Weird hot start issue

[mike the snake]

I'm running the FB turbo kit, tuned with the Element Tuning Hydra standalone EMS.

Cold starts are consistent. Car doesn't jump to life, usually sputters a little, sometimes it takes 2 tries, but it always fires right up.

When the car is hot, usually, it fires right up, no issues. Occasionally though, it will long-crank and not fire.

I'll try starting 3 or 4 times with it cranking for a few seconds, but when it acts up like this, I know it's not going to catch and fire up.

The kicker is, all I need to do is let the car cool off for 2-3-4 hours, and it fires right up.

It's left me stranded a few times, where I just had to wait until the car cooled and then it fired right up like normal.

When this happens, the car is usually fully warmed up, probably idled in traffic for a bit, but in no way was overheating, or anything out of the ordinary, and most every other time the car starts without issue under the same conditions.

It seems heat related to me, and to me (I don't know too much about tuning) since the car runs fine and starts 49 out of 50 hot starts, that it's maybe tune related.

My tuner thinks it may possibly be something to do with the crank sensor wire, or something do do with wiring/hardware, and wants the car for a week to troubleshoot. The thing is though, he might not get the car to do this. It's pretty random.

Personally, I think it is tune related, and a simple adjustment is all that's needed.

I know that all I have to do is let the car cool off and it'll fire right up.

Because I'm running the Hydra, I am limited to who I can have look at my car, but I'm hoping maybe this might be something others have seen using the other tuning tools (OFT, Ecutek) have possibly experienced.

Any help or ideas would be appreciated.

[mike the snake]

Anyone??

[steve99]

Originally Posted by mike the snake

I'm running the FB turbo kit, tuned with the Element Tuning Hydra standalone EMS.

Cold starts are consistent. Car doesn't jump to life, usually sputters a little, sometimes it takes 2 tries, but it always fires right up.

When the car is hot, usually, it fires right up, no issues. Occasionally though, it will long-crank and not fire.

I'll try starting 3 or 4 times with it cranking for a few seconds, but when it acts up like this, I know it's not going to catch and fire up.

The kicker is, all I need to do is let the car cool off for 2-3-4 hours, and it fires right up.

It's left me stranded a few times, where I just had to wait until the car cooled and then it fired right up like normal.

When this happens, the car is usually fully warmed up, probably idled in traffic for a bit, but in no way was overheating, or anything out of the ordinary, and most every other time the car starts without issue under the same conditions.

It seems heat related to me, and to me (I don't know too much about tuning) since the car runs fine and starts 49 out of 50 hot starts, that it's maybe tune related.

My tuner thinks it may possibly be something to do with the crank sensor wire, or something do do with wiring/hardware, and wants the car for a week to troubleshoot. The thing is though, he might not get the car to do this. It's pretty random.

Personally, I think it is tune related, and a simple adjustment is all that's needed.

I know that all I have to do is let the car cool off and it'll fire right up.

Because I'm running the Hydra, I am limited to who I can have look at my car, but I'm hoping maybe this might be something others have seen using the other tuning tools (OFT, Ecutek) have possibly experienced.

Any help or ideas would be appreciated.

Think their will be stuff all people know anything about hydra ECU.

If it starts 49 out of 50 when hot its unlikely tune related.
you would think if its a sensor or sensor wiring the ecu should log a fault code but who knows with hydra.

more likely some heat related issue with electrics or fuel vaporization/vapor lock issue due heatsoak and it likely going to be hard to find being so intermittent.

[mike the snake]

Thanks very much for the replies.

I tend to agree, it is something like vaporlock or PW, something simple.

My tuner wants to go troubleshooting around the crank sensor wire and Hydra adaptor plug/wiring, but it just doesn't feel like something is working, and then not working (like a short or bad harness pin).

Especially since I know that all I need to do is wait a while and it fires right up.

[Ultramaroon]

Originally Posted by VitViper

I have seen this behavior on other platforms with upgraded (larger than stock) injectors. Typically it's because of some vapor lock combined with imperfect hot cranking injector PW. You can generally tune it out, but sometimes it turns into quite the battle as there's literally a very small window (very tight inj pw window) that is a "sweet spot".

Seems this behavior is also really common on returnless fuel systems. Every time I've converted a car to return style, the problem goes away (my theory is that since the fuel pressure has a way to drain back into the tank, it won't ever dribble out of the PI injectors -- which I believe is what really causes the issue, the fuel may be dribbling out a little and just vaporizing in the IM).

The fuel boils a little bit "somewhere" in the rail/line and, in a returnless system, that bubble has nowhere to go. If a port injector ever dribbles it's time to replace it. Makes sense in this car because it gets friggin HOT under the hood.

[Sportsguy83]

Originally Posted by mike the snake

Anyone??

When its failing to start, have you tried pressing the throttle and seeing if that starts it?

I also don't think its tuned related, unless the Hydra EMS is able to set particular IPW to a very specific range of temperatures, and you hit said temperature rarely and that doesn't allow your car to start at that very specific condition.

[mike the snake]

I have tried hitting the gas while cranking and it didn't help.

Everything is new, so I hope my injectors aren't malfunctioning.

I've made some mods to the front and I can say that my under-hood temps are lower than before.

One time, I started the car for 30 seconds to move it out of the garage to wash the car. I washed the car, and it wouldn't start after running for 30 seconds, and sitting for 1 hour. After letting it sit for a couple hours it fired up. In that instance, the car was Not hot, or even warm.

When we were first road tuning when it was first finished, it got good and warm, we went to the shop, and when I went to leave it wouldn't start. My tuner plugged his laptop in, and after a few different tries, he found,,,something,,,and it fired right up.

The other few times it hasn't started it was good and warm/hot.

I'm soon tuning for higher boost, and my tuner says he'll troubleshoot the starting issue then, but like I said, he may not ever get it to act up.

[Sportsguy83]

So weird..

[Ultramaroon]

Hitting the gas won't help. I understand it's a flood clearing feature which shuts off the injectors altogether.

At least that's what flooring it does. Sorry if I'm just being Captain Obvious.

[rb6freak]

This happens with my setup, as well as 3 or 4 others I know with FI (different setups, different tuners). Only when its hot. Try turning ignition key on (two clicks), on and off a few times without actually starting the engine. Fuel system will prime. This works for me.

Edit - If you want to make it act up (to try and solve it), get that engine bay real hot, go spin out and stall on purpose. You'll encounter the problem when you try and start up.

[mike the snake]

When we ordered up the FB premium kit (which came with 1000cc injectors) and the Hydra, the Hydra was pre-base mapped for the 1000's.

I inquired to FB, saying I knew I'd never run E85, and FB sent a different set of injectors (550's or 750's-not sure).

This set a bunch of fucked up issues into motion because the Hydra base map that should have gotten the car running, and have had the tuner well on his way to tuning, was mapped for the 1000's, car wouldn't even start, lots of scratching heads, then my tuner just started from scratch and tuned from point ZERO. This took WAY longer than it should have, but the tune now is pretty good, runs good, still not near the power it should be making, but this was my tuner's first twin, and I think he stayed on the safe side, tune-wise.

I know Phil at Element has had good success with the 1000cc injectors, as have many others (even though they're on pump gas only).

Soon I'm planning on tuning for higher boost, and making the HP that I built the car for.

One thought I had was to go back to the 1000cc injectors, start with the Hydra base map that was made for the 1000's, and start from scratch again and tune as Phil would, or even with his help, which he has offered.

Presently, the maps/tune/injectors is all different and all from my tuner. While the car runs good, and I know I have a safe tune, NOTHING about any aspect of the turbo install/Hydra/tune has gone smoothly. The car was at the shop for 4.5 months. I had to buy another car to drive because it took so long.

Not sure what to do now. I like my tuner, I think he's good, car runs good, just not making the power yet, and this weird starting thang.

I'm not driving the car much because I'm afraid it'll not fire up, so I usually just take short trips without stopping.

I'll get it figured out somehow soon though.

Thanks for the replies everyone.

[Tye300]

I have experienced the same symptoms since I changed my injectors. Same thing happens when the engine has been run. Cold starts have no problems, but for some reason, it sometimes has problems starting when hot. Im using ecutek. The difference is, i can make the car start by flooring the gas pedal as I crank the engine. I then purposely try to keep the revs up around 1500rpm. After a few seconds, the cold start high rev program starts and everything is normal.

[BarryPanick]

Originally Posted by Tye300

I have experienced the same symptoms since I changed my injectors. Same thing happens when the engine has been run. Cold starts have no problems, but for some reason, it sometimes has problems starting when hot. Im using ecutek. The difference is, i can make the car start by flooring the gas pedal as I crank the engine. I then purposely try to keep the revs up around 1500rpm. After a few seconds, the cold start high rev program starts and everything is normal.

Same thing happens for me. I'm running everything from the stage 2 kit, but with a smaller turbo so I didn't have to spend money on engine work yet. But when my car is started up it rips lol.

[FullBlown]

Originally Posted by BarryPanick

Same thing happens for me. I'm running everything from the stage 2 kit, but with a smaller turbo so I didn't have to spend money on engine work yet. But when my car is started up it rips lol.

It is in the tune Barry, I am still waiting for that tune file from your tuner.....