Went to MikeC4's house and he let me swap MAF's. No different, still showing a MAF freq of 0, and 0.21lbs/min, with a service light.

Thanks again to MikeC4 for allowing me to swap MAF's!

my local shop thought my MAF or O2 sensors were bad before I finally had to swap out the cat because it was running so sick...good luck getting it straight.

I imagine you've probably traced the wires to wherever they go (PCM probly, but possibly all over the place before it gets there), maybe there is a break somewhere.

Is your front O2 voltage acting normal?

Good luck resolving this issue!

Bill

Try this, install your MAF on MikeC4's car and see if it works then, then you can for sure rule it out.

Bobby

I was looking at some pics of front and rear O2 sensors. I don't think we can swap them around. One is a male connector the other is a female. I guess what I'm saying is don't get your hopes up.

Do you still have your stock pcm?

Yes, I do have my stock PCM and I was going to swap those this afternoon.
Clint sent me an email of various things to check for. I'm going to take my CAI and take my intake off to make sure the airway isn't being blocked. I may need to clean my TB.
I'm going to try a couple of options and see if I can get it cleared up.
I'm no good at tracing shorts, so if it looks like it might be a short somewhere, in the shop she goes.
All of this because I wanted to do some good by changing the O2 because I hit 100K miles, now I'm in danger of missing ACSIV, which I've already paid for.

Swap PCMs see what happens.

Good idea, but his '99 MAF sensor will not fit into my '98 because of the housing difference.

Any chance your problem could be a "lazy" or sticking IAC valve?



Rgds,
Mike

Swapped PCM's, no difference. While I had my air filter off I stuck my hand in the intake to make sure nothing was blocking the airway to the MAF and it was clear. I'm almost ready to go to the dealer and buy another freaking O2 sensor since customer service at the W-Body store seems to be a bit non-existant for me. I can't wait a month for my replacement (I'm about ready to start slamming the W-Body stores customer service ).

Bobby,

You've got PM!

hey austin, sorry I didnt see this sooner, had the exact same problem about 2 months ago... try starting it cold, it should start to idle really heavy while its cold, when its still cold and idling like crap pop your hood and unplug your front 02 sensor, the idles should clear up immediately, that is what happend with mine, I replaced the 02 sensor and havnt had a problem since.

I didnt take any maf readings but when my car was acting like this it was everything you described, bogging on launches, idling rough, and then all of a sudden when the car was warm it would just start idling fine like the problem went away. I was also getting really lean readings on my A/F gauge, check this out and let me know what you find

Did you try this out yet?

I've got a replacement O2 on the way, it should be here late this week or early next week.
All of this started when I replaced my O2 with a faulty O2. I had to rewire my old O2, which I tossed in the trash and that could have damaged it. Trash can was empty and it hit the bottom of the can. I'm sure it did do some damage. I'm kinda at a stand still until the replacement gets here.
As soon as I get the replacement, I'll update my issue.

oh ok, I thought you still had one, it should run ok without the front 02 sensor plugged in though, as long as you have the hole closed I.E. screw it in but leave it unplugged, just wondered if you could get the syptoms to go away after unplugging the 02

Number 20 fuse was blown.

how on earth did you stumble across that, is that fuse located in the fuse box under the hood?

Did that solve your problems Bobby???

I didn't stumble across it, it cost me $82 to have that fuse replaced which is a lot better than the $300-$500 I had set aside for it.

Framos, they said they couldn't get it to throw any codes after they replaced the fuse, and they told me to come pick it up. I really have a lot of faith in the shop that I go to. I think they've turned more of my business down due to the car not needing it. They've been around forever, and that's the first thing I look for when taking my car to the shop.

It would appear my problems are solved.
It kinda runs a little crappy at WOT, but this is the firast time mt OEM PCM has been in the car with the current mods I have to the car. I'll get the PCM swapped out when I get home from work tonight.
And maybe with the money I've saved, I can get that DHP PCM before ACSIV rolls around.

Also... I'm not sure which fuse box the fues was in. I did poke around the fuse box under the hood, but didn't see anything. I'm hoping it was behind the glove box, so I don't feel so much like a moron.

Glad to hear she's up and running. Now, if you could only get the DHP....

The simple stuff strikes again

Now it's sputtering when I go WOT. Not constant, kinda sporatic.
I'm going to check my wires, make sure they're all on correctly. I might have nicked the back drivers side plug enough to unseat it when I was changing my O2 last night. I'm also thinking I might have a fouled plug or two from driving it around while it was sick.
Hopefully that will take care of it.

On a bright side, I bought the DHP PCM tonight. I'm sending in my EOM PCM tomorrow. I should get it back in time for ACSIV, although if I'm still having issues I will not be racing.

Bobby,

The #20 fuse under the hood is a spare. It connects to nothing.
The fuses next to the glove box are not numbered, so I'm curious..... Which fuse was blown?

And FYI, your car should run fine with the OEM PCM. It may not run as strong, but there would be no problems while running the stock PCM if everything else was OK.

Well, crap. You are correct. I checked the ticket and it does say "replace #20 fuse". All the fuses look pretty much the same. I can't tell wich one is new.

I changed my plugs, now have NGK TR55 copper cores. The car seems to run fine, better than it has in a long time. My KR even seems to be lower, staying below 5*, mainly 3*-4* with a short spike or two up to 6*. A lot better than the 7*-8* I was getting before.

Keep your eye on the prize...

Mike (W-Body store) is pretty cool. He's sending me the PCM today, before he rcv's mine, so he can make sure I get it before ACSIV. I'm sending mine to him today, as planned, but I thought that was pretty cool of him to take an extra step since I had issues with the last product.

Yes, he is. You should see him when he's drunk. Mike K is on the left. I'm to the right in white.


Be on the lookout for the ILGPC party @ the Alamo!

Fortunately for me, my drinking days have been over for awhile. I'll still knock one back every now and then, but nothing like I used to. I won't be attending Friday nights festivities, but I will be at the track for Saturday.

I'm still getting a little bit of stuttering at WOT, near the 5600+ range. No SES light. Changing the spark plugs help clear it up a lot, but it's still lingering around. I don't guess it could be anything more than either the wires or coils could it?

what kind of studder is it, I mean basically a studder comes from a misfire in a cylinder, you konw just as well as the rest of us that a number of things could cause a misfire. Most likely it is electrical, but could also be an injector going bad or getting corroded, maybe a dirty maf, chipped piston, a head gasget that is going causing you to lose compression. You have a scanner dont you? why not take a scan of a few pulls through second and third and let us have a look see

When I changed the plugs, the back plug next to the O2 sensor, had a loose contact.
When I pulle the front middle plug (I think it was that one), it had what looked like a fair amount of a fine black powder on it. I'll get a pic later tonight and post it. I'm going to a custom car show tonight so I'm not sure when I'll get the pic, but it will be tonight.
I'm hoping this isn't the first signs of CEF, catastrophic engine failure.

ahh, it doesnt sound like it is that bad, at least your getting to the bottom of it now. Just look at it like this... worst case senario you have a chipped or cracked piston, no biggie, just replace it, this is highly unlikely though, if its a gasget that is going bad thats not a very big deal either, anything else that is wrong you can probably do yourself (dont know what kind of mechanical knowledge/tools you have avail. to you)

Don't fret my friend, it takes a lot to knock a 3800 down

Just ask 2fast4u. He was able to blow one up.

Is that carbon or metal on that plug?

Judging by the cleanliness of the ceramic, and the debris on the end of the threads......I'm guessing it's gunk picked up on the way out of the hole.

Other than the gunk, the plug looks good.

x2.

The electrode is intact and clean.

I'll put it back in the shop after ACSIV. It starts fine and even runs smooth, it's just at highway speed I have to roll easy in the throttle to pass someone. I cant just floor it or it'll start missing. I can take off hard fine, untill I get up into the higher 5K's. I actualy lost to a guy I work with. He has a 00 Mustang. I know I can beat him, I've kept up with him before I got my D/P. I know if I was running right I could have taken him.
The 100k woes.

Does your gauge show you misfires? If you see one cylinder having a problem with misfires, that would help you diagnose whether you have a bad wire, plug, or coilpack.

Have you tried swapping coil packs? I had an ACCEL coil pack go bad on me.

One more thing to consider is fuel delivery. If your not getting enough fuel at the top end it could be the FP, FPR, or Relay. The PCM doesn't read fuel pressure, so the only way your going to see it is with a seperately installed gauge.

What should these readings be?
Injector Pulse Width
Long Term Fuel Trim
Short Term Fuel Trim
Ignition Advance
Idle air Control Counts
I look at these and have no clue if they are good readings or bad ones.

I haven't swapped coil packs. Mine are oem originals and I don't have any to swap them with.
Wires are MSD, and that's the only reason I would suspect them to be at fault.
I'm thinking I might need to run some injector cleaner through the injectors.
I changed my fuel filter a couple of months ago, it should be fine.

Injector Pulse Width - Dunno

Long Term Fuel Trim - Not sure, mine varies between -5% and -20%

Short Term Fuel Trim - Should hang around 0% plus or minus while idling. Zero's out while throttling.

Ignition Advance - Mine goes to 10-11* at WOT, I'm told that's not too bad. Timing advance works with timing retard(KR) at WOT to put the spark in at the optimal time for proper combustion.

Idle air Control Counts - Dunno

I'm pretty sure none of these determine if your fuel pressure is dieing out at the top end.
The Injector PW may, but I know nothing on it.

Car went in the shop this morning for the WOT high RPM range mis-firing. I'm not getting it back today.
I told him I have a function to go to on Sat and I really would like to have it back before noon time tomorrow so I can spend some time to get it cleaned up. He said he'll see what he can do, but it's hard to promsie anything when they don't know what the problem is yet.
I hate not having my car, I'll even hate it worse if I can't take it to ACS. The wife already told me I can take her car. I told her thanks... woo hoo. That's the last thing I want to do, take a freaking Toyota Avalon to a Grand Prix/GTO meet.

Have faith Bobby!

it looks like thos are platinum plugs, is this true, if it is that may be your problem, forced induction cars do not like platinum diodes, then like either iridium or whatever the regular substance is, but I know platinum is not good for FI cars

It had NGK iridiums in it. I took those out while trying to figure out my last issue. I had a set of NGK copper cores laying around so I swapped them out. It's got the copper cores in now.
I just need to get the car sometime arounf noon today. I'll take it back and drop it off Sunday night so they'll have it on Monday morning. It rained here the other day and it's really filthy, so I need to spend a couple of hours on it to get it cleaned up, inside and out, so I can have a clean car tomorrow for ACS.

They just called.
It's ready.
It looks like it was the plug wires... good old MSD wires.
I'm off to pick her up!

Back to OEMs. You can always use wire loom like I did for your wires.

Yup, I routed the wires around the S/C and under the snout, instead of over the S/C. Now they are less noticable.
I'm just glad it's running right again.
It hasn't run right through the whole month of Jan.

Now go get 'em Bobby.