2000 GTP bogs on hard accelleration

[tblake]

Noticed it tonight, floor it at about 55mph and it bogs down for a second then goes, and bogs, it will buck like that for a few seconds then accellerate. Drives just fine outherwise. I hope its not a tcc issue. Tomorrow I'll try and check for stored or pending DTC's, and check out the TPS for a good sweep, as well as watch the MAF frequency.

Anything else to check? New delco pump in december, new plugs delco last month. The wires I replaced when I got it at 70k or so. So they have about 100k on them. So they may be time, although when I put plugs in it, they seemed ok. Fuel filter replaced when I put the pump in.

It boosts just fine, and reaches full boost, and can reach full boost by accellerating from a stand still. Just does the bog thing from a steady 55-60mph floor.

Forgot to add its a 2000 with approx 170,000mi. Problem just cropped up as far as I can see although I dont floor it too often. Just when I do I need power there.

[richtazz]

it does sound like a TCC unlock-delay issue, let us know what you find when you scan it.

[TDWPgtp]

can you tell if its misfiring? if so, i could (and hopefully is) something as simple as your wires..

[tblake]

I drove to work today and accellerated to 55 and held it there crusing, rpm's were about 1700 in OD. I stepped on the brake about 5 times briefly with my left foot and each time the TCC disenguaged like it should, RPM's went up. So as far as I can tell the TCC should be working fine.

Feels like a large missfire or a fuel deliver problem to me. I might ohm check the coils as one slightly bad coil could cause a large miss under load but have enough spark voltage to jump the gap at light accelleration.

I wonder if its KR....

[rickisrad]

Doubt it is knock retard, I cant remember the mods you have though. check catalytic converter flow. sounds like a miss, maybe injectors. I use the old fashion way to check the coils. here is a link on you tube for the way i test them. they should all have about the same arc.

[olopezm]

Wish I could be of more help but I guess this time I can't LOL.

I was thinking since you just noticed it and didn't seem to happen before AND you recently replaced it, could it be by chance the fuel pump resistor?, just an idea...

Oscar.

[tblake]

Rick, missing the link to youtube?. HAHA

Oscar, valid thought but the resistor is used for cruising only. Under hard hard accelleration, the PCM commands the fuel pump speed realy to bypass the resistor altoegher.

BTW, the wiring diagrams were perfect. Everything I needed, thank you!!!!!!

[rickisrad]

here it is.... :O http://www.youtube.com/watch?v=eNx9YDodgE0

[olopezm]

Originally Posted by tblake

Oscar, valid thought but the resistor is used for cruising only. Under hard hard accelleration, the PCM commands the fuel pump speed realy to bypass the resistor altoegher.

BTW, the wiring diagrams were perfect. Everything I needed, thank you!!!!!!

Somehow that's what I was thinking last night. It's obvious that a resistor will decrease the voltage instead of increasing it! Basic ohm's law. Looks like I had a serious case of brain freeze LOL.

I'm glad the diagrams worked, whenever you need anything else you know what to do!

Oscar.

[tblake]

New plug wires did the trick. The old ones had 100k on them and 4 changes of plugs, so the boots were probably carbon tracking on hard accelleration. The old gir accellerates as she should now. Not bad for a 10+ yr old car with 170k on it.

[00GTP4ME]

Glad you got it figured out Tim. I had the same issue only not as severe. A little chunk of the wire sleeve got ripped off somehow exposing the wire. New wires fixed it.