running rich

[SHO Squall]

Sounds more like your butterflies are sticking open, actually. If the light only comes on after a long, hard pull to redline, your IMRC might be crapping out. By the same token, you may just need to reset your PCM and get your tranny and intake synced back up.

 

[spragers]

That's the best news I've heard in a long time LOL... not that it's good that we both have the same problem, but at least it means we have something to work with.

The last time I had the car at the garage, they did the following tests:

"Scan for engine light on, codes P0172 - rich bank 1 - P0175 - rich bank 2. Upstream O2's clear (clean?) Perform self test, pass. Perform test on O2 circuit, pass. Inspection on air induction system and vacuum lines, inspection on PCV system, at this time no trouble found."

Time to read up on the IMRC over at V8sho.com...

If it is in fact the butterflies sticking open, then the engine is only running rich for a short period of time (I assume), which isn't as bad as it could be. I should be covered by my aftermarket warranty if the IMRC does go, so I guess for now I'll just wait and see.

Also, resetting the computer doesn't help, as I probably tried this 5 times or more last year. It's hard to keep the SHO away from redline

 

[venom]

spragers:
That's the best news I've heard in a long time LOL... not that it's good that we both have the same problem, but at least it means we have something to work with.

The last time I had the car at the garage, they did the following tests:

"Scan for engine light on, codes P0172 - rich bank 1 - P0175 - rich bank 2. Upstream O2's clear (clean?) Perform self test, pass. Perform test on O2 circuit, pass. Inspection on air induction system and vacuum lines, inspection on PCV system, at this time no trouble found."

Time to read up on the IMRC over at V8sho.com...

If it is in fact the butterflies sticking open, then the engine is only running rich for a short period of time (I assume), which isn't as bad as it could be. I should be covered by my aftermarket warranty if the IMRC does go, so I guess for now I'll just wait and see.

Also, resetting the computer doesn't help, as I probably tried this 5 times or more last year. It's hard to keep the SHO away from redline

Stuck butterflies will not throw a rich code....

You have too much fuel being delivered or not enough air...

As a shot in the dark try cleaning your MAF (gently of course) either that or you may have a bad injector (Stuck open) Does the motor run smoothly (no missing).

 

[99V8SHO]

spragers:
That's the best news I've heard in a long time LOL... not that it's good that we both have the same problem, but at least it means we have something to work with.

The last time I had the car at the garage, they did the following tests:

"Scan for engine light on, codes P0172 - rich bank 1 - P0175 - rich bank 2. Upstream O2's clear (clean?) Perform self test, pass. Perform test on O2 circuit, pass. Inspection on air induction system and vacuum lines, inspection on PCV system, at this time no trouble found."

Time to read up on the IMRC over at V8sho.com...

If it is in fact the butterflies sticking open, then the engine is only running rich for a short period of time (I assume), which isn't as bad as it could be. I should be covered by my aftermarket warranty if the IMRC does go, so I guess for now I'll just wait and see.

Also, resetting the computer doesn't help, as I probably tried this 5 times or more last year. It's hard to keep the SHO away from redline

I have an aftermarket warranty, too! Good until 100K. I figure I will reset the code, clean the MAF and then see if the code comes back. If so then I am almost positive I either have a sticking injector or a bad O2.

 

[SHO Squall]

venom:
Stuck butterflies will not throw a rich code....

You have too much fuel being delivered or not enough air...

As a shot in the dark try cleaning your MAF (gently of course) either that or you may have a bad injector (Stuck open) Does the motor run smoothly (no missing).

My bad. shrug I guess I was referring to the stuck butterflies WRT a high-speed run on the interstate from 50 up to 90. That will get your butterflies opening and closing a few times depending on how far into the throttle you are.

Of course, I also just learned a whole bunch this past weekend about the HO2S on the V8 SHO from a "slow" HO2S on my own car. They don't do their own self-diagnosis until the 50+ MPH range, which would also explain the SES occurrence after a quick run-up on the highway. burnout

 

[spragers]

The car runs fine for the most part, however there were a handful of times when it did not want to start - it would crank just fine, but there was no ignition. Usually if I let it sit for a minute and then tried again, it would start right up. No explanation from any of those three garages on that mystery, either.

Another month and I'll probably be bringing her out of storage, I'll be sure to keep a very close eye on what triggers the SES light and when it happens.

Also, I do have a code scanner with software on my laptop, it says it can pull real-time info from the computer. Is there anything I could look at to try to further diagnose the problem?

Thanks!

 

[venom]

spragers:
The car runs fine for the most part, however there were a handful of times when it did not want to start - it would crank just fine, but there was no ignition. Usually if I let it sit for a minute and then tried again, it would start right up. No explanation from any of those three garages on that mystery, either.

Another month and I'll probably be bringing her out of storage, I'll be sure to keep a very close eye on what triggers the SES light and when it happens.

Also, I do have a code scanner with software on my laptop, it says it can pull real-time info from the computer. Is there anything I could look at to try to further diagnose the problem?

Thanks!

Fuel trims (short and long term) would probably be useful.

 

[spragers]

Bringing back this thread, since I got the SHO out for the summer this past weekend. Took it for a "spirited run" in the country on Saturday, secondaries seemed to be working fine (I love the feeling when you hit 20 and get pinned back in your seat). Took it for about a 60 mile round-trip drive on Sunday, then to work two days this week (2-3 miles each way, mostly city driving), and so far so good.... tomorrow I'll probably be doing this though :headbang:

Put in a new air filter this weekend, Thursday it goes in for new brakes, oil change and a general check up. Original shop quote was over $550 for brakes, parts and labor. I ended up buying my own parts, including 7 quarts of Mobil 1 and the oil/air filters for less than $250, labor will be around $180. Saved myself over $100 What's even better, since I've spent a few grand at this shop over the past 4 years, they didn't even question it

If the SES light does reappear, my first course of action will be electrical contact cleaner, followed by further testing.