Originally Posted by Triple X
when i put the new MAF in the Check engine light turned off. i took it for a test drive tonight and it did not die this time but the idle was still hit or miss and when i would drive and try to accelerate and increase my boost...it would stutter...i would have my foot to the floor and i would get no acceleration...but then some times it would be fine...until it sputters again...and at stop signs or lights...my idle would drop and the car would be vary close to dieing. it would idle just under 1000 rpm and out of no ware it would correct it self for a little wile and put it at about 1200rpm...then go back down again...when it is vary close to dieing the car shakes..not wildly but enough to feel it....
can anybody figure this out?
I've been trying to watch from the side and let Willwren follow through on his plan. But I can get you started on a suspect area.
I'm thinking you may have multiple problems. As I learned from Willwren (gotta give him the credit) crapping out under acceleration/load is often ignition related. And your poor idle may be another indicator of this. Here is a quick and easy check to see if you have one or more cylinders that are not up to par in the ignition department.
- 1. Start motor and let it calm down a little (should only take a few seconds to a min. or so)
2. Unplug the IAC valve (near the TPS on the throttle body and is a black cylinder shaped item)... not to exceed 2 min. at a time.
3. Pull the plug wires off at the coils one at a time while listening for a change in idle. The miss will either get worse or stay the same. Of course, when the miss does NOT get worse with a wire off, that is one of your bad plugs, wires or coils. I'm a chicken, so I like to use rubber handled pliers and rubber gloves. It will still give you a little tickle when the wire is put back on.
OR, an option would be to shut it off in between, put the wire back on and then restart to check the next one and so on. It needs to be running when you pull one though, it will be more apparent if you get a change or not. Plus the "tickle" doesn't come when you remove the wire, it'* when you put it back on.
4. When you pull a wire off a GOOD coil output, it is normal for arcing back to the coil body. So, if it does NOT arc, suspect an issue with that coil output. It can be bad on one output of the two and the other to work okay.
If you suspect a coil, you can do a resistance measurement across the 2 output terminals. I believe it would be around 15k ohms on a good one; or infinity (open) on a zapped one.
If the above check exposes a problem, items failing that would cause a discernible MISS would be in this order
1. Plug Wires
3. Plugs (for one to actually stop firing it has to be REAL bad and is often a result of something else... not to say they don't need to be replaced regularly for good performance).
Let us know what you find on this check and we can go from there... or Willwren can ...
1993 Red SSE - Bone-Stock except for High Perf. Power Antenna-Original Owner. Less than 130K - Love of my Wife
'05 Magnum R/T Hemi - Bunches of classic VW Beetles... and one "not quite stock."