No idle or run suddenly
 

Moving here rather than continuing in the general forum.

My girl stranded me on Tuesday blocking lanes in the middle of a busy road:facepalm:.

Other than a quick trip to top off the tank a couple weeks back this is the first time it has been out since early Nov. Ran fine then but only ran it 5 miles up the road. Fired it up Tuesday morning and the idle did seem a little off but it was in the 30's so I figured it was just being a little cold blooded. Drove it 25 miles into work, thinking back idle and just coming into the throttle did seem a little off but on the highway did a nice 60 to 130 pull just before getting off.

Fired it up to head out for lunch and as I got a couple miles up the road was acting a little odd not really wanting to idle but once it was going seemed OK. After lunch it would start but die quickly, after several tries I was able to keep it running by two footing it and keeping just enough throttle to keep it running. Tried to get it back the couple mile to work and that did not end well, now it would start stumble for a bit then shut down. Put it on the trailer to get it home.

No codes, strange smells or noises.
Battery is fully charged and strong.
All vac hoses and intercooler lines seem good.
Can hear fuel pump kicking on with ignition.
Supercharger is making running.
Only work done over the winter was removed the bumper to replace the cold side intercooler line.
At home still would only fire and run for a couple seconds then die.
While checking the intercooler piping I did disconnect the intake from the intercooler and it would idle and run.

I do have HPtuners log files from when it runs and dies as well as when it would stay running with the intake disconnected. Just do not see a way I can post the .hpl files here, I can send them in a PM though.

Any ideas on where to look next?

Thanks

Run a compression test see what you get.

Check for signs of rodents. They may have moved in over winter.

It runs with the intake disconnected from the intercooler? Maybe a problem with the intake or intercooler?

looking at your log with the intake pipe on the o2 mv are pegged @ 1100 on both banks and there is no short fuel trim data (probably because it hasn't run long enough). With hose disconnected it's the opposite and they both are 50-100mv and your short term only has a fuel reading on bank 2 showing 20% lean. Seems odd for both o2 sensors to crap out at once, so I am not sure that is the problem. Fuel pressure looks fine.

Yes, i think the wiring needs a close inspection.
The problem just showed up after winter storage.
The data sounds like multiple failures, which is unlikely. But electrical problems can look like that.

A few years ago I took a one week ski trip out west. When i got back I noticed my black firewall insulation was now torn and white in some places. next to my right strut tower was a nest with pieces of that insulation and some shredded paper towels. The critters work fast. Fortunately they chewed the firewall not my wires.

I just had it on the hoist doing an oil change last month but who knows hopefully none of those sneaky bastards got in there. I will get it in the air tonight to see.

Thanks for the ideas, now I have a direction to look.

Let us know when you find out! I was thinking aminals too. Little jerks.

Got it in the air, was almost hoping for a mouse nest because at least then I would know exactly where to start fixing. I also discovered it was not taking the intake tube apart that would allow it to run but just unplugging the MAF. Doing this allowed me to idle it over to the other side of the garage, but for some reason it kept the fan running for a few minutes after shutdown.

But no everything was completely clean, removed all the under panels and gave it a real good inspection for burnt wires or anything. The only thing I found was some slightly melted loom on the drivers side front O2 wiring, looked like it happened some time ago as the way the wires were tied it was not facing the exhaust. But I will fix and re loom with some high temp stuff I have.

https://i.imgur.com/CzMQaHf.jpg

Pulled all 4 O2 sensors they were all pretty black so I will pickup new ones tomorrow. I think I will also drain the tank and put 5 fresh gallons of 93 in just to make sure on that front. I did have about 3/4 tank of E30 mix that had been sitting since the beginning of Nov. before I topped it off a couple weeks back.

https://i.imgur.com/JQIrZ4E.jpg

Hopefully she will be up and running Saturday morning. Just in time for some more snow.:mad:

Pretty sure faulty O2sen. will throw code.

O2 sensors don't really matter until closed loop. the ecm probably checks for continuity, but I don't think their output matters when you first start the car.

now that my SS is tuned for E85 that's all I run all year why put 93 in your car ?

That is correct. Cold start the engine operates in open loop and uses Open loop EQ ratio table for fueling.

The O2 sensors should still be switching properly instead of locked one direction or the other. The melted wires might be causing a short.

I can only run about E50 even less when it is cold. Just do not have enough fueling to supply the higher volume required for running full E85.