abrupt CEL after tune up?

[1990LTD]

yeah..there's a leak. Pretty sure it's a vac leak, anyway..that line that split that seems to be rubber on the smog pump end and a small metal pipe coming out of the firewall. All of the fittings etc are still attached to the smog pump end and that's blocked/capped off, but the metal tube coming out of the firewall is open. Don't have anything I could cap it with.



the rubber hose in question might very well be circled there, but it's hard to tell when it's a shot of someone elses engine.

[1990LTD]

and the metal hose/pipe/whatever might not actually go through the firewall, it looks like it wraps behind the motor. oh well, taking it to the garage tomorrow and telling them i suspect a vacuum leak and i'll see where they take it from there.


fwiw, warm air (exhaust?) is coming out of the uncapped metal hose. started it, plugged the hole with my finger and it ran fine, took my finger off the hole and stall. might be a coincidence but i don't know. oh well, i'll drive it like this tonight (don't need to go far) and tomorrow morning it'll hopefully be rectified. I really hope it's just a matter of capping that off, but I dunno..

[1990LTD]

once again, thanks for your help gadget

[1990LTD]

wouldn't you know it...gadget73 was right. vac leak sealed, good idle, good accel, no check engine light or stalls.

[1990LTD]

All we really did was crimp the end of that pipe (which seems to feed into the exhaust system), so it's not perfect, and the engine light happened again a few more times on the way to work. I'm going to get somebody to weld the thing shut.

[1990LTD]

Anybody ever use that JB weld stuff? The stuff that you need to mix before using...it says it is good for up to a constant 260 degrees and the max is 300 degrees for 10 minutes. D'ya think it'll get that hot? I've touched the pipe in question after the car has been running for hours and it was only warm to the touch, so.. I'm probably going to un crimp the end and jam some of that stuff in there.

[1990LTD]

Well it's definitely not that hose/pipe that was connected to the smog pump..sealed tight. Gotta be somewhere else, and the fact that it only happened after the tune up makes me think it was something we did while installing the plug/wires....fuck.

Any thoughts on that? There are probably a million and one vac lines that run around either side of the motor that could've been hit/nicked/whatever so I doubt if that will give any indication..

[1990LTD]

The only stuff I know we did was try to remove the intake plenum cover (the 5.0 LITER EFI bit) and the air box. I say try to remove because one of the screws was stuck so I just tightened the rest up and left it on there. Air box came off because it's stupidly in the way, but it went back on..could that removal/installation have been screwed up somehow and caused a vac leak?

[1990LTD]

I was also told about the possibility that it's a sensor and not actually a vac leak because using the brake (brake booster using vacuum) doesn't stall it or make it any worse, really. What do you guys think?

When I start it, without touching the throttle, the car will rev up and down (almost to stall) and then eventually all the way down to a stall. I really fucking hope it's a sensor that was hit or something while we did the tune up

[gadget73]

Thats the air injection line for the smog pump. It feeds to the back of the heads. If you haven't destroyed the end, just get a rubber pipe cap and clamp over it.

[1990LTD]

Thanks. Yeah, nothing is getting in or out of either side of that line now. The engine doesn't seem to like idling when it's started cold and especially enjoys stalling when cold and put in reverse unless I'm on the throttle immediately. If I don't give it gas, RPMs dip and jump and it will stall on the 2nd or 3rd dip.

When the CEL is off, it's running better and doesn't feel bogged down, but it's still not running right...I know how the car drives and responds and it isn't normal. Also does not sound as "throaty", if that makes any sense...it sounds really dull/droning. It drove with the light off for a while on the way home from work tonight, and it idled with no light when I got home, but the idle is definitely too high.


Whatever the fuck it is, it goes on the computer in about 7 hours when the garage opens.

[1990LTD]

TPS.



I got a used replacement for now - Is there a particularly good one I should use as a permanent replacement? Is it the kind of thing you can upgrade or is there just one for this car and that's it?

[gadget73]

its just a replacement part. They used the same one for like 15 years on everything.

[pantera77]

At first I was like, "hmmm someone has painted there intake the same as mine. It even has a scratch in the same place!" But then I was like, "oh wait that's my engine"

Glad to hear you got it fixed.

[1990LTD]

haha, I tried to pick one of the cleaner ones I could find.


thanks. car is running great now..still leaking oil but the pan/gasket/pump/crap is on the way from rockauto now. i also want to get the smog pump and AC out of there because they're nothing but in the way now but they're not hurting anything.