Troubleshooting: Will not Cold Start (After Injector Replacement)

[JDG]

Car does not want to cold start. I have to crank it 4-5 times (10 seconds each time) to get the car to cold start. Fuel pressure is good in the line and in the DI fuel rail after priming once. This all started after replacing the cylinder #1 fuel injector. I did not replace the seals on the Cylinder 2-4 injectors (they were not removed from the head) but do not see any evidence of leaking. Car is pulling as strong as ever too with no issues with fuel pressure anywhere so I don't think it's a fuel injector/rail leak. I have also replaced the spark plugs to rule that out (so it happened with NGK 6510 and Brish Racing 2-step colder plugs).

Any other thoughts to what I might be missing? Could it be something intermittent that is failing like a sensor?

LPFP is new as well. Lots of variables have been changed around the same time this started occurring like new engine mounts (although I doubt those are the culprit).

 

[wetwea33]

Car does not want to cold start. I have to crank it 4-5 times (10 seconds each time) to get the car to cold start. Fuel pressure is good in the line and in the DI fuel rail after priming once. This all started after replacing the cylinder #1 fuel injector. I did not replace the seals on the Cylinder 2-4 injectors (they were not removed from the head) but do not see any evidence of leaking. Car is pulling as strong as ever too with no issues with fuel pressure anywhere so I don't think it's a fuel injector/rail leak. I have also replaced the spark plugs to rule that out (so it happened with NGK 6510 and Brish Racing 2-step colder plugs).

Any other thoughts to what I might be missing? Could it be something intermittent that is failing like a sensor?

LPFP is new as well. Lots of variables have been changed around the same time this started occurring like new engine mounts (although I doubt those are the culprit).

I don't have an answer for you but I did just order the brisk 2 step plugs... How do you like them?

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[JDG]

I don't have an answer for you but I did just order the brisk 2 step plugs... How do you like them?

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So far so good. My cylinder 1 knock decreased quite a bit (but I also went back to the OEM cold-side charge pipe since CP-E unit was making contact with radiator fan) so hard to say if they helped at this point.

Edit: They arrived gapped at .025-.026" so I didn't need to gap them which was nice.

 

[Erick_V]

You're full E85 now, right? I haven't tried tuning the EB motors myself but is it possible for you to mess with the cranking enrichment tables? I would try adding more fuel first, like 50%-100% more fuel in the cranking areas (below 400rpm?) and see if that makes a difference at all. Has the outside temp went down drastically since your switch to full E? That can change things, as I'm sure you know alcohol hates the cold and I see you're up North. I don't see spark being an issue unless you have a very old battery that isn't giving enough voltage.

 

[Rocketst]

I have forgotten so much crap over the years when replacing small things, is it possible you forgot to clip in a sensor or maybe accidentally broke one and it's not reading correctly? How's the car sound when it's trying to start? Slow or regular turning if the internals?

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[Rocketst]

Also, I did have an issue after reinstalling my fuel rail in my build where it took a few starts before it held pressure properly, which I know what your going to say, it makes zero sense. But after about 5-10 starts it starts Everytime. Not sure why it did this.

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[wetwea33]

Have you checked the battery voltage? Starter? Dumping in too much fuel on startup?

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[JDG]

You're full E85 now, right? I haven't tried tuning the EB motors myself but is it possible for you to mess with the cranking enrichment tables? I would try adding more fuel first, like 50%-100% more fuel in the cranking areas (below 400rpm?) and see if that makes a difference at all. Has the outside temp went down drastically since your switch to full E? That can change things, as I'm sure you know alcohol hates the cold and I see you're up North. I don't see spark being an issue unless you have a very old battery that isn't giving enough voltage.

I did not know this about alcohol and low temps - solid info. I wanted to rule everything out before I went to my tuner with a request to change the tune.

Have you checked the battery voltage? Starter? Dumping in too much fuel on startup?

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Battery is solid. While it is a lightweight AGM, it can run the starter for like a solid 60 seconds before noticeably slowing down (where I need to get my Lithium jumper pack to give it some help).

The car started up fine today after sitting for 12 hours. So it seems a bit intermittent. The more research I do, the more I think the issue is that I did not replace the injector seals on the 3 injectors I did not replace. This may be allowing the pressure to bleed down in the high pressure fuel rail too quickly resulting in not enough fuel pressure to start the car first crank. It just seems like when super cold, it needs a lot of cranks to get the pressure up. I may actually log this during my next super cold startup to look at the data closer.

Will report back. Thanks for all the ideas, it definitely helps the process having people to spitball with.

 

[JDG]

Couldn't get it started this morning. FRP Actual is 1600PSIG and LPFP is 100PSIG. Killed both my battery and my jumper pack. Cranks no problem. I'll see if my tuner can add fuel. It's currently 37F out and I'm running E85 in the tank.

 

[wetwea33]

Couldn't get it started this morning. FRP Actual is 1600PSIG and LPFP is 100PSIG. Killed both my battery and my jumper pack. Cranks no problem. I'll see if my tuner can add fuel. It's currently 37F out and I'm running E85 in the tank.

Have mitch add more fuel in during the cranking period like the other guy said. Flash point of ethanol is much higher. If you plan on running ethanol year round I would consider stick a gallon or two of 93 in when it's colder as it will help alot. You may need to raise your idle too.

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[JDG]

More fuel added in tune, still nothing. Car turned on for 4 seconds with fuel pump disconnected so I know I have spark. With fuel pump on I am getting nothing, not even a sputter.

 

[wetwea33]

More fuel added in tune, still nothing. Car turned on for 4 seconds with fuel pump disconnected so I know I have spark. With fuel pump on I am getting nothing, not even a sputter.

More fuel added in tune, still nothing. Car turned on for 4 seconds with fuel pump disconnected so I know I have spark. With fuel pump on I am getting nothing, not even a sputter.

Oof i wonder if your lPFP is dead.

 

[JDG]

Oof i wonder if your lPFP is dead.

IPFP? What's that?

 

[wetwea33]

Low pressure fuel pump

IPFP? What's that?

 

[slopoke]

Quick question. Did you go to a higher volume LPFP?

 

[Erick_V]

Quick question. Did you go to a higher volume LPFP?

I think I remember reading somewhere he has a DW330 pump

 

[JDG]

Quick question. Did you go to a higher volume LPFP?

Yes

I think I remember reading somewhere he has a DW330 pump

Correct, DW300.

Low pressure fuel pump

Doubtful, showing 100PSIG at low pressure signal point.

 

[slopoke]

Just thinking out loud here, but can a MAF sensor be installed 180 degrees out? If so, did you do anything with the MAF? Since I no longer have a Fiesta, I can't go out to verify.

 

[JDG]

Just thinking out loud here, but can a MAF sensor be installed 180 degrees out? If so, did you do anything with the MAF? Since I no longer have a Fiesta, I can't go out to verify.

Just checked, it’s installed correctly.

Just got it to start. I cleared the cylinders of fuel uses the gas/clutch method in case I flooded it earlier today.

Took maybe 3 seconds of cranking to start it.

Going to let it warm up and then check the warm startup using three different revisions Mitch sent me and see which is best.


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