97 Tahoe - Fuel In oil - Stall Condition

[exp500]

What code reader/App are you using? Most have to purchase the "advanced Sensors" Or pro version With GM advanced PIDS or whichever they call it.for $5. in order to read cam offset or graph selected sensors. Some auto stores "rent" fuel pressure guages. Amazon about $30.
Recommend you stay away from Stealership unless you want to spend $300-$1000.00. They had the time (1 hour) and did not properly diagnose your truck last time.

 

[TwoNeef]

I have dash command paid, never got the advance pid's on it, or used it in probably 4 years.

I have a elm 327 bluetooth obd2 reader I belive.

I usually use a hand held basic 140$ odb scanner, but it cant read cam offets.


And for fuel pressure gauges, are they pretty universal? Or are the threads a pita?

 

[exp500]

I Think you need the "small One", Most come with 2 adapters.
Update your Dash command and it will do most of what you will need. (no ABS or 4x4 codes)

 

[TwoNeef]

I Think you need the "small One", Most come with 2 adapters.
Update your Dash command and it will do most of what you will need. (no ABS or 4x4 codes)

Cheers thanks bud.

Yea Ill buy the pid package,

Ill get a fuel pressure tester , one that ill keep for life.

Get the results written on paper.

Skip the dealer.

Replace parts that I listed on the end of page 1.

 

[exp500]

Long Hose is so you can stick it on windshield and drive. Helps sometimes.

 

[Donf]

With the understanding that I am not nearly as knowledgeable as anyone else on the forum......

Your pump may be bad but if leaks back into the tank that doesn't account for the how the fuel gets into the oil. Unless there is a leaky fitting, the fuel line is closed from tank to regulator. And, if you are getting gas in your crankcase it seems to me that the leak would have to be at the regulator.

Also, I ran around for months with a bum injector, dumped fuel all around where the injector fit in the manifold (am I the only person who thinks that the method GM chose to use to hold the injector in place is less than confidence inspiring?) I never noticed fuel in my oil although I looked. May have had a bit but not enough to raise the fluid level or generate an odor. But then I think it would only leak sporadically and even then not a lot, whereas a leak at the fitting or leaky regulator would leak much more and continuously. Or so it would seem to me.

I bought this gauge from Amazon,

https://www.amazon.com/Detool-Pressure-Updated-0-140Psi-Adaptation/dp/B07GCKDF9X/ref=sr_1_36?keywords=fuel%2Bpressure%2Bgauge&qid=1648246314&sr=8-36

Worked fine and it has since been used on a 10 year old Golf and did the job there as well.

 

[east302]

With the understanding that I am not nearly as knowledgeable as anyone else on the forum......

Your pump may be bad but if leaks back into the tank that doesn't account for the how the fuel gets into the oil. Unless there is a leaky fitting, the fuel line is closed from tank to regulator. And, if you are getting gas in your crankcase it seems to me that the leak would have to be at the regulator.

Also, I ran around for months with a bum injector, dumped fuel all around where the injector fit in the manifold (am I the only person who thinks that the method GM chose to use to hold the injector in place is less than confidence inspiring?)

I’d agree with that, sounds like an issue with the new injector assembly. Looking through the throttle body, is it still dry in there? If it is, then the only other way I could think of to get fuel into the oil is a bad manifold gasket, maybe a cracked head right under an injector or an injector leaking and it seeping past the rings?

How does your coolant look? You said they did a compression test, right?

When you installed the MPFI, did you seat each injector once or did you remove any and reinstall them? The tabs are so small that I could see one breaking. The Delco/Delphi version’s instructions are pretty clear on not taking them out once installed.

To identify the source of the leak (regulator/return line, injector or check valve at pump) you’d install a valve in the supply and return lines. Pull the filter and put one there and there should be a union in the adjacent return line for that purpose.

You’d then check pressure, opening and closing the valves to isolate each segment and see which one causes the pressure to drop at the schradar valve on the intake.

1. Prime system, close inlet valve and turn the key off. If the pressure holds, then the injectors and regulator are good. The leak is in the supply at the pump check valve.

2. If it leaks, then it’s at the injectors or going back into the tank through the regulator.

3. Pressurize again, close the inlet and return valves, then key off. If it drops down to zero then it’s the injectors. If it holds, then it’s the regulator - fuel is leaking through the regulator but stopping at the closed return valve, holding system pressure above zero.
More out of curiosity than anything, it’d be interesting to see which cylinder is reporting the highest misfire counts.

 

[TwoNeef]

I’d agree with that, sounds like an issue with the new injector assembly. Looking through the throttle body, is it still dry in there? If it is, then the only other way I could think of to get fuel into the oil is a bad manifold gasket, maybe a cracked head right under an injector or an injector leaking and it seeping past the rings?

How does your coolant look? You said they did a compression test, right?

When you installed the MPFI, did you seat each injector once or did you remove any and reinstall them? The tabs are so small that I could see one breaking. The Delco/Delphi version’s instructions are pretty clear on not taking them out once installed.

To identify the source of the leak (regulator/return line, injector or check valve at pump) you’d install a valve in the supply and return lines. Pull the filter and put one there and there should be a union in the adjacent return line for that purpose.

You’d then check pressure, opening and closing the valves to isolate each segment and see which one causes the pressure to drop at the schradar valve on the intake.

1. Prime system, close inlet valve and turn the key off. If the pressure holds, then the injectors and regulator are good. The leak is in the supply at the pump check valve.

2. If it leaks, then it’s at the injectors or going back into the tank through the regulator.

3. Pressurize again, close the inlet and return valves, then key off. If it drops down to zero then it’s the injectors. If it holds, then it’s the regulator - fuel is leaking through the regulator but stopping at the closed return valve, holding system pressure above zero.
More out of curiosity than anything, it’d be interesting to see which cylinder is reporting the highest misfire counts.

You are a Legend!

So I replaced the air filter, then replaced the catalytic converters, replaced the fuel pump, fuel filter and the air filter and cleaned the maf sensor.

Never removed a injector once installed.

Vacuumed reading is -7 so says my cheap scanner.

Now it runs and drives and isn't gutless.

But now exhaust smells very rich so says my friends.

I can't smells as well I hit my head good and was bleeding out the ears. But I don't remember that.


Anyhow how should I tackle the p1345 cam, and crank correlation thing.

I'll get a fuel pressure reading later when I can access said tools.

 

[exp500]

A cheap bluetooth scanner here-

Helpful Links

Helpful links- If this is a successful post maybe it could be stickied! Here's the first- https://www.gmt400.com/threads/88-95-service-manuals.43575/ https://67-72chevytrucks.com/vboard/showthread.php?t=700011

www.tahoeyukonforum.com

 

[YukonGTmaster]

Will do thank you.

When I get back to my home town.

- Replace the fuel pump assembly (its needs to be done anyways)

- Clean the fuel tank

- Put a new fuel filter in(again)

- Replace the ignition coil

- Double check spark

- Check the fuel pressure reading on idle, and while engine is off, and time the leak down.

- Do another oil change


Take it to a dealer

- I will get the Cam retard checked, confirmed, and adjusted if needed.
- And ask them to double check if their is a leak in the intake, and to find a repair said leak.


Does that sound like a fair reasonable plan of attack?

Did the new MPFI Spider you installed, come equipped with a new Fuel Pressure Regulator?