[kjw86ca]

Hey guys,

Today I was driving my SHO and it was acting really weird. When I came to a stop the engine would kind of cough, or sputter, I guess. The RPMS would drop to about 4-500 and then go up to like 1 then down to 700 where it usually idles. As soon as I would step on the gas it would go away. I had the air off.

Anyway, it hasn't stopped doing it all day. I went to a parking lot and popped the hood while it was doing it and the engine kind of jumps around from back to front when it happens. You can also hear it making a sound like "puh puh...puh....puh" when the rpms start dropping...if that makes sense. The service engine light is not on so there is no codes I'm assuming.

Any idea what it could be?

-Kyle

 

[pimpin90GL]

try cleaning the MAF and checking all the connections, if that dosen't work, maybe try resetting the idle.
just something to try whlieyou wait for others to chime in

 

[rocketfast321]

plugs and wires maybe? Try resetting the computer

 

[1fast97]

There's no traditional plug wires on a V8 SHO.

That's a classic symptom of a bad coil. You're better off asking these questions in the Gen 3 sections over on SHOforum or on the V8 mailing list.

Anyway, try Napa or Murray's for a cheap coil.

 

[Bob Gervais]

It could be the IAC as well, since it goes away with application of the accelerator.

I'd try taking it off and cleaning it with some Berryman's spray or something.

Ian's right too, check out V8 SHO and do a search, you may find something there. Us SLO guys are futile against the great powers of the allmighty physics challenging SHO.

Kidding!

 

[pimpin90GL]

Us SLO guys are futile against the great powers of the allmighty physics challenging SHO

my mechanic says the same thing, that there is auto repair and then there is SHO repair. he used to have one so he has a love/hate thing with them. my favorite quote from him, "standard practices do not apply to these things"

 

[kjw86ca]

Well yesturday I was at a stop light and it sputtured for a minute real bad and then the service engine soon light came on. I took it to Auto Zone and it said "P0307 Cylinder 7 Missfire Detected." I went into the store and the clerk working said that it is probably a bad coil. (As mentioned above in 1fast97's post.)

So what can I do to fix this? I am also going to post this in the SHOForum like someone suggested so maybe I will get more replies.

Also, if anyone could help with like pictures or a good description on where cylinder 7 is located so I can find the spark plug and coil that would be appreciated. I'm guessing it may be up front because I know on my vulcan It was something like 1 3 and 5 where up front so on the SHO is it 1 3 5 7 are up front under the apperance cover or am I wrong???

Please help!!!!

-Kyle

 

[Bob Gervais]

Number seven is in the front, you're lucky it's easy to replace. It's the front bank, third from the left when standing in front of the car. Like this:


1 2 3 4


5 6 7 8


I would post the question to V8 SHO as opposed to SHOForum. There's much more traffic and know-how on V8 SHO.

 

[kjw86ca]

Hey Bob,


Thanks a million for the reply.

I had already posted this on the shoforum before I read your message. I'm not even a member on the V8 SHO mailing list. Only got two responses on SHOForum, however. One was about how the V8 SHO has no 60k maintence, however. Lol, but no, the guys at SHOForum are nice.

Anyway, so HOW do I change the coil? Any how to directions anywhere around the net? Pictures are helpful. :lol:

Thanks again,

-Kyle

 

[sixfofalcon]

Front coils are easy as pie.

Remove 4 appearance cover nuts and 2 bolts. Have telescoping magnetic retriever device handy to find the lost nuts/bolts.

Remove oil filler cap.

Lift front edge of appearance cover, and angle the cover up on the driver's side so you can get the cover seperated from the plastic wiring harness appearance cover on the passenger side. This is the hardest step, and it's not that hard.

Replace the oil filler cap (don't skip this step!)

Remove the three IMRC bolts and reposition the box on top of the intake runners for convenience.

Lift the front main wiring harness out of the brackets.

Remove the coil-to-harness connectors and locate the bad coil. The coils come out easily by removing the two bolts and lifting the coil. Inspect the coil for physical damage (look for cracks, give it a shake and listen for rattling.)

The rest is self-explanatory.

 

[DJFergi]

You should also check the rear main harness as well. My G3 did the same thing. I replaced all four rear coils and had the rear main harness insulated.

The valve cover gets very hot and eventually starts to eat away at the wires causing a short.

This will give you the dreaded misfire.

Once Kirk welded my cams and insulated the harness, the car ran so smooth, u couldn't even tell it was on. Well, except for the lovely V8 sound we have grown to love.

Later

 

[sixfofalcon]

I forgot to mention that the "cyl #7" bit of info could be misleading. The V8SHO is notorious for indicating the wrong cylinder in diagnostic codes. Several people have been misled when they checked the indicated cylinder and after hours of troubleshooting found that the problem was occuring at a different cylinder altogether. Failing coils cause a lot of RF and electromagnetic interference that can give all sorts of bogus info.

 

[kjw86ca]

Well I will try. I have read about the thing with the wiring harness...hopefully its not that...I bet thats not cheap to replace. :blink: So thanks for the directions!!!

 

[shoz123]

The rear harness only needs the insulation beefed up (if you catch it in time). If you car has over 50k and has not been tuned up it is time to clean the intake anyway. Of course your cams are welded correct?

If you live in the upper Midwest Murray's Auto Stores are the cheapest with the coils. About $60 each.

 

[shoz123]

The rear harness only needs the insulation beefed up (if you catch it in time). If you car has over 50k and has not been tuned up it is time to clean the intake anyway. Of course your cams are welded correct?

If you live in the upper Midwest Murray's Auto Stores are the cheapest with the coils. About $60 each.