95 van no power and low rough idle

[mirrlin]

1995 olds silouette van 3.8l 3800 about 160000 had had 2 extended periods of sitting when my niece came to me with the problem it acted like a clogged catilac converter maybe low feul presher
after filling the tank with gass i added a can of seafoam ( fuel system cleaner) have driven the van about 24 miles and the speed did increace from 40 to 55 and seemed to idle a little better al at once it got a loud knocking the knock did go away at about 2000 rpm is it possable for the computer to be causing preignition or am i just dreaming and in all reality its really a rod bearing

[discnik]

Make, model, and engine size would help please.

[discnik]

When is the last time this vehicle has had a tune-up ?
If the sea-foam improved the performance, check your plugs to see if they are carboning up.
If you had a rod bearing going out the knock would increase with engine rpm and would not just go away.
Sorry for the late reply had the grand kids this week end.

[mirrlin]

less than 10,000 miles ago the van would not start and was sent to a shop they were suposed to put in new plugs not sure what else

[discnik]

On a normal tune-up the shop should have done plugs, wires, cap, rotor, ( if applicable), air & fuel filter, & compression test. How is the van running now ? You said it did start picking up speed. Is it still maintaining a decent speed ? Or is it still slow to acellerate ? Loss of power and slow to pick up speed could be catalytic converters.

Just some avenues to explore.

[mirrlin]

with the pedal to the floor max speed was 55 mph and took a bit to get there
afraid to run it any more at the minute would hate to brake something the knock is loud debating on throwing in rod bearings befor i even start it agin its that bad
dont have much money bearings only about $30 i hate to do it that way
BUT GOTTA STOP THE KNOCK BEFOR I BREAK THE BLOCK