Misfire????

[asghert]

I posted one last week about a possible misfire at around 50 mph. I read through some of the old paperwork on the car and it seemed like when he reported a problem with running rough i saw a few waste gate valve adjustments. Does this sound right? The engine bounces a bit at idle, but a lot of people say to expect it with a GN. Also the turbo seems to be under vacuum at speed when i feel the miss. I did a tune up and replaced the EGR solenoid and no changes. Any suggestions?

Could timing be an issue? My distributor is obviously electronic, but I've heard of guys adjusting theres with a computer..?? Any reason to check this out?

Thanks

 

[TurboBuRick]

Do you have a scantool?

What spark plugs are in the car?

How old is ignition (coil pack/module)? AcDelco?

 

[asghert]

We hooked it up to a new Snap-On tester and it only returned EGR Solenoid.

Would a chip cause a timing change?

The new plugs are delco.

Not sure about the ignition coil and distributor. I do have all the old service paperwork from the first owner and nothing reflects it.

Don't think vacuum lines have ever been replaced.

SO MANY VARIABLES. I HATE LOOKING FOR GHOSTS.

 

[SHADOWII]

What year .....

vehicle are you running? the last year of the distributors were the 83's and they were electronically controlled, not vacuum operated. Are you running a chip?If so, the egr is normally eliminated.
In my experiences w/the back-firing, it would be the module going out. check forst the cap for corrosion on the inside, tracking, cracks. check for tracking on the outside maybe from leaking plug wires, etc.
Does the car have high mileage?
The egr will cause the engine to rock if it is not sealing properly.

 

[asghert]

Ignition Module? Eliminate egr? Wish I would've known that last week. Remove the solenoid and valve and plug the vacuum line? Had a suggestion to buy a scanmaster. Might do that.

 

[Westriver87]

If you got a misfire underload and while at idle, the first place I would start would be the coil pack and ignition module. Ohm out your coil pack and see what you come up with.

 

[tcgn]

Possible bad plug wires. How old are your plug wires?

 

[asghert]

New plugs and wires oem.

Engine bounces at idle. Not sure it's a misfire.

how do i ohm the coil pack?(to ground) across terminals?

 

[pajo]

@

read up partner you are going to need it ..Quick Reference Page For the '86/'87 Turbo Regals and '89 Turbo T/A

 

[tcgn]

Do you have a vacuum gauge? if so, get a reading. A normal vacuum reading with needle should be steady @ 17 to 18 inHg in neutral or park gear. Just to rule out engine mechanical problems.

 

[asghert]

13 inhg

 

[tcgn]

13 inHg is pretty low. If the needle is steady @13 inHg and not jumping around go check for any intake vacuum leaks including PCV valve, turbo hose connections from turbo to T/B. Won't hurt to perform a compression test on all cylinders and check the running conditions of the spark plugs.

 

[asghert]

Scratch that. When the engine is warm I'm at 16.