A problem that only shows up at normal temp, warmed up

**pinky** · 12-28-2013

I start my 99 gtp (completely stock other then cat' has been cut off)
Runs fine, pulls decent, Only making 1/2 boost according to digial gauge, but feeling that's the intake manifold gaskets. now everything runs find till it's warmed up if i have to drive in stop light traffic it starts to stumble,backfire, and die and sounds like it's missing bad.

Now if I shut it off and wait 5 mins runs find no problem till it happens again. now if I get on the highway and drive 60+ it never does it.

any ideas (owner said it had a cloged cat so they cut it off)

**Twizted 1** · 12-28-2013

1/2 boost sounds like the BBV took a dump on you. (The electronic solenoid below the vacuum canister on the side of your SC.). Or a vacuum line is cracked or come unplugged.
As far as the running issues, I would start simple and clean the MAF. make SURE it is completely dry before you reinstall.

Sent from Not so smart smartphone

**Scottydoggs** · 12-29-2013

so being it has no cat the cel is on already right? so get it scanned see what codes its got.

this could be as simple as a it needs a tune up. if its random misfires

**indygrandprix** · 12-29-2013

Possibly stuck open EGR valve

**pinky** · 12-29-2013

No codes.: /

**Twizted 1** · 12-29-2013

Check the vacuum line, the BBV and clean the MAF.

Sent from Not so smart smartphone

**pinky** · 12-29-2013

Swapped coil packs, and ignition module, ignition module was atved to the mount -__-
Now I make no boost on the gauge, pulls good but still gets warm and starts missing like holy ****

Swapping maf for a good one

**Scottydoggs** · 12-29-2013

if its misfiring that bad there should be a code for it. maybe stored so the lights not on. id get it re scanned.

what the word on that tune up? ever do one?

**pinky** · 12-29-2013

Nothing. Maf don' help, tune up still no better runs smoother until its warm

**Scottydoggs** · 12-29-2013

have you done one since you owned the car? a tune up that is? whats the miles?

old plugs and wires can do exactly what your describing.

**pinky** · 12-29-2013

Just today

**Scottydoggs** · 12-29-2013

what plugs did you put in?

**pinky** · 12-29-2013

Al605

**Scottydoggs** · 12-29-2013

are those the double platinum plugs? if so toss them and go get some iridium plugs. these cars dont like the plats one bit.

**pinky** · 12-29-2013

I was able to pull as code now. Boost solenoid, low maf signal, and 3x reference circuit

The Wire harness is a bit rough. For the crank,cam,and ign

**pinky** · 12-29-2013

No they are what the write up on how to safely mod your 3800sc

**Scottydoggs** · 12-29-2013

the maf, check the wires to it, if you see any cracks in the wires near the plug or down the wire, it can cause the low circuit code.

new pig tails are cheap. around 10 bucks.

**m17davis** · 12-29-2013

I've been running at about 4.5 psi since I bought my car about 6 years ago. About a week ago I found out I was at about half boost I should be at. 10 minutes ago I replaced the BBV solenoid with the one on my extra gen3. Now im at 10 psi of boost.

**pinky** · 12-29-2013

Swaped out the wires nothing, runs good then goes full retard 15-20mins later. Wait 5-10 mins runs fine for another 15-20mins before going full retard again

**pinky** · 12-30-2013

Update, when it starts acting up the bbv opens and closes over and over and over, smells pig rich,and sounds like a bad miss on 2 or more cyls

I'll try to get a video of it tonight