.
2. Remove each plug wire in turn, test with ohmmeter. Anything over about 4000 ohms per foot of wire is indicating failure. Some wires are as little as 30 ohms per foot. Depends on the construction of the wire. Carbon-rope wires (most common) start out at about 2000 ohms per foot.
3. While each wire is off the engine for testing, look for burned or torn spots on the insulation.

And my map sensor?

Connect scan tool, look for MAP voltage or MAP pressure readings.

 

[BowTieTilliDie]

I can check on mine in a couple of hours when I get off work. I think that is correct, the other one just had a foam "filter" on it. I'll let you know.

EDIT: is the one that the hose is on flared at the end? if so, that's definitely the correct side.

Yes, the one it’s connected to is flared at the end. Thank you

 

[BowTieTilliDie]

WHAT is "the TBI mod"?


HOW do you know that it's "extremely rich"? What is the O2 sensor voltage? What are the short- and long-term fuel trim numbers?

DO ALL THE CYLINDERS RUN? NO "DEAD" or "WEAK" CYLINDERS?


Connect a scan tool. Compare the commanded RPM with the actual RPM. Find out if the Idle Air Control is working properly.


1. Run engine in the dark. Look for corona effect on plug wires. If you see corona, the wires should be replaced.
2. Remove each plug wire in turn, test with ohmmeter. Anything over about 4000 ohms per foot of wire is indicating failure. Some wires are as little as 30 ohms per foot. Depends on the construction of the wire. Carbon-rope wires (most common) start out at about 2000 ohms per foot.
3. While each wire is off the engine for testing, look for burned or torn spots on the insulation.


Connect scan tool, look for MAP voltage or MAP pressure readings.

The TBI mod I followed shaved down some metal on the top of the TBI to allow for more air flow, I did not make the holes any larger just shaved the metal off the top.
I can tell it’s running extremely rich because I can smell it, the exhaust smells rich, I catch smells of gas, maybe it’s just me. I don’t believe I have any dead or weak cylinders I’m gonna record a cold start up here and post.
The only scan tool I got is an OBD1 reader, yesterday I plugged it in, and just FYI I haven’t had a check engine light come on in forever, anyways I got code 33 MAf sensor signal voltage or frequency high during idle, and I got code 54 fuel pump circuit fault, or mixture solenoid fail/ ECM Fault, don’t even know where to begin with these codes. What scan tool can I get to check
This data?

 

[BowTieTilliDie]

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Here’s a link to a video I just made obviously it seems to be running fine, very minor hesitation and rpm surge abit but it can be much worse.

 

[Schurkey]

The TBI mod I followed shaved down some metal on the top of the TBI to allow for more air flow, I did not make the holes any larger just shaved the metal off the top.

Seems like a waste of time, effort, and enthusiasm.

I can tell it’s running extremely rich because I can smell it, the exhaust smells rich, I catch smells of gas, maybe it’s just me. I don’t believe I have any dead or weak cylinders I’m gonna record a cold start up here and post.

The most common cause of eye-watering, "rich" smelling exhaust is misfire. The entire cylinder load of gasoline goes out the tailpipe.

Because the oxygen did not combine with the fuel, the O2 sensor may report a false lean condition, so that the rest of the cylinders get a too-rich mixture.

"I" would be performing a cylinder-balance test to look for dead or weak cylinders. A vacuum gauge on the intake vacuum might be helpful, as would a real scan tool to verify the MAP sensor reading.

The only scan tool I got is an OBD1 reader, yesterday I plugged it in, and just FYI I haven’t had a check engine light come on in forever, anyways I got code 33 MAf sensor signal voltage or frequency high during idle,

Does your vehicle have a MAF sensor?

and I got code 54 fuel pump circuit fault, or mixture solenoid fail/ ECM Fault, don’t even know where to begin with these codes. What scan tool can I get to check
This data?

Follow the procedure for each code in the service manual.

I favor a used-but-usable professional-grade scan tool rather than brand-new consumer-grade junk. Other will disagree, and someone's sure to recommend a special cord plus computer software; and I've got zero experience with that.

Earlier today, I bought another Snap-On MT2500 "Red Brick" scan tool with domestic software to '99. The guy accepted my offer for $150. I figure I can't go wrong at that price--my similar MTG2500 scan tool is getting a little flaky.

 

[BowTieTilliDie]

Seems like a waste of time, effort, and enthusiasm.


The most common cause of eye-watering, "rich" smelling exhaust is misfire. The entire cylinder load of gasoline goes out the tailpipe.

Because the oxygen did not combine with the fuel, the O2 sensor may report a false lean condition, so that the rest of the cylinders get a too-rich mixture.

"I" would be performing a cylinder-balance test to look for dead or weak cylinders. A vacuum gauge on the intake vacuum might be helpful, as would a real scan tool to verify the MAP sensor reading.


Does your vehicle have a MAF sensor?


Follow the procedure for each code in the service manual.

I favor a used-but-usable professional-grade scan tool rather than brand-new consumer-grade junk. Other will disagree, and someone's sure to recommend a special cord plus computer software; and I've got zero experience with that.

Earlier today, I bought another Snap-On MT2500 "Red Brick" scan tool with domestic software to '99. The guy accepted my offer for $150. I figure I can't go wrong at that price--my similar MTG2500 scan tool is getting a little flaky.

Do you know of any good guides online to preform the cylinder test?

I didn’t think it had a maf sensor, I don’t even know what it looks like to be honest.
I’ll have to invest in this scan tool, I have a good obd2 scanner, was disappointed when I found out this truck was OBD1