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Bad coil packs?

fri3dchick3n

fri3dchick3n

New member
My 99 GTP has been having misfires lately. I've replaced the plugs and wires but still vibration when at low RPMs and I need to accel. I've read up that if it is a bad coil pack, the scanner should pull it up and tell you. I have the code P0300. Random misfire detected. I'm curious if there is a way to see if your coil packs are bad because I don't want to change them and "hope" it'll fix the problem.
 


Do you have any mods or vacuum leaks? Can your scanner tell you what kind of timing are you running?

One of my coils went bad a couple of weeks back and it was pulling like 4* of timing. You can buy just one coil and swap it with each one of the other 3 and see if it works. Buying just one is not that expensive and it doesn't hurt to have a spare one.
 
Whiplash Performance on here had a bunch of good ones for sale...and I bet they still have tons of them...on the cheap.
 
I only have a HAI and a shift kit as my mods for now. I did check out the vac line for leaks but ended up breaking it lol. I did black tape back, I think it'll be ok? And I just run down to schucks for a scan whenever I want to, it's just down the road from where I live.
 
A bad coil would not cause a random miss most the time. I bet your egr is sticking open a bit. Hook up to a scanner and have them look at the egr position if it is about 0 at idle theres your problem.
 
I'm sitting in the dealership right now here in anchorage, maybe I can have them scan it for me and check it out. And what if it is at 0? What exactly does that mean?
 


Alrighty well I let them know to check it out. Still going to be a while til I get the results but I will post them on here as soon as i find anything out. Thanks for the help! :)
 
I broke near the throttle body I think. Next to the MAF. I thought it was a rubber tube but was plastic :/. When there might be a possibility of a vac leak. What exactly should I look for? And how should I redo my cheap repair? Replace the whole thing?
 
You can get the entire vac sets from your local dealership...don't ghetto rig stuff...do it right the first time, trust me.
 


Yeah tape wont work on the vacuum lines. Take care of the vacuum lines first, put new hoses in there.

I was getting P0300 before I changed my coils. I changed them all at once to be sure, but P0300 never showed up again after that.
 
Alright, the lady here at the GM dealership says there is a problem with my intake valve/gaskets. Said my gasket is corroded.. Something like that. I will try to get a more legit explanation from them. Is this my vac leak?

Receipt says" 133463 inspected and found code P0300 for engine misfire. Found intake is leaking, needs to be resealed". Aprox cost- $965.00
The lady said that is was very serious. The car drives almost just fine, pretty good for a "serious" problem. The main reason for me being there was for a hub assembly, I tried to do it myself but I just was not able to remove this stubborn bolt off the brake caliper. And the reason for me changing that is becasue it was triggering my ABS and my TCS to be off. And they couldnt even fix that.. What would I need to do get those back working, I did notice that that wire was unplugged but for it being unplugged for such a long time, it got really dirty and what can I do to get that wire working again?
 
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She was talking about the lower intake manifold gaskets, they do get corroded a lot in these cars and leak water into the engine. Common symptoms are constantly having to add coolant that keeps dissapearing, coolant in your oil and of course, vacuum leaks.

The gaskets aren't that expensive, but everything and the dealership is always like that...

I'm not sure about the ABS light THAT I still haven't had to fix yet.
 
Whats the difficulty level on replacing that gasket? If I end up removing that manifold, I might as well as replace it with a P log then? And for that wire thats triggering my ABS and TCS, I think there is a type of aerosol spray used to clean wires and things like for the MAF. Anyone know the name of that?

Edit: Well they also did a recall: RELP ENG LEFT FT VALVE COVER GSKT AND RELOCATE WIRES 1 3 5 : \
 
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You replace the front EXHAUST manifold for a PLOG, we're talking about the lower INTAKE manifold here, they are two completely different things. I guess you could change the gasket yourself if you have enough skills. I personally wouldn't do it, I don't have the time and disposition to do that much work on my own.

They sell MAF cleaner spray at autoparts stores or you can use electrical connector cleaner.

The recall was for fire hazard I think.
 


Alright, well I dont have enough experience to do it then myself. And 1k for it to be fixed.. Ugh. And I'll try out the connector spray and try to get it working. I will post it if it did or didnt work anyway.

Edit: Oh and thanks for all the help :)
 
watch this vid, it shows how to remove the lim, plus lifters but you don't need to go that far. you can also take lots of pictures along the way and tag wires and hoses so you don't forget where things go. i wouldn't pay a grand to do this job myself, but thats me. or try a local shop, dealers just rape you.

http://www.cpaclubgp.com/misc/lim-gasket.html
 
Wow, thats one crazy video. Seems like he's done it quite a few times. I don't really see my doing that myself just yet. I noticed that he changes the valve cover gasket aswell, should I get that done also since it's right there? New rockers while at it? Time to make some phone calls and see what we get. Good video though!


Edit: Underground Performance, quoted around $525, 125 for material, $95 per hour. I provide the gaskets. They estimated 4 hours.. I have a feeling that it might take a little more than that.
 
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