Darrell Hobson

Our venture intermittently will lose power at highway speed and die. Starting over a year ago and now almost every day. Service engine light came on only once so I had an auto part store run a scan. They said it was the mass air flow sensor which i changed. Still did it so went to dealer. The light had gone off by then. They replaced vacuum hoses and some boot. Still did it. Back in again and this time said it was erratic air flow sensor since it was an after market brand. Put on a Delphi one and still does it. Now they think transmission but we traded it in on a new Nissan. Haven't given it to the Nissan dealer yet so wanted some advice before I do to decide if I'll keep it since they only gave us $500. Chevy dealer did replace the solenoids to the transmission a year ago due to an oil leak. Car starts fine after it cools down an hour or so.

U.Nanimous

Unless someone chimes in with some "typical Venture issue" I'm going with the classic fuel pump/filter or clogged cats. At idle you don't need a lot of fuel and you aren't making a lot of exhaust, but at highway speed you need good fuel pressure and the engine needs to push a lot of air out the exhaust. You also mentioned "starts fine after it cools down an hour", does that mean it is also running hotter than normal - could be a sign of clogged cats, the hot exhaust can't leave the engine and time allows it to depressurize.

Darrell Hobson

Thanks for you input!! I don't know if its running hotter than normal. The engine temp doesn't see to be. I did notice a slight loss of power this morning when I ran to McDonalds. It's less than a mile down the street and when the car shifted it seem to slightly stumble (power). I may add some cat cleaner and try that. Wee decided not to trade it in so I have a few more days to decide to keep it or figure out what's wrong. When you first turn the key you can hear the fuel pump priming. I assume then that the fuel pump is stlll working!!

U.Nanimous

Hearing the pump is a good sign, but not a true test. Best test is checking pressure at the rail, Harbor Freight has cheap gauges for that. But before buying tools, do you know when the fuel filter was last changed?

tech2

+1. most lack of power problems are fuel related. if the fuel trim is leaning out (adding fuel) during a hard acceleration....its fuel starved.

Darrell Hobson

We got it out of the shop for the 2ne time last Thursday. Saturday through this evening I had radiator cleaner and water in it. It happened Saturday on the highway and we had it towed back to the dealer. My wife bought a Nissan Saturday night so Monday morning I picked it back up from the dealer to trade in. We decided to keep it so today I drove it off and on around the area about 12 miles with no problems. Left a restuurant at lunch and got on the highway and bam 4 miles later it did it again. Let it set for 20 minutes and made it home. Drained the flush and put antifreeze and water in and drove about 5 mies with no problems (side streets). Also put cat cleaner in and have been about 14 miles.
If the engine runs hot will that effect the air flow sensor? O'Reilly's scanned it again and got the same code for bad air flow sensor but its a new OEM one.
I'll check the fuel pump also. Fuel filter changed last May. It was doing it less but at that time some also. Worse now.

Darrell Hobson

When the service engine light came on finally O'Reilly's hand held computer said massive air flow sensor bad. Been replaced with OEM one and new vacuum hoses and still same problem loosing power only at highway speed. Have them check again when it acted up today and same code. Could fuel flow issue give a reading like that? Thanks!!!

tech2

post the code

Darrell Hobson

P0101 Mass or volume air flow A circuit range/performance
I don't understand it but that's what I was told.