'94 voyager, 3.3L- Randomly the van is hard to start. It will try, but it's acting like it is not getting any fuel and will sometimes stumble while driving. If you pump the throttle, it will run and start acting correctly.
fuel pressure at start up and running is 40-42psi. (new fuel filter)
Snap-on scanner shows no codes. When running, the IAC, O2, TPS, MAP, and EGR are all within spec.
TB has been taken off and cleaned up as well as the intake. (all new gaskets)
Any ideas?
CBP ENGINEER
12-12-2005, 10:36 AM
Check your spark plugs. I just changed the plugs on my neighbor's 94 Caravan with the 3.3L. The van had 140K miles and the original plugs. Needless to say there wasn't much left of the plugs. Symptoms were the same as you are describing. The rear plugs are difficult to change, so he didn't bother replacing them until the van started running real bad.
The front plugs are easy to get to, so pull one out and check it. If it is bad, they will all need to be replaced. To change the rear plugs, you have to reach up through the "tunnel" where the rear exhaust pipes come down. You need long skinny arms to reach the plugs, but it is possible to get them out. The hardest part is getting the plug wires off. I found that a pair of locking needle-nose pliers works well to twist the plug wire so you can break it loose.
dirk0
12-12-2005, 10:38 AM
forgot to mention that a full tune was done 3 months ago. plugs/wires/pcv/all filters. Problem MIGHT be the catalytic converter. It started backfiring through the intake and seems to have less power. I'm going to do a pressure check today.
CBP ENGINEER
12-12-2005, 10:57 AM
My next guess would have been camshaft position sensor. I had one go bad on my 97 Caravan, but that showed up in a code. CAT is a good idea, since it is a mechanical part that won't show up in a code scan. By the way, how do you do a pressure check?
How about misfires? If you have a scanner, it should tell you if you had a misfire in any one of the cylinders. If this doesn't come up, then everything should be working correctly up to the point of air/fuel ignition. This does lead you towards suspecting that the CAT could be plugged.
dirk0
12-12-2005, 12:36 PM
here is where it gets interesting. As of yesterday morning, my fuel pressure was 40psi or so. As of right now, it's 20 or so. And it has a full tank. Once it starts, I can drive it at 70mph or so as long as it doesn't down shift. There are no codes from the scanner. Fuel filter was changed out not too long ago, so I'm going to pull the pressure regulator and pump to see if it's clogged. While I'm there, I'll test voltage. Otherwise, looks like it's the pump.
Great day! :(
P.S. when I was checking fuel flow, more air than fuel was coming out. don't understand that one. There are no fuel leaks that I can see.
dirk0
12-24-2005, 01:27 PM
update:
New fuel pump is installed. I am still getting low fuel pressure. (under 30 psi). I checked the voltage to the pump and everything is fine. ideas?
