99 S70 GLT Engine B5254T [Vacuum leaks, hoses, Snorkel] Topic is solved

[scot850]

Here is a link for P1238:

viewtopic.php?t=30582

This point to the TCV being an issue.

It also points to a code for the fuel pump circuit having an error.

Neil.

[Grantkat]

Thanks - here is some more info.

I unplugged the MAF and cleared the code. I started the car. no chugging with MAF unplugged. NO ETS light. However the car would not stay running unless i kept it around 1500 rpm and the rpm was doing some hunting. if i let go of the gas it would bottom out. I let the car warm up and it settled on 900 RPM idle and was idling steady.
now I gave it some gas and let go and it bottomed out again and would not idle steady. in order to get it to ilde steady i have to ease off the gas. letting go fast it bottoms out.
After all of this, No CODEs

[scot850]

When you first turn the ignition on to Pos II, can you hear the ETM buzzing? If you can't hear it from the driver's seat you may need someone to do this for you and so you can stand at the front of the car to hear it better. If you don't hear it then there is an issue with it.

To control the engine, you need a working temperature (coolant) sensor. The fact the car does not initially start at a higher RPM than 900 would say the engine is not reading the ambient temperature correctly. So that may be a possibility. The sensor can be checked for resistance values v's ambient temperature.

The first thing I would expect to throw a code, the 2nd not. Also the ETM needs a temperature reading to set the car to fast idle when cold.
I've never thought where it gets that from, the coolant or ambient air sensor?

I would smoke the intake pipework again to check for leaks including a cracked intercooler.

Neil.

[Grantkat]

OK i ran some initial tests.

I didnt have a partner, later I will. I can turn the key and hear the throttle open and flip back. Do i need to hear a buzzing as well? if so I will check later with help.

the resistance of the temp sensor in SITU is 3390-4000 at 38-40 degree F. I put 2 meat thermometers on the engine near the coolant sensor one was 40 the other 38. resistance fluctuated between 3380 and 4000. hard to hold the connector and 2 probes at once

[scot850]

That would sound like it is ok to me for both items at least.

Neil.

[Grantkat]

Neil - you said P1238 is a possible turbo control valve issue or fuel pump circuit issue?

I checked the link,it went a few directions.

any suggestions on where to go next?
I have considered checking/cleaning the ETM.
I plan to run some MAF/No MAF tests today to see if it makes a difference.
what does it do with MAF and without is my next. However without the MAF yesterday i still had the rpm/stalling issue.

[abscate]

If you have flow or unmetered air it’s common to code P1238 without any fault in the valve.

Fix those induction leaks!

See story here

viewtopic.php?t=76489&hilit=80+inductio ... e&start=10

[Grantkat]

ok we may have solved the problem ...maybe.... we will see...

I replaced the air intake tube yesterday. I went back and double checked the tubes connection to the turbo plus the vac lines to make sure i didnt miss anything. There is a stop on the edge of the intake tube which keeps you from putting the tube on too far. You push the tube on the turbo inlet until that stop hits the lip of the turbo connection.

while checking i noted that the stop wasnt pushed up against the lip of the turbo. While I wasnt able to move the tube, i did go to loosen it and the 7 mm nut didn't seem all that tight thought again the clamp didnt move, i loosened, pushed the tube against the lip and tightened the hose clamp, and it took went farmore rachet turned than I had used to loosen it.

I started the car and within about 10-15 seconds smoothed and idled. I drove the car up and down my street several times and let the engine get to temp. it ran smooth, no hitches. idled around 8-900 in gear (auto trans) and 1000 in park.

i am going to go start the car and make small runs a few times to see how it behaves and make sure there is no more issues.

i will keep you posted

[volvolugnut]

If you have a code reader with live data reader, you can check the coolant temperature before starting and see if it is near ambient. You can also look at MAP and throttle position to see if they look reasonable.
Report readings here for sanity checking.
volvolugnut

[abscate]

ok we may have solved the problem ...maybe.... we will see...

I replaced the air intake tube yesterday. I went back and double checked the tubes connection to the turbo plus the vac lines to make sure i didnt miss anything. There is a stop on the edge of the intake tube which keeps you from putting the tube on too far. You push the tube on the turbo inlet until that stop hits the lip of the turbo connection.

while checking i noted that the stop wasnt pushed up against the lip of the turbo. While I wasnt able to move the tube, i did go to loosen it and the 7 mm nut didn't seem all that tight thought again the clamp didnt move, i loosened, pushed the tube against the lip and tightened the hose clamp, and it took went farmore rachet turned than I had used to loosen it.

I started the car and within about 10-15 seconds smoothed and idled. I drove the car up and down my street several times and let the engine get to temp. it ran smooth, no hitches. idled around 8-900 in gear (auto trans) and 1000 in park.

i am going to go start the car and make small runs a few times to see how it behaves and make sure there is no more issues.

i will keep you posted

I’m pretty convinced p1238 maps to induction leaks 99% of the time. The other 1% is a bad Iowa Potato front wheel bearing