'Missing' in action

[ShoREV]

It’s been having an intermittent miss at idle for about 3 months or so and it showed up when I had the local Auto Zone run the hand scope showing a misfire in 3rd cylinder. About 3 weeks ago it began to miss and get worse the longer I drove it. The check engine light came on the harder I drove it. When cold and at idle it seems to run fine. Increasing the throttle it misses more, seeming to run on 6 or 4 cylinders. And full throttle yields no more power. However when I ran some E85 through it (I know, it’s not FFV but it runs good on it) the engine light went off and seemed to clear up a little. I have seen on the web site from wires, COP, fuel filters, coil pack, clogged cats. HELP! I can’t afford to replace everything. I also had a pair of bullet mufflers(from a SHO memeber) installed after Christmas and one guy said 2 of 3 cats were out and the other guy that did the work said the weren’t since they didn’t rattle. After looking at this page; http://www.abcesso.com, you think maybe the E85 broke some debris loose and need to change the fuel filter?

 

[wuzzzer]

Dude, what the flip are you doing running E85 in a SHO?!?!?

Most SHO 'misfires' or stumbling idle are caused by a bad spark plug coil.

If the scope showed cylinder 3 to be bad, replace the coil.

You're worried about spending a lot of money replacing everything? Keep running the E85 and you'll be replacing a lot more.

 

[me6894]

ya E85= bad

 

[HotRodKid]

well lets clear this up about the E85

e85 in and of itself is great stuff, but it requires proper fuel system parts, and proper tuning

the fuel pump, plastic fuel lines, rubber fuel lines, FPR and injectors all have to be e85 safe, otherwise they can start to melt

also, the car has to be properly tuned to get the most out of e85, and technicly speaking, higher octane fuels will give you LESS horsepower, because they burn cooler

E85 also has a different "stoich" air fuel ratio, so you'll need to retune to get the most out of it

 

[St Louis SHO]

E-85 requires twice as much fuel than reg gas, so If your getting this code while running e-85, change fuels immediatley, then go from there, also as for # 3 misfire, it could be either cylinder next to it in the firing order, been there done that OBD II isnt as smart as you all think it is.

James

 

[ShoREV]

Ok, off the E85. Actually the problem is not as bad with the e85 but problem begain before I ran it. I heard a suggestion earlier to move the back bank coil #3 to the front so easier to change if ODBII is wrong like you say. ALso, may go ahead and change wires and back 4 plugs at the same time. Anyone know the time should take for a first timer to remove surge take and ect. to get to the back bank? One final note; when I hard ecellerate it seems to run on half the cylinders but smooths out at cruze idle. Still electric? Would having a full diagnostic be worth running on it?

 

[wuzzzer]

ALso, may go ahead and change wires and back 4 plugs at the same time. Anyone know the time should take for a first timer to remove surge take and ect. to get to the back bank? One final note; when I hard ecellerate it seems to run on half the cylinders but smooths out at cruze idle. Still electric? Would having a full diagnostic be worth running on it?

Wires? Spark plug wires? No offense, but between the E85 and wanting to change the wires, you'd do well to read up on some automotive 101 books.

(Hint: V8 SHOs don't have spark plug wires)

 

[SHOZ123]

It's either the coil of the coil wiring. The coil wiring loom in the back likes to melt to the valve cover. The insulation may be melted enough to short out.