97 2.5 dohc misfire 1&3

97 Outback 2.5 dohc misfiring on 1 & 3 at idle. Around 50k miles on the engine. Runs great on the road or highway. Idles really rough and codes misfires on 1 & 3 which we know are on the same side of the engine. Compression checks out fine on both 1 & 3. Changed the coil pack although it was a used one. New plugs and wires. Have checked for vacuum leaks using the old carb cleaner trick of spraying around vacuum connections and hoses to detect a leak. Haven?t found any. It idles so bad sometimes it starts knocking but if you get in and take off it stops and funs fine till you stop at the next light. No evidence of gas or coolant in the oil or vise-versa. I did take the timing cover off and checked to see the cam gears were still lined up. They are. ANY other suggestions would be great. Thanks.
Reply to
dsoundman
Loading thread data ...

Was the compression check done with both spark plugs out at the same time?

You might tee in a vacuum gauge to make sure the needle is steady while it's missing. If it isn't then you have valve train problems.

I suspect though that you have leaking injectors. Are the 1 & 3 spark plugs a darker color than 2 & 4? Hook up a fuel pressure tester, cycle the key to build pressure, then watch the gauge to make sure it holds pressure.

Reply to
Dave

vacuum gauge does fall around three lbs (from 18 to 15) when missing occurs. fuel pressure is steady. gauge only reads up to ten lbs. and pressure is steady there after waiting several minuets. still steady when engine is running. sparl plugs look similar. had both spark plugs out when checking commpression. do you think i have valve train problems?

"Dave" wrote: > "dsoundman" wrote in message > news:1206219 snipped-for-privacy@autoboardz.com... > > 97 Outback 2.5 dohc misfiring on 1 & 3 at idle. Around 50k > miles on > > the engine. Runs great on the road or highway. Idles really > rough and > > codes misfires on 1 & 3 which we know are on the same side > of the > > engine. > > Compression checks out fine on both 1 & 3. Changed the coil > pack > > although it was a used one. New plugs and wires. Have > checked for > > vacuum leaks using the old carb cleaner trick of spraying > around > > vacuum connections and hoses to detect a leak. Haven't found > any. It > > idles so bad sometimes it starts knocking but if you get in > and take > > off it stops and funs fine till you stop at the next light. > No > > evidence of gas or coolant in the oil or vise-versa. I did > take the > > timing cover off and checked to see the cam gears were still > lined up. > > They are. ANY other suggestions would be great. Thanks. > > Was the compression check done with both spark plugs out at > the same time? > > You might tee in a vacuum gauge to make sure the needle is > steady while it's > missing. If it isn't then you have valve train problems. > > I suspect though that you have leaking injectors. Are the 1 & > 3 spark plugs > a darker color than 2 & 4? Hook up a fuel pressure tester, > cycle the key to > build pressure, then watch the gauge to make sure it holds > pressure.

Reply to
dsoundman

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.