Well it's happening again.

[stugots]

2003 v8, Symptoms-
Occasional hesitation from a stop.
3/4 starts are rough.
Idle isn't smooth occasionally.

After having all coils and plugs replaced in November (?) by the dealer, I just brought it back for VCG. They also replaced all boots and spark plugs. Ran pretty good for a couple of days but now its running weird.

In the service invoice, it says they detected multiple misfires and stress tested all coils. It says all are "ok" so I'm stuck here..

Just looked for a vacuum leak to no avail, pulled the passenger cover to find a ziptie on the first coil. Also one coil is different than the others, same middle number but the top and bottom codes are different.

I guess it could be injector related? Idk, I'm just kind of stumped here. I really don't want to bring it back to the dealer so they can keep it for 5 days and say I'm crazy because there isn't a CEL. Any advice please.

 

[joegr]

I would start by checking the fuel pressure.

 

[stugots]

Alright, do you know what it should be? I need to go borrow a tester.

 

[joegr]

30 to 55 PSI, depending on manifold pressure.

 

[jrand]

I would start by checking the fuel pressure.

Really? bc i would ask the dealer why theres a fckin ziptie holding my coils together...
hit a bump and lose contact i would imagine, but who really knows

and i believe the coils on a v6 and v8 are different part #s, so that could be your issue with the #s being different. you might want to look that up and make sure you have the right part

 

[stugots]

Really? bc i would ask the dealer why theres a fckin ziptie holding my coils together...
hit a bump and lose contact i would imagine, but who really knows

and i believe the coils on a v6 and v8 are different part #s, so that could be your issue with the #s being different. you might want to look that up and make sure you have the right part

Well I think they broke the tab, the zip tie holds it on pretty tight. Wish they would've mentioned it.

It's the same part number but different batch numbers, either they cheated me out of a new coil or maybe used an old one off the shelf.

I'm waiting on my buddy for a pressure gauge, in the mean time I cleaned the extremely dirty tb and maf so we'll see.

 

[jrand]

yeah i dont know about that ziptie crap. i would take it back on that alone. now if it was some dudes backyard garage chargin you $10 and a case of beer thats a bit different.

good call on the maf/tb. dumb question: is your fuel always 91+? how old is the filter? and did you clear your kam and follow proper calibration procedures after all this work? if so, then check your fuel system. but i would imagine the dealer already checked that for you. i guarantee they didnt clear the kam tho

 

[jrand]

but then again i guess they do have a zippy on your coil, maybe they didnt check for fuel system..

 

[stugots]

^I run 93, I know the fuel filter isn't original but its not new.

I checked fuel pressure all is good, I also ruled out a leaky injector. It's been starting alright (knock on wood) and throttle response changed significantly. It's a little slower but more linear. I know your technically not supposed to clean the tb, but it was really bad. Hope that was the problem.

 

[jrand]

what about the kam?
you could change the throttle response easily if you cleared kam of all the data/specs from your old/unclean parts.

 

[stugots]

I didn't bother, it will probably sort itself out. Seems the tb or maf was the problem, I guess don't overlook the small stuff.