[sum_weirdo]

Sorry to get all British but I'm really REALLy frustrated right now. For the 2nd time this week my car is somewhere I'm not.

Here's a brief history:

OCT 2008 - I install a Vortech supercharger and tune. Everything works just fine until...

Sunday Morning - I've just installed a new VMP tune and temporarily wired up an external IAT sensor for it. Works fine for a short run to the mall and Partsource. I get home, I put some heatshrinkable butt connectors on the wires to finalize it and take the car out for a more extensive run. The car immediately idles like crap and dies less than a block from the house. Could not get it started again that day.

Monday Evening - Having decided I must have screwed up the MAF connector I brought a new one to the car and twisted the wires together by hand and sealed them with electrical tape. (I'd already reloaded the Vortech tune) So the car fires right up and runs like a top.

Wednesday Night - Having run the car since Monday but feeling weary I put butt connectors on 2 of the 6 wires and test the car. It runs. Good.

Thursday Lunch (today) - Having made the run to work without problems I put butt connectors on 2 more of the wires. Fired it up just fine, ran it for a minute or 2 and shut it off.

Thursday Evening - Leaving work, I go out to the car which has sat in the parking lot all day, turn the key and it fires up. For about 5 seconds. Then it DIES :frustrated:Can not get it started. Frustrated I rip out the damm butt connectors again and twist everything together by hand again. Still won't start. So I catch the BUS home wearing a leather jacket when it's 22 degrees Celsius out, now hear I sit sweaty and disgruntled wondering what the hell I'm gonna do next.

In typically ambiguous fashion there's enough evidence to support 2 different possibilities.
1. This week is the first time the car has been exposed to summer-like heat since the supercharger went on. Maybe the dunderheads at Vortech never put any thought into this tune they supplied and now it's a tad too rich. Both times this has happened it's been pretty warm outside.

2. Both times this has happened it's right after I've screwed around putting butt connectors on the MAF wires. It's a coincidence that's hard to ignore.

Tomorrow I drive the truck to work (the 31 year old truck that somehow is my most reliable vehicle right now :headscratch If the car starts and seems like it won't die I'll drive it home and scratch my head about the whole thing some more.

Any ideas? I need some insight here.

 

[stlwagon]

I have no idea... Though I'm having issues since I moved my IAT sensor. Coincidence?

 

[sum_weirdo]

I have no idea... Though I'm having issues since I moved my IAT sensor. Coincidence?

Interesting. What did you use to make the connections? I've got this half-formed theory that the computer is so sensitive to the MAF output that the slightest obstruction in the wiring will make it over-compensate.
Course the only hole in that theory is that the MAF harness has had butt connectors in it since I had to extend it for the Vortech install. Don't know why it would choose to act up now. But for that matter I don't know why the weather would have such an impact either, it wasn't THAT hot today. I'm about 3000 feet above sea level so the Vortech tune could probably stand to be leaner but they'd have to really have their heads up their asses to make it incapable of adapting. *sigh*

 

[stlwagon]

Interesting. What did you use to make the connections? I've got this half-formed theory that the computer is so sensitive to the MAF output that the slightest obstruction in the wiring will make it over-compensate.
Course the only hole in that theory is that the MAF harness has had butt connectors in it since I had to extend it for the Vortech install. Don't know why it would choose to act up now. But for that matter I don't know why the weather would have such an impact either, it wasn't THAT hot today. I'm about 3000 feet above sea level so the Vortech tune could probably stand to be leaner but they'd have to really have their heads up their asses to make it incapable of adapting. *sigh*

I soldered all of my connections.

 

[sum_weirdo]

Hmm. Been researching and I'm finding vague references to "clocking" the MAF sensor housing do reduce turbulence. Haven't found an exact science for it yet though. My MAF is directly behind the conical air filter on my setup, from the front I think it's clocked about 10:00 right now. Worth thinking about.

 

[sum_weirdo]

Studied the original instructions for the Vortech, it looks like the MAF should be perfectly horizontal whereas mine is diaganal. Whether that can actually prevent the car from starting in warm weather I have no idea but I'll try it.

 

[burnrubber4.0]

sounds like a goofy problem...but RTFM(read the effin manual), and you find the answer. id say its the maf position or the connestions. something is not right for sure. id start all over with the instructions....fill in anything u skipped...and do everything the manual calls for. if not...call vortech. get ahold of a shop...brenspeed, tillman. i dunno...id be frantic withou my car to drive! :happyhapp

 

[sum_weirdo]

Found a post somewhere that explained this pretty well. At idle there's isn't much airflow going through the intake but what little there is will take the path of least resistance. I looked closely at this picture of the duct from the manual and imagined the path a narrow airstream would take to get to the throttle body. Looks to me like it would go right past where the MAF is in the picture while mine is up away from that sweet spot. I'm probably lucky the car ran as well as it did for this long, all it needed was a good hot day. Nice how such a tiny detail can make such a headache.

Anyway here's hoping that does the trick tomorrow. It's supposed to be even hotter so I'm sure I'll know pretty quick if I guessed right

 

[burnrubber4.0]

i dont like that little filter cover. id rather have the heat shield. your idea makes sense though. hope it works. let us know

 

[sum_weirdo]

Well this morning when I got to work I clocked the MAF as indicated and started the car. No big deal there, it's been soaking up cool air all night. Though it looked like the idle RPM might have settled higher than it did before. The real test will be at 5:00 after it's been getting tanned by the sun all day.

Hey STLWAGON, it ocurred to me just now that you might be having a similar problem with your IAT sensor. At idle it might not be positioned to perfectly catch the airstream and reading a higher temperature than it should. Makes me wonder about where I placed mine too...

 

[sum_weirdo]

Well I'm home :bigthumbsupToday was easily the hottest day of the year so far. After work the car started up fine in fast idle and so I ventured on my commute. It idled rock steady all the way to Walmart where it promptly died when I shifted to Park (but it's been doing that since I was N/A with a Bama tune). About 20 minutes later when I came back out it started up okay in regular idle and drove home easily where it died in Park again I can live with that until my VMP tune is fully dialed in.

So clock your MAF boys and girls. Or BAD things will happen!

 

[stlwagon]

Interesting findings! My MAF is at approx 10 o'clock too. I'll play around with it.

 

[stlwagon]

I just check the instruction manual. It states 'Clock the MAF exactly as shown. (See Fig. 13-i.)'. This clearly shows it is supposed to be at 10 o'clock. Granted this is for the GT. The V6 instructions may be different.

 

[sum_weirdo]

I just check the instruction manual. It states 'Clock the MAF exactly as shown. (See Fig. 13-i.)'. This clearly shows it is supposed to be at 10 o'clock. Granted this is for the GT. The V6 instructions may be different.

Interesting. My instructions also have a picture with "clock the MAF exactly as shown", the difference is the intake tube assembly is resting flat on a table in mine (and this is where I got screwed up) but in the engine bay it rests at an angle. So what's 10 o'clock when it's flat is 9 o'clock in the engine bay.

With the 4.6 being taller maybe yours rests flat in the engine bay. Maybe take a look at it and try to trace the path the airstream would take, yours may be optimal where it is.

 

[sum_weirdo]

Well practically a year to the day and my car died again It currently sits in a Walmart parking lot, I'm gonna journey back there tonight after it cools down. Today was the same mix of hot and humid weather as last year, it'll most likely continue for a few weeks. I thought I marked the ductwork so this wouldn't happen again but I forgot about actually making sure the MAF is flat. I'll check that later. Then again maybe that was never the problem to begin with

 

[Mr. Ugly]

Studied the original instructions for the Vortech, it looks like the MAF should be perfectly horizontal whereas mine is diaganal. Whether that can actually prevent the car from starting in warm weather I have no idea but I'll try it.

It definately will cause a problem if your MAF isn't parallel to the airflow.

Your MAF will read an incorrect amount of air if it's not lined up properly.

Also, it's possible for bad butt splices to introduce additional resistance to the circuit which throws off your readings.

 

[jlawrence613]

Did you ever figure out the cause of the problem before you went FI? I dont have FI so im just flying by the seat of my pants here, but i dont understand why you would go FI when you were having the same exact problems when you were NA?