Engine will not stay running - Solved

[Robinjo]

Fixed: The fix was that the MAF plug and Fuel Injector plug were swapped. Apparently this is possible on the LSJ engines.

So after taking out the fuse box and cleaning everything of trans fluid and putting it all back together, now the engine won't start. The symptoms it's exhibiting:
-Will fire but run really rough and dies, runs for maybe 3-5 seconds
-Lots of gasoline coming out of tail pipe
-No fault codes
-Plugs seem to all be in place and connected.
-Ran before bringing in for cleaning
-No water used to clean, only rags/towels and acetone on the parts
-Sprayed connectors with electrical parts cleaner. Not on the MAF though!

I'm open to ideas. I'm stumped for the night.....

 

[Ross]

Electrical gremlins in your goblin. You have a loose connection somewhere.
Loosen the 7mm bolts in the fuse box, retighten them, reseating the electrical block.
Pull the OBD2 codes, maybe it will give you a clue as to what the issue is. Seems like the PCM isn't getting all the normal sensor data needed to calculate the correct fuel mixture.

 

[Robinjo]

The can position sensor 10mm bolt was loose and I tightened that. That’s another thing that happened.

I’ll try taking it all apart and back together again.

 

[Robinjo]

Took it all apart and reinstalled everything. Same condition.
-Takes a few more cranks to finally fire than normal, maybe 2 to 3 times longer
-Finally fires but runs rough for about 3 or 4 seconds stumbling and then dies
-Lots of fuel behind the car

Checked my codes again, only getting 3 (using Torque Lite app)
-P0443 - Evap System Issue
-P0449 - Evap Solenoid
-P0452 - Evap discrepancy between fuel and sensor

Would a dirty Mass Air Flow sensor do this? I did find a little trans oil on the air filter bottom.
Would swapped black/purple engine plugs do this? (I'll investigate this further)
Would tightening the black sensor and plug on the Cam Position Sensor cause this? It was loose previously and I tightened it (mentioned before). I didn't move or do anything with the actual metal part coming off the head over the trans).
Any other thoughts?

 

[Ross]

The MAF doesn't like oil.... they sell MAF cleaner at the auto parts stores.
Swapped engine plugs would probably not start.... but check the wire colors on each side of the connector. If the colors match, then you have the right plug.
Your OBD2 codes don't mention a cam position error, so probably good there.

If it was mine, I would hook up HP Tuners and look at the tables. I ran my engine, for the first few months, without realizing I had a bad MAP sensor. No OBD2 error codes, but some tables were showing missing data. A $30 new MAP sensor, and all of sudden my engine became a lot more powerful, and ran better. The original MAP sensor was still working, but the tube that went into the intake was broken, and it was measuring barometric air pressure outside the intake rather than inside the intake.

 

[Robinjo]

So I cleaned the MAF sensor and it got a little better, but not great. It started a little quicker and ran for about 20 second. It was still throwing a lot of gas out of the tail pipe though. I'm thinking to just replace the MAF and MAP sensors just to rule them out completely. Would extending the wires on the MAF sensor cause this? I did extend one of the wires in the harness to get it to fit right. This was done yesterday while everything was apart. I do have continuity from a point before the splice to the end of the plug. So the section I extended is getting continuity. Edit: Just checked and I'm still getting 12v on the wire that I extended.

Also, I do not have HP Tuners.

 

[Gtstorey]

Depends on how you extended it. A properly done splice is fine. I wouldn’t recommend anything but a soldiered connection for a sensor. Crimped connectors can work but seem to be more problematic. An improperly crimped connection with trans fluid in it doesn’t sound to good.

 

[Robinjo]

I used the solder heat shrink connectors. I’m getting continuity and 12 volts at the plug.

 

[Ross]

Our PCM will modify the short term fuel trims based upon what the Oxygen sensor measures in the exhaust.
So if it runs for 20 seconds now, will it run longer on each following start?

I won't spend money buying sensors, hoping to find the problem.
Your money would be better spent buying tools to diagnose the issues, or paying for labor with some shop that can provide a diagnosis.

Most shops don't spend enough time to find the exact issue, and do what you suggested, shot gun guessing at the possible issues, and replacing stuff and hoping they get the right one. So shop carefully, and try not to pay for shot gun diagnosis.

 

[Gtstorey]

It’s not the 12v ignition wire that you worry about. It’s the signal wires that increased resistance causes problems on. Check and confirm the resistance of the other wiring is approaching 0 ohms. The resistance should be pretty close to a similar size wire of equivalent length.

My bet is still on a.loose connection somewhere. Just because the 7mm bolts are tight on the fuse box does not mean the individual wires are making connection. Every time the fuse box connectors are disconnected, the looser the individual wires get.

 

[Robinjo]

It’s not the 12v ignition wire that you worry about. It’s the signal wires that increased resistance causes problems on. Check and confirm the resistance of the other wiring is approaching 0 ohms. The resistance should be pretty close to a similar size wire of equivalent length.

My bet is still on a.loose connection somewhere. Just because the 7mm bolts are tight on the fuse box does not mean the individual wires are making connection. Every time the fuse box connectors are disconnected, the looser the individual wires get.

How do I check the individual fuse box connectors?

I didn't mess with any of the other wires on the MAF sensor plug. Only the one supplying the 12V. All I had to do to extend them was cut them out of the loom. The pink 12v wire was the only one that required lengthening. Are you saying to check resistance across this wire?

 

[Gtstorey]

Try wiggling the wires bundled around the fuse box and see if you can get a change. But you almost have to find the problem to tie down the correct wire. I eventually pulled all the individual wires out of the connector blocks and re-sprung the tabs. I kept having various intermittent problems and this solved them on that end. I’m still having occasional problems at the bcm.

If you didn’t extend anything but the MAF power wire the rest are probably ok, but since the problem occurred about the same time, you could have a damaged wire or connector that is acting up since you messed with it.

 

[Goblinfanclub1234]

I had some issues with running really rich on my 2008 turbo and I had the 2 MAP sensors in opposite locations. I do now know if this applies to the LSJ though, the LNF has a 3-wire and a 4-wire map sensor. Could indicate a bad MAP.

 

[Robinjo]

I’m going to start re-springing the connectors this morning. I can’t think of much more as I didn’t mess with a lot. Oh, those needing to extend their MAF wires I came across this:

2005-10 Chevy Cobalt HHR MAF Extension Relocation Harness 2.0L Turbo LNF LSJ | eBay

This works on the LSJ, LE5, and LNF Cobalt and HHR Only. Works for 2.0L 2007-09 Saturn Sky and Pontiac Solstice as well. This 22" long harness will allow you to relocate your MAF sensor without having to cut your factory harness and solder in extended wires.

www.ebay.com

 

[Robinjo]

Played around with the wiring a bit today and things have improved but not great. After starting, which happens quicker it runs like normal for about 5 seconds. Then it idles rough and sputters to killing itself. Throttle input doesn't help and still with lots of fuel coming out of the tailpipe. I'm now getting the following codes. It seems someone else had this combination of issues but I can't remember the solution.
P0102 - MAF Sensor Fault
P0201, 02, 03 and 04 - Fuel Injector Pulse Issue #1, #2, #3 and #4

Anyone have any other suggestions from here?

Edit: A little more information. Unplugged the MAF and I get the same result as with it plugged in. I measured all the ports for volts and ohms with key on power after it dies. Something is going on here, I believe but I'm not good enough with electrical to know. Is there a secondary plug that the MAF wires bundle into somewhere?
Pink Wire: 9v & Over Limit Ohms
Black Wire: 0v & 9 Ohms Also, no continuity to ground
Green w/ Black Wire: 0v & 9 Ohms
Pink w/ Black Wire: 0v & 9 Ohms
Blue w/ Black Wire: 0v & 9 Ohms

 

[Gtstorey]

Check Ross’s Aldata and see what the diagnostic steps are for those codes.

 

[Robinjo]

Forgive my diagnostic illiteracy, but what/how do you do steps 1 and 2? Is 1 just pulling the codes?

Also, where is the Ignition Voltage 1 fuse? I do not see that listed on any of the fuses. A blown fuse would explain a lot.

 

[Rttoys]

Step 1 is the beginning of every Diag. “Diagnostics systems check” is turning the key to the run position and see if the CEL comes on then goes off. If it does, then the ecm/bcm are working.

step 2 will need a scan tool (not a code scanner) and watch maf to see what it’s saying.

 

[Gtstorey]

I have the tools to check the maf readings. Might be later in the week before I can run by though.

It looks like the maf code is for low voltage signal from the maf. Since this happened after you messed with the wiring around the fuse box, I still think that a loose connection on the fuse box or bcm is the likely culprit.

I just re-read your post 15 and you should have battery voltage on one wire, likely pink. You should have ground on two wires most likely and one of these should be likely black. Not sure what you are measuring resistance too for you ohms reading.
This is based on the later models wiring but yours is likely similar, especially the pink and black wires. If you want to post the wire diagram for yours from alldata, I can tell you more.

 

[Robinjo]

I checked all the fuse box connections for tightness and pushed out terinals. Fould nothing that was questionable. Also, checked all the fuses at the fuse box and BCM, no blown fuses.

Step 1 is the beginning of every Diag. “Diagnostics systems check” is turning the key to the run position and see if the CEL comes on then goes off. If it does, then the ecm/bcm are working.

step 2 will need a scan tool (not a code scanner) and watch maf to see what it’s saying.

Ok, my limited understanding of what the AllData is saying was correct.

I do have another question: Is there a similar plug to the MAF plug? My coloring schematic from the MAF plug does not match AllData, not close. I expect there to possibly be some minor differences, but all except one?
Coloring scheme: Mine (AllData).
A: Pink-ish (Yellow)
B: Black (Black w/white)
C: Light Green w/black (Pink w/black)
D: Pink w/black (Black)
E: Light Blue w/black (Tan)

I have the tools to check the maf readings. Might be later in the week before I can run by though.

It looks like the maf code is for low voltage signal from the maf. Since this happened after you messed with the wiring around the fuse box, I still think that a loose connection on the fuse box or bcm is the likely culprit.

I just re-read your post 15 and you should have battery voltage on one wire, likely pink. You should have ground on two wires most likely and one of these should be likely black. Not sure what you are measuring resistance too for you ohms reading.
This is based on the later models wiring but yours is likely similar, especially the pink and black wires. If you want to post the wire diagram for yours from alldata, I can tell you more.

I had found the schematic for it yesterday and can't today for some reason. The (italicized) above came from AllData. I'll keep looking and post it back here if I can find it. Edit: found it.....