............and it has power only when accelerated hard.

I just got the truck about a month ago, it's a 2001 1500 Ram Quad Cab 4x4. Has the 5.9 cid Gas engine, has an AirRaid intake filter system, a performance chip in the computer (not Hypertech), a cat back Flowmaster exhaust & 73,000 miles. The problem is when it's cold (first start in the mornings) it idles steady, but when given a bit of gas to back out or accelerate away from the curb, it misses. Randomly, not a steady miss.

I didn't notice it until the temps dropped into the 20's - 30's. It had a surge when it was cruising so the Throttle Position Sensor was changed. That did away with the surge, now I have a miss. It does go away when the engine warms enough for the computer to take over (open/closed loop). So, I'm thinking it's not a fuel problem. It runs fine when it's warm, has adequate power, cruises well, no miss, no surging. I've cleaned out the throttle body with cleaner & tested the resistance of the plug wires. They are ok, so I don't think it's a ignition problem either.

There are no strange noises in the engine, none in the drivetrain. Just an annoying random cold miss. I'm wondering if it needs a warmer for the air intake system. Too much cold air?

Ideas would help to point me in the right direction.
Thanks.

 

My though might be that it could be due to the performance chip. The misfire is usually caused by an incorrect fuel/air ratio or incorrect ignition timing. If your performance chip modifies the ignition timing at colder temperatures, this could cause misfire. An ignition timing that has been advanced or retarded too far will cause erratic or incomplete combustion, and cold cylinder walls make it hard for the mixture to combust.

good luck

 

Thanks Kuch,

I was wondering that too. It's a Jet performance chip, so I'll try to contact them. It was already installed when I bought the truck & I'm unfamiliar with the chips. Can they just be removed or do they need another chip in it's place. Like the stock one. I haven't worked much with the computers, so I'm totally unfamiliar except for reading the trouble codes.

 

Ok, here is the answer I got from Jet:

Now I assume the chip can be removed & the harness plugged in where the chip sat. I don't have any installation instructions, but I was able to find installation instructions for a 96-99 Jeep. It said to disconnect the negative battery cable, remove the main wiring harness from the computer, plug in the chipset & plug in the harness. Then reconnect the negative battery cable. That's all there is to it. I assume the Jet chipset overrides the factory chipset - which remains in place.

So, my question remains. Do I need to get a different chipset (factory) or just unplug the Jet Performance chip & plug the harness back into the computer?

Thanks in advance.
Mark

 

The Jetchip just piggy backs on the factory computer, so you can just unplug the Jetchip and reconnect the harness.

 

I figured it out.

Twas a bad coil wire. Truck had 75000 on it, I figured it needed a tune up. Changed the cap, rotor, wires & plugs. When I was starting to change the wires, I was tracing the routing of the coil wire with gentle tugs, all of the sudden I had a bare end in my hands. The tip was pretty carboned up too. So it was missing for quite a while.

Cap, rotor & wires................. what a bit** to change. Had to trace the firing order 3 times before I got it right. Plugs changed fine. Mileage stayed the same (about 12) for the first 1000 miles, now it seems to have gotten better, to near 17 on the road. I guess it needed a tune up.

Either that or I'm getting used to all that power. See, I traded up from a 82 GMC with a 6.2 diesel (non-turboed). Talk about gutless, whew!

Thanks for the help guys. Now if I could just figure out why my torque converter clutch sets codes intermittently. Must have a loose wire on it too.

Mark