Jerking at cruising speed.

[teamo2t]

Hey all. This weekend my car wouldn't start up. Checked for spark and the coil pack was firing. Changed it with a spare I had laying around. Got spark but still wouldn't start. Turned my attention to fuel. When I disconnected the fuel line from the rail I did not have any pressure built up. I primed the system and started to get some fuel out. When I reconnected the line it started.

Here is my problem. When cruising at 2k and slight throttle the car jerks like a bucking bronco! Wtf? Not sure where to go from hear. Dsmlink is not showing knock. Any thoughts?

Side note the car was sitting for about a total of 2 years. Sat for 6 months at a time.

 

[jb2zero0six5]

Fuel system got junk in it? Try changing the filter, after running a lot of the old gas out. Then get a fresh tank of premo, and injector cleaner. I'm sure they gummed up, too.

 

[hypergenesis]

Fuel system got junk in it? Try changing the filter, after running a lot of the old gas out. Then get a fresh tank of premo, and injector cleaner. I'm sure they gummed up, too.

Forget injector cleaner . Go use some seafoam if its been sitting for that long you need to seafoam a good bit all the way through to clean out your whole system

Armin

 

[teamo2t]

The thing that confuses me is the issue seems to be mostly between 2-3k rpm and with light throttle. If I punch it it accelerates just fine. I put some injector cleaner in and about gallons of premium in just now. I'll let you know if that clears things up a bit.

 

[talonDSMerr]

Are you getting any CELs? My car acted the same way when I bought it several years ago and it turns out the TPS was not reading at a particular point within its range, and whenever I pressed the throttle to that point, the ECU would have no idea what position the throttle plate was at and led to a lot of jerking and confusion.

 

[jb2zero0six5]

Ahh yes, seafoam.

I sure it just needs to be driven, sensors need the cobbwebs cleaned out. Had a Chevy pick-up that sat, squirrel thought it would be great place to hide his nuts in the air filter box!

Do you have anyway to check for fuel pressure? Your going to want to see about 43 psi, with-out the vacuum line hooked up.

 

[teamo2t]

No cel but a friend of mine said he had the sane problem with his tps. Pardon my ignorance but can I check the tps with dsmlink?

 

[teamo2t]

I don't have a way of measuring fuel pressure.

 

[teamo2t]

Resolved! Ran with dsmlink showing Throttle pos. It was going crazy!!! Need a new sensor. Thanks everyone!!!