Eight_Ball

Hey all,

So I'm running an '08 tc, turbo (mostly PTUNING parts) with an AEM FIC. I've bought the car with all of these parts installed. Car has had this issue, and I got the car tuned just a couple weeks ago, and the issue remains.

So anyways, the issue I'm having (and the prev owner did too) is that sometimes this car just won't start up. It'll keep cranking and cranking but won't turn over (it did backfire once or twice if you kept cranking for a while, but that was pre-tune, never went that far cranking post-tune so I'm not sure if it still does that). Taking the key out for a few seconds (or just keeping it in ON for a little while) and trying again seems to usually fix it, but sometimes it takes a couple more tries yet (so at times can take a while to get going)

The annoying part is, is that there is no clear sign of when it will happen. Cold morning: sometimes will startup, sometimes takes a couple tries. Drive for a bit then restart: same random chance. Same if I stall it, or sitting long OR short periods, I've never found any way to know if it will/won't startup. The only thing I could think of is MAYBE like the battery is getting too old/worn, but that still doesn't explain the random occurences. Other than that, the wiring seems to look fine (pre-wired harnesses and such), but I'm not entirely sure what I should be looking for as to what may cause this.

Anyone have any ideas?

criminaltc

Alternator?

burgandybomber

iTrader: (1)

Alt, battery, fuel pressure, idle pocket of the tune... just throwing stuff out there. I have a fairly long crank but it always starts (ptuning kit). Just this morning it fired on the second crank. Stock took me about 3 cranks if I remember correctly. Most of time it takes about 6 post turbo. I think I have a video of my crank issue somewhere around here. But anyways, my long crank is consistent so it dosent sound like we are having the same problem. I have a brand new battery and walbro 255 but neither of those helped.

paul_dezod

Fuel table and MAF table during cranking are off. Experienced this first hand. If your cell values from 14 PSI down to the idle area of 4-6 PSI on the FIC are too lean it indirectly alters warm and cold starts....

Eight_Ball

Got a chance to test some stuff out, so now it seems that (post-tune I guess) I can keep cranking it and it WILL startup always (eventually). Earlier today took probably a good 10-15 seconds cranking to start, but it DID start and ran fine (Other times it just started up instantly like it should).

So is that still potentially tune related, or something else yet?

paul_dezod

See my post.

Eight_Ball

Alright, finally had a chance to get the values from my FIC (main problem is having to borrow a laptop).

Got my current values posted below here, wondering how far that is off (and if that's causing the problem?) and what those should be adjusted to (closer to the values you posted there I'm assuming?) based on my setup.
(Car is currently set/tuned for 15psi, and has 880cc injectors, if those are important for these values.)

Thanks a lot for the help

[EDIT: Image got messed up as attachment, just have a link here]

paul_dezod

Send me a copy of the cal and I will email you can some brief changes

paul_dezod

Bounced your cal back with some small changes. Keep me posted.

paul_dezod

Getting closer to solving the problem

xile6

ever fix this?

Eight_Ball

Due to aftermarket Cams, turned out that the camshaft position sensor couldn't get a good read (Due to a since-corrected design of the camshafts themselves) because of the magnetic nature of the sensor, and as such wouldn't start.

Got it to work perfectly by physically shaving down the plastic where it meets the engine (Trimming the inside edge so the metal sensor goes farther into the engine).

I got a rough picture here:


Note how I thinned only the useless "bracket-like" part of the sensor, not the sensor or the sensor's cylinder-y piece. I think I just used a file, and made sure the filing was straight so the sensor still went in straight.

xile6

So this only happen with an aftermarket cam?
I got a stock block and having starting problems.
Normally it about 6cranks then it starts up.
But about 40% of the time i crank and crank no start. Then stop and try again and it finally starts.
Done the resistor mod, but still have this problem and its bugging me.

**edit

Well i got it to start a lot better now.
I first the cam and crank wires were a bit loose at the boomslang harness. Car ran find just had problems starting.
I depin the wires and added new pins. Then removed the resistors.
I also 0 out the fuel map in the startup area (not sure if this was a problem too, doubt it since i remember trying this before.)

but with both of these done. It start good now.

05rs1

when i installed my BC 272's i had the same issue. the car would start with the stock ecu but not with my AEM EMS. after a very long time trying to figure it out, it was the 3 pins at the end of the intake cam for the cam sensor, were not out enough to be picked up by the sensor which is a requirement for the AEM EMS v2 to start the vehicle. i simply used a grip needle nose pliers to "wiggle" them out just a very small bit. and BAM the car started and finally ran fine.