Hesitation problem
Moderators: Helpinators, Moderators
Hesitation problem
I've had this car for about a year but I've had it parked for the whole time because it wont run right. It holds steady at 9psi but the car has a horrible miss. I've done plugs, wires, filter, ecu reset, changed the maf, relocated the knock sensor. I'm at the end of my ropes here. The car has 107000 on the clock so I dont think it's a dead cylinder. The only thing I can figure is the exhaust leak is causing problems. Anyone experience this? It's a 91ss automatic.
-
biglittledog
- In Neutral
- Posts: 12
- Joined: Sat Jun 02, 2007 5:44 am
- Location: Boulder, Colorado
Hi. We both have threads on hesitation and nobody is answering either of them so I thought I'd throw in my 2 bits even though I don't have a turbo.
If you can make the miss happen, especially if you can do it by revving the engine while the car isn't moving I would hook up a vacuum gauge off the manifold with a tee connector. You can learn a huge amount by watching the needle movement at idle and when the throttle is opened. I got mine from Harbor Freight Tools for 8 bucks on sale but you could grab one from Ebay real cheap.
I've gone a little old school lately...back to the timing light and vacuum guage, checking plug condition etc because the ECU can fool you by throwing codes caused by something else or not throwing codes at all.
I just took out my knock sensor and its totally f***ed and the car never threw a code at all but was running like crap. The way I figured it out was by hooking up a timing light and putting a small piece of masking tape on the pulley and watching the timing change while I revved the engine. In my case, it was retarding the timing the full 20 degrees so the engine wouldn't accelerate at all. A vacuum gauge will tell you if it's valves, rings, dead cylinder etc. without replacing stuff for $$$. It might be a good way to start. Good Luck!
For starters:
http://www.autospeed.com/cms/A_2393/article.html
If you can make the miss happen, especially if you can do it by revving the engine while the car isn't moving I would hook up a vacuum gauge off the manifold with a tee connector. You can learn a huge amount by watching the needle movement at idle and when the throttle is opened. I got mine from Harbor Freight Tools for 8 bucks on sale but you could grab one from Ebay real cheap.
I've gone a little old school lately...back to the timing light and vacuum guage, checking plug condition etc because the ECU can fool you by throwing codes caused by something else or not throwing codes at all.
I just took out my knock sensor and its totally f***ed and the car never threw a code at all but was running like crap. The way I figured it out was by hooking up a timing light and putting a small piece of masking tape on the pulley and watching the timing change while I revved the engine. In my case, it was retarding the timing the full 20 degrees so the engine wouldn't accelerate at all. A vacuum gauge will tell you if it's valves, rings, dead cylinder etc. without replacing stuff for $$$. It might be a good way to start. Good Luck!
For starters:
http://www.autospeed.com/cms/A_2393/article.html
94 Legacy Alpine AT NA
00 Forester
91 325i convertible 5spd
00 Forester
91 325i convertible 5spd
-
biglittledog
- In Neutral
- Posts: 12
- Joined: Sat Jun 02, 2007 5:44 am
- Location: Boulder, Colorado
That sounds high but I don't know the turbo. My N/A Legacy pulls about 11 at idle. More importantly, is the needle on the vacuum gauge steady? Does it climb and then drop when you rev the engine?
Also, you can try putting a piece of masking tape on the pulley. Start the car and watch with a timing light while you rev the engine. On mine the timing was retarding a huge amount which led me to the knock sensor. I'm not sure but I think it should dip a little (move clockwise) and then quickly advance for the increased engine speed (move counter-clockwise well past the original position at idle).
Good Luck!
Also, you can try putting a piece of masking tape on the pulley. Start the car and watch with a timing light while you rev the engine. On mine the timing was retarding a huge amount which led me to the knock sensor. I'm not sure but I think it should dip a little (move clockwise) and then quickly advance for the increased engine speed (move counter-clockwise well past the original position at idle).
Good Luck!
94 Legacy Alpine AT NA
00 Forester
91 325i convertible 5spd
00 Forester
91 325i convertible 5spd