Tell me the ohms on each injector, and did the chain break stand time

 

Ok, here's the injector resistances:

1. 1.7 ohms
2. 1.6 ohms
3. 1.7 ohms
4. 1.7 ohms
5. 1.6 ohms
6. 1.6 ohms
7. 1.7 ohms
8. 1.7 ohms

I'm assuming when you ask if the chain broke stand time, you mean, were all the marks lined up? Currently I have not re-verified it. I did however, have to go back into the engine after I installed the chains to get the tensioners to "click" to the correct tension. I double checked timing then and everything was good.

I pulled the injectors today and discovered what I believe may be the culprit. Which is good, because I was getting ready to pull the valve covers to check the timing. What did I find? Easy, injector #8, even though I thought I had verified it...was a counterfeit injector. Which would explain why my misses were always on the left bank...and why it appears the left bank reads "richer" than the right bank as it appears the left bank long term fuel trim hovers around -12, vs the right side at -6. (give or take) Here's a pic of the left bank injectors (#2 is the top injector in the picture):



I'm going to put the car back together with the injectors and coils from my SC project engine and see what happens. Fingers crossed everything clears up, and I'll know it was the crap injector. If it doesn't, then it's time to pull the valve covers and triple check the timing!

 

Sooooo.....swapped out the injectors and still have the same problem. Valve covers are now off, and as soon as it's cool enough to start working again, I'll get the engine timed up and we'll see where we stand!

 

Ok, bad news, good news situation. The timing is dead on, and that includes the HPFP cam as well. That's the bad news, I didn't find the 1 tooth off smoking gun....and that's also the good news, the timing is fine.

So, here I am about to send my car off to college with my son and this problem still eludes me. I have about 1 more week to put this to bed, but the reality is that I've been troubleshooting this issue since before I did the chains 2 years and 30K miles ago.

Someone has to have the answer!

oh yeah, I have a yellow top battery that runs about 12.6-12.7V overnight, so I don't think it's the problem, but I haven't ruled it out yet either. Maybe the cats? Maybe one or both of the exhaust solenoids are due? Maybe a short in the wiring harness? The problem is, none of these seem to fit the symptoms.

 

You've done everything that I can think of ... except ...
Crankshaft position sensor.
Assuming that the sensor is the two wire magnetic type rather than the newer three wire hall-effect sensor...
The output voltage is very low at cranking speed. If the CKP signal is not seen, the Cam position sensor may provide the location of #1 TDC.
However, that may require another rotation of the crankshaft.
Pull the CKP and check for contamination on the service end. It is a magnet after all and may attract oxidized iron particles.
Check the electrical contacts for contamination and/or oxidation.
Clean everything and put it back and give it a try.
If all else fails, replace the CKP with known good.

Keep us posted.

PS: Initial rough idle after start makes me think that accumulated fuel is present due to lack of ignition.
PPS: Reread your initial post. You mentioned CKP.

Bill

 

One possibility come in my mind: An small leak on pick up tube inside of fuel tank. Creates an "air bubble" in time to the fuel line what causes misfiring on start up?
A long shot but seen this few times.

 

Yeah, I swapped the Crank Pos Sensor before I swapped the cam position sensors. I too hoped it was just not picking up TDC correctly for ignition timing.

accumulated fuel after it struggles to start tracks…just not sure why. Thinking I may swap the battery….it still tests good and holds a charge, but it’s a yellow top and after plugging my GAP in every morning seems to be stable at 12.5V now. As I understand it, 12.4 is the “magic” number for these batteries.

maybe it just doesn’t have enough juice to properly fire?

 

this wouldn’t shock me, but in theory, if the tank is full there wouldn’t be any issues if there was a hole? Or am I remember my physics wrong?

 

Not sure if there are always an airpocket on sender- / low pressure fuel pump unit area? Anyway: It is a long shot...

 

So interesting update this morning. I hopped in to head to an appt, drove 25 miles, and decided to check live values before I shut it down. Oddly, both banks long term fuel trim was maxed out at -25.8%. Which then drove me crazy for the next couple of hours. Upon restart, the Bank 1&2 “too rich” codes had posted, so I cleared them and headed home.

when I got home I continued looking at live values, and discovered what I think may be the root cause…maybe.

just sitting, parked at idle, the battery voltage was 12.0-12.3 as measured by my GAP tool. I thought this had to be a mistake, so I pulled out the multimeter and tested the battery with the engine running…12.3 volts. I restarted the car a few times, wit the same results.

It appears that the alternator has failed. I can only assume it’s been failing for a while, even though I would watch the voltage jump from 12.5 to 14.2 when clearing codes a couple days ago. With that said, if the voltage is all out of whack, it could be all my problems are from an over/under voltage issue.

gonna grab a rebuilt from AutoZone today and install it. I’ll let you know what happens. I may swap the battery too…just depends how hard I want to cry at checkout.

 

Tapps33,
Vehicle with 5.0L will have a BMS Battery Monitoring System. Alternator is controlled via LIN and ECM.
If the control to the alternator fails, the default is 13.6V. 12.0-12.3 volts could be the BMS exercising the battery.
(Try disconnecting the LIN plug at the alternator?)
The battery voltage would have to be pretty low to affect the fuel trims.
The plastic air duct between the MAF sensor(s) and the engine is my first goto for too rich fuel trims.
Your fuel trim symptoms say air leak after sensor or fuel leak at injectors. (Or restricted air before/defective MAF sensor(s).)
12 volts should be sufficient for fuel trim controls.
However, poor/corroded grounds can make effective voltage less than apparent voltage.

Keep us posted.

Bill

 

Thanks for the response Bill! I agree with you on the rich condition. Especially since I went in and found my son over tightened the hose clamps on the intake plenum and they had all stripped. SMH. That said, I was looking at that as some other weird symptom of the hard starting problem.

I haven’t had a chance to restart the vehicle yet, but the battery was sitting at 12.3V before I started the alternator swap. When coupled with the fact that I can’t get them to charge higher than 12.6V, I figure it’s time to swap it out for a new yellow top.

it’s my hope that the alternator has been failing for a while and not charging the battery properly. Even though I’ve updated the battery type in the CCF, if the battery is constantly in a weaker state of charge, it’ll have enough juice to crank the engine over, but not enough leftover to properly run the electronics causing it to struggle to start for a second or two. I definitely noticed the voltage went from 12.3 down to 11.2 when cranking it (per my GAP tool display) which would explain its hesitation and random misfires on startup, until the alternator basically takes over.

I’ll repost later today, gotta hit the parts store….again.

 

Ok, update;

I have the new alternator in, and we're back up to 14.2-14.5V at the battery. I haven't checked amperage yet, but probably will. (as well as parasitic drain just t be sure). I took the battery into Autozone and they tested it under load and it dropped from 12.3 down to 11.1. Thankfully, it was under warranty so free battery time!! I installed the new battery and it still struggled to start the first time. It didn't struggle the second time, but after letting it sit for a few minutes struggle a little bit. That said, the battery was showing 12.0-12.2 volts. My guess is that the battery wasn't fully charged, and no, unfortunately, I didn't measure it before I installed it.

The good news is that I headed out on a 3 hour trip with the car tomorrow, so it'll have a long time to charge the battery up, and then I have my charger where I'm going, I'll throw the battery on and see if I can't get a good full charge on it.

I'll let you know how it does over the next couple of days, but I'm beginning to think this is the hard starting problem in a nutshell. Once the battery is full I'll be able to determine it for certain. I find myself comparing this to a chicken and egg scenario. Did the battery fail and that took out the alternator, or did the alternator fail and that took out the battery? Either way, both tested bad.

Stand by for an update in a few days. fingers crossed this finally solves it!!