Ok, non-Ford...but just checking to see what you guys think. On a Chevy Cavalier - 1995 - 2.2 liter 4 cylinder...

Engine misses badly only on occasion, not constantly. Under a load (accelerating) and sometimes at idle. Dealer said they can't find anything wrong, but I just now saw the vacum hose that goes to or from the charcoal canister hanging loose because the rubber hose that connects it was split open from old age I guess. So do you think this is the cause? To me it makes sense because the canister only gets purged or whatever only once in awhile...so my thinking is when this happens, that's when I have the sputtering engine trouble. Make sense to you all???

 

You can plug that off if you want to it is non fundamental to anything, but I dont think that is the problem....

Does it have any codes? Have you noticed a decrease in fuel milage? How long has it been acting up or atleast when you first realized it? Do all of the spark plugs look alright? Does it rattle or spark knock when it is missing?

 

Check engine light is NOT on and I don't have scanner old enough to read OBD 1 codes. Dealer claims they didn't have one either Plugs are fine and wires are new. It's been like this for maybe 2 weeks or so. What it sounds like it's doing is 'spitting' or backfiring lightly into the air filer box when it happens....or at least that's how it sounds to me. no knocking or rattles....just power loss and that intake spitting/backfiring sound.

 

I think they have a timing belt..sounds like that might be the culprit.. Back fires are out of time firing, belts ussally have a life span of 125,000 mile on average though some go longer. Has it ever been changed? I'm just guessing, site unseen, but you will have to tear in to it to check it...Hopefully someone else might have a cheaper test or idea...

 

This engine has a timing chain, no belt...

 

I am more familiar with chains....Don't know much about the belts except hear say...Still could be the culprit... First.....

Does it have a centrifucal distributer too?

 

Has no distributor...

 

Could be the result of a worn camshaft as well

 

Dealer already suggested changing the wires and coil packs - and I have those new items standing by if needed. I stopped in my tracks though when I saw the bad vacum hose. So I'm replacing that first. If the trouble continues I'll change the wires and coils. I was just wondering if anyone knew for sure if this vacum leaks would cause the problem I have.

And yes the coil packs ARE on the back of the engine and it's VERY difficult to get to them.

 

If the vacuum hose is pulling in too much air the car will probably have a high idle as well....a miss could come from an overly lean condition caused by the extra air being sucked in. However I have only seen this when like a brake booster vacuum line came off... something that draws a lot of air

 

Has anyone checked to see if there is any water in the gas?? That would cause the engine to run rough and idle all over the place. Check the plugs could be a bad spark plug? Just try the process of emlimation.

 

I was afraid of that...Cant check timing using TDC as easy...LOL

I agree with Arctic Cat F7 start with the simpliest & cheapest and work in..Pull the plugs and inspect for discolorazations, damage, etc. Inspect SP wires for wears, cracks or if one is against something that might ground it out occassionally.

Check and clean connections to Power distributin box under the hood... Odd as that sounds I have had those connections do everything from kill an engine, to stalls, to bucking and misses etc...

 

Fuel hasn't been checked really. Plugs and wires have along with anything else obvious - by the dealer. They suggested replacing the wires and coil packs. I'm doing that this weekend since the vacum leak wasn't the problem (corrected that yesterday).

 

make sure the right spark plugs are in. I could be a bad spark plug wire. Electronics are the worst to correct cause it could be a so many things. I know cause I'm a certified Mercury Marine and Polaris tech. I always start with the plugs and work my way out to the points to the distributor and so one. If it's not electrical check the fuel system start with the tank. Is the fuel sending unit sized in the tank? is there a crackin the fuel line maybe theres air getting in?? Other things to check could be a cracked manifold? Or even worse you burnt a piston ring and lost compression this would cause for poor idling and running. It would sound like ch!t.

Timing could be off? Can you get a hold of a timimg light?? Go buy a service manual for your car this a huge help. It tells you the factory spec's.

 

Also have the CDI box checked. That could also be the problem!!
CDI = Controlled Displacment Ignition