Starts, immediately dies - new issue

[Snukulu]

Was finishing up the hardtop harness, pulled the driver's seat to work on the tilt mechanism and had to change the multifunction switch so it did sit for about a week (not unusual, never a problem before). I inadvertently ran the battery down pretty good and charged it overnight 2 nights ago. I buttoned up most of the dash but I left the rear wiper, defroster and foglights disconnected because Im finishing up a charging outlet in the lighter slot and need to get a grommet.
This morning I started it, gave it a little gas, and it actually rocked a little side to side. It wasn't violent but unusual enough that I turned it off, got out just to make sure nothing was under a wheel. When I tried to start it again, it immediately died. Tried it a few more times since, same thing.
Battery is fully charged.
It's not throwing any codes (key method).
I plugged the C1 C2 and foglight connectors back in in case that was some quirky thing (although it started and ran before I plugged those back in).
When doing the MFS I had a REALLY hard time getting the top part of the steering shroud out, but also putting it back on. I had to muscle it to where I felt like I would break something. I did watch videos. None showed a smooth way to get it off; they showed guys wrestling with it and one guy just said, "let's take this off" like it was nothing but didn't show how he did it. I did take out all 3 screws and moved the steering column up/down. There's not a lot of wiring in that area but wondering if I could have pinched something.
The key it started up with this morning is the original key, the one I always use. I did try the other two I have that aren't original. I checked the build sheet, and it doesn't say anything about a skim key. Figure it's still worth mentioning that while I was doing the MFS and hardtop wiring, I *was* using one of those non-original keys. (Just wondering if there could be some kind of quirk of it, resetting itself to a different key, but then figure it would start up with that other key this morning.)
I know others have mentioned the CPS; I don't know how to trouble shoot that yet so I just figured I'd start here.

 

[Snukulu]

I *did* also change out the gas cap ring to the locking one. Something I'd think would be irrelevant but who knows.

 

[macleanflood]

Do you hear the fuel pump run?

Cranking but not starting or not cranking?

Can you spray starting fluid or brake cleaner in the throttle body (assuming it's cranking) and will it start?

What's the battery voltage through the cranking process?

Sounds like fuel pressure to me...

-Mac

 

[05 White X]

Do you have the SKIM system on your jeep? as you where in that area and had a hard time removing and installing the covers.

 

[Snukulu]

Do you hear the fuel pump run?
—-I think so. I hear a hum (maybe for "one-one-thousand" seconds), then a click - sounds like normal startup

Cranking but not starting or not cranking?
—-Cranking, *almost* starting, then immediately dying

Can you spray starting fluid or brake cleaner in the throttle body (assuming it's cranking) and will it start?
(Please allow a short break while I YouTube "throttle body" then run out to the garage to locate it on my vehicle then go to the store and get some brake cleaner )

What's the battery voltage through the cranking process?
It was 12.2 when I checked it a few hours ago. Now 11.9. When I start it it throws up a bunch of numbers in the 10's then goes back to 11.9. Thinking this may be the issue but this is unlike any "dead battery" issue I've had (usually just the horrible cranking).

 

[Snukulu]

Do you have the SKIM system on your jeep? as you where in that area and had a hard time removing and installing the covers.

Build sheet and original window sticker don't list it

 

[cliffish]

Build sheet and original window sticker don't list it

is your key gray or black..I believe gray is a skim key.

 

[Snukulu]

is your key gray or black..I believe gray is a skim key.

Interesting! Definitely black.

 

[Dylan_See_TJ]

Does it crank and then die immediately? If you're able to keep it alive by opening the throttle plate either by hitting the gas or manually pulling it open, it might be your IACV going bad.

 

[Snukulu]

Does it crank and then die immediately? If you're able to keep it alive by opening the throttle plate either by hitting the gas or manually pulling it open, it might be your IACV going bad.

Keeping my foot on the gas kept it running. Is this something I can/should clean, or once it's acting up it's on its way out and I should just replace it?

 

[Dylan_See_TJ]

You can and probably should try cleaning it first. You can unplug the three sensors attached to the valve body, pull the throttle cable off, and then there's a couple of bolts that hold the throttle body on. Last summer, I pulled mine right off, took all three sensors out, cleaned everything, and put it back together - but I broke the IACV in the process, and so I just went ahead and replaced all three sensors (MAP, TPS, IACV) as well as the gasket.

If you try cleaning it, you can use either brake cleaner or, ideally, some throttle body cleaner. Just be real careful not to mess with the plunger when you're taking it out of the throttle body. It'd be nice to be able to just pull the IACV and clean that, but the bottom screw is right up against the manifold with the throttle body in place, so it's kind of a pain in the ass; I found it easier to just remove the throttle body. If it were me, I'd snag a replacement gasket and a bottle of throttle body cleaner, and try cleaning it without replacing anything if you can avoid trashing the old gasket taking off the throttle body.

Here's a photo of a throttle body for reference; the throttle cable arm is towards the bottom of the frame, the MAP sensor is on the right, the TPS is up top, and the IACV is on the left. In your engine bay, the throttle cable part will be facing the grille, and the TPS will be towards the windshield. You'll need to disconnect the intake and move it out of the way, unplug the three sensors, pop the little plastic end of the throttle cable off, and then take the four little bolts off that attach the throttle body to the intake manifold. Then you can give everything a once-over, reassemble, reseat the connectors, and give it a whirl. If you want, slap a picture of the IACV in here when you get it off, and I can eyeball if the plunger looks stuck out (it was on mine, which is why it was dying unless I had my foot on the gas). Oh, and if you need a new IACV (or possibly the other two sensors too), it might be worth trying to order at least OE if not OEM, because my parts-store-brand sensors kinda suck, and it's only been a year.

Sorry if that's a little confusing, it's actually a pretty easy process. For a less verbose explanation, possibly w/ some visuals, you can just google "Jeep TJ Throttle Body Cleaning" and scope out one of the numerous YouTube videos on the subject.

Hope that helps!

 

[Snukulu]

Was overthinking it. Started right up with the new battery. But, in looking things over, I came across these 2 loose connectors. I think the first one is for a/c (which I don't have). What's the other one?? x

You can and probably should try cleaning it first. You can unplug the three sensors attached to the valve body, pull the throttle cable off, and then there's a couple of bolts that hold the throttle body on. Last summer, I pulled mine right off, took all three sensors out, cleaned everything, and put it back together - but I broke the IACV in the process, and so I just went ahead and replaced all three sensors (MAP, TPS, IACV) as well as the gasket.

If you try cleaning it, you can use either brake cleaner or, ideally, some throttle body cleaner. Just be real careful not to mess with the plunger when you're taking it out of the throttle body. It'd be nice to be able to just pull the IACV and clean that, but the bottom screw is right up against the manifold with the throttle body in place, so it's kind of a pain in the ass; I found it easier to just remove the throttle body. If it were me, I'd snag a replacement gasket and a bottle of throttle body cleaner, and try cleaning it without replacing anything if you can avoid trashing the old gasket taking off the throttle body.

Here's a photo of a throttle body for reference; the throttle cable arm is towards the bottom of the frame, the MAP sensor is on the right, the TPS is up top, and the IACV is on the left. In your engine bay, the throttle cable part will be facing the grille, and the TPS will be towards the windshield. You'll need to disconnect the intake and move it out of the way, unplug the three sensors, pop the little plastic end of the throttle cable off, and then take the four little bolts off that attach the throttle body to the intake manifold. Then you can give everything a once-over, reassemble, reseat the connectors, and give it a whirl. If you want, slap a picture of the IACV in here when you get it off, and I can eyeball if the plunger looks stuck out (it was on mine, which is why it was dying unless I had my foot on the gas). Oh, and if you need a new IACV (or possibly the other two sensors too), it might be worth trying to order at least OE if not OEM, because my parts-store-brand sensors kinda suck, and it's only been a year.

Sorry if that's a little confusing, it's actually a pretty easy process. For a less verbose explanation, possibly w/ some visuals, you can just google "Jeep TJ Throttle Body Cleaning" and scope out one of the numerous YouTube videos on the subject.

Hope that helps!

View attachment 679204

Should this be a regular maintenance type of thing? I did watch a few YouTube videos and it seems do-able. But the type of thing I've got to budget extra time in for connectors not unplugging, rusted bolts, etc.

 

[Dylan_See_TJ]

Should this be a regular maintenance type of thing? I did watch a few YouTube videos and it seems do-able. But the type of thing I've got to budget extra time in for connectors not unplugging, rusted bolts, etc.

It's a quasi-regular maintenance thing - cleaning the throttle body, anyway. Not something that has to be done very frequently at all, but if it hasn't been cleaned in a long time it usually helps a bit.

 

[Snukulu]

You can and probably should try cleaning it first. You can unplug the three sensors attached to the valve body, pull the throttle cable off, and then there's a couple of bolts that hold the throttle body on. Last summer, I pulled mine right off, took all three sensors out, cleaned everything, and put it back together - but I broke the IACV in the process, and so I just went ahead and replaced all three sensors (MAP, TPS, IACV) as well as the gasket.

If you try cleaning it, you can use either brake cleaner or, ideally, some throttle body cleaner. Just be real careful not to mess with the plunger when you're taking it out of the throttle body. It'd be nice to be able to just pull the IACV and clean that, but the bottom screw is right up against the manifold with the throttle body in place, so it's kind of a pain in the ass; I found it easier to just remove the throttle body. If it were me, I'd snag a replacement gasket and a bottle of throttle body cleaner, and try cleaning it without replacing anything if you can avoid trashing the old gasket taking off the throttle body.

Here's a photo of a throttle body for reference; the throttle cable arm is towards the bottom of the frame, the MAP sensor is on the right, the TPS is up top, and the IACV is on the left. In your engine bay, the throttle cable part will be facing the grille, and the TPS will be towards the windshield. You'll need to disconnect the intake and move it out of the way, unplug the three sensors, pop the little plastic end of the throttle cable off, and then take the four little bolts off that attach the throttle body to the intake manifold. Then you can give everything a once-over, reassemble, reseat the connectors, and give it a whirl. If you want, slap a picture of the IACV in here when you get it off, and I can eyeball if the plunger looks stuck out (it was on mine, which is why it was dying unless I had my foot on the gas). Oh, and if you need a new IACV (or possibly the other two sensors too), it might be worth trying to order at least OE if not OEM, because my parts-store-brand sensors kinda suck, and it's only been a year.

Sorry if that's a little confusing, it's actually a pretty easy process. For a less verbose explanation, possibly w/ some visuals, you can just google "Jeep TJ Throttle Body Cleaning" and scope out one of the numerous YouTube videos on the subject.

Hope that helps!

View attachment 679204

thanks so much for this! it's going to have to wait when I can budget enough time for broken connectors