[quadracer960]

First time posting, long time reader

Having a weird issue that popped up and im stumped. 2018 ss 1le HCI. Forgot to throw it on the trickle charger in the fall and tried starting it a few weeks ago. Didnt start first time but barelyyyy turned over. Tried it again for the heck of it and it fired up but seemed like it was missing which was weird. Took it for a drive to charge the battery and put fresh fuel in it but that didnt help. Then during that drive, a stablitrak light came on, service rear axle popped up and it started doing so weird things, like not being able to switch modes and stuff. Replaced the battery a week later and that didnt help.

SO i realized when i opened the door, i didnt hear the fuel pump prime. So i checked the fuse under the hood and in the trunk and they are fine. Other than that, anything else i can check before i limp it to the dealer 2 mins away? When i got on it during the first drive it felt GREAT but cruising through town not so much.

It ran perfectly fine and put it away running 100% normal on my last cruise in the fall. TIA

[bishopts]

No engine light? Or codes stored?

[ZLRob]

Not much you can check outside of the fuses. I made an access hatch set up for mine so I can do fuel pump replacements or services right there in my garage without needed to lift the car and drop the tank. It proved to be a very worthwhile mod as I had to go in there several times since for multiple reasons. if you have the means and resources, I'll recommend the same mod to you, but if not, take it in, as it sounds like the pump sounds highly suspect. They can and do fail out of nowhere.


Best of luck to you!

[bishopts]

Originally Posted by ZLRob

Not much you can check outside of the fuses. I made an access hatch set up for mine so I can do fuel pump replacements or services right there in my garage without needed to lift the car and drop the tank. It proved to be a very worthwhile mod as I had to go in there several times since for multiple reasons. if you have the means and resources, I'll recommend the same mod to you, but if not, take it in, as it sounds like the pump sounds highly suspect. They can and do fail out of nowhere.


Best of luck to you!

You can see low and high pressure fuel data from the pcm. You can also see fuel trim which will tell you how much demand is being requested.
The fuel pump driver module is above the rear diff. So since you have problems with the rear diff also you might get under there and find a rodent nest or missing wires that got chewed off.

[FLATOUTRACING]

Originally Posted by bishopts

You can see low and high pressure fuel data from the pcm. You can also see fuel trim which will tell you how much demand is being requested.
The fuel pump driver module is above the rear diff. So since you have problems with the rear diff also you might get under there and find a rodent nest or missing wires that got chewed off.

I had similar symptoms for over 6 month. Car left me stranded several times. Replaced the battery, added ground straps, replaced both fuel pumps (as dealer said no fuel pressure). At the end of all this it turned out to be the chassis control module in the trunk was bad. It was replaced and since that time I've driven 40,000 miles with no issues.

Check to make sure it's not the chassis control module before you start replacing the two fuel pumps. Lesson learnd on my end.

Hope this helps.

[sscentex]

Originally Posted by bishopts

You can see low and high pressure fuel data from the pcm. You can also see fuel trim which will tell you how much demand is being requested.
The fuel pump driver module is above the rear diff. So since you have problems with the rear diff also you might get under there and find a rodent nest or missing wires that got chewed off.

Does that work while cranking? I've got a problem that the first start of the day it takes the car 2-3 seconds of cranking before it'll fire and then it's fine the rest of the day. I'm suspecting the lines are bleeding down overnight but can't prove it. Seems to happen worse when the weather is cold.

[bishopts]

Originally Posted by sscentex

Does that work while cranking? I've got a problem that the first start of the day it takes the car 2-3 seconds of cranking before it'll fire and then it's fine the rest of the day. I'm suspecting the lines are bleeding down overnight but can't prove it. Seems to happen worse when the weather is cold.

Mine does that too. I suspect the high pressure system is leaking down. Possibly the high pressure pump but i havent really cared enough to check into it.

But yes you can see high pressure fuel data with just key on.

[ZLRob]

Originally Posted by bishopts

You can see low and high pressure fuel data from the pcm. You can also see fuel trim which will tell you how much demand is being requested.
The fuel pump driver module is above the rear diff. So since you have problems with the rear diff also you might get under there and find a rodent nest or missing wires that got chewed off.

Of course you can check that stuff but based on OP's post it really doesn't sound like he has the resources or means to be able to do that stuff. I could be wrong of course, but if he does then he has your post to be able to follow.


A bad fuel pump is fairly cut and dry to diagnose more often than not assuming everything is electrically intact.

[bishopts]

My first thoughts with it ran fine when i parked it is rodents messing up harnesses. Mainly because I've seen it so much. Gaining access to the fuel pump control module will give the ability to test the fuel pump electrically.
But also since i do this for a living i tend to group failures on my initial diag and find things that are common. Since there is "possible" fuel pump issues and eLSD, one thing they have in common is they are in the same 18in area of each other. Which happens to be in a place that's low and out of the way of humans. So... a great place for a nest.

[ZLRob]

Originally Posted by bishopts

My first thoughts with it ran fine when i parked it is rodents messing up harnesses. Mainly because I've seen it so much. Gaining access to the fuel pump control module will give the ability to test the fuel pump electrically.
But also since i do this for a living i tend to group failures on my initial diag and find things that are common. Since there is "possible" fuel pump issues and eLSD, one thing they have in common is they are in the same 18in area of each other. Which happens to be in a place that's low and out of the way of humans. So... a great place for a nest.

Well the CCM is what controls the fuel pump for Camaro SS. The CCM is also inside of the trunk and the wiring is out of the way. We have an FPDCM in our ZL1's and that thing is mounted on the eLSD. So I'm actually not going to rule a rats nest as being a potential issue unless they made one directly on top of the fuel pump or set one up somewhere else. Fine, lets just say it's lower on my list of causes which can possibly be causing his issue because anything is still possible. The ZL1's are more likely to have that issue because of the proximity of the module and wiring to the physical ground. Regular Camaro's lucked out.

[quadracer960]

I think honestly its the low pressure fuel pump took a dump. I do have a ODBII reader and since im being locked out of my job (oil worker) ill have all the time to start messing with it. Just was weird to me that when i realized when the door opens that the fuel pump doesnt prime like it used to. I think the eLSD and stabilitrak light popping up had to do with it miss firing since it wasnt getting the proper fuel pressure. Also seemed to be running leaner than normal on startup, 15:1 instead of the usual 11:1 or so IIRC.

Its stored in my garage and havent seen anything under it but its worth a look i guess. Cant rule anything out!

[ZLRob]

Keep us posted. I'm curious as to what is going on there.