help with diagnosis, popping through exhaust Options

[joeav8tor]

Hi guys,
I go back and forth with wanting to sell my 73 Phoenix Red 914 2.0 with stock fuel injection, but the weather in the Northeast has been nice and I have been driving it, and want to keep it but its driving me crazy...I'm having a problem that maybe you could help me with...I bought the car and took the engine out for new fuel lines, vacuum lines, pushrod tube seals, shifter seals, oil cooler...the works....I recently painted the car (with the engine in) only the exterior was painted...after 1.5 years of paint and body work....there is a popping through my exhaust and the idle is not steady, sometimes 1000, sometimes 500, sometimes 900-1000...the popping is new, but the idle was always a problem...yesterday I replaced the points, set the dwell and the timing...still popping through the exhaust and the idle is still acting up, when I turn the distributor and the RPM increases...the popping goes away and my idle is higher, but the car is not timed correctly (using a timing light and the Haynes manual, process was done correctly) when the car is timed correctly...the idle adjustment screw when turned and sucking a lot of air will only get the idle to around 1100 and I have to adjust the D Jet control unit to try to get the idle from bouncing, but its not running right...I did reconnect the tranny grounding strap when I put the engine back in...I never replaced the PCV valve or adjusted the throttle switch...I want to keep the original fuel injection in the car if I could...but I could see why guys want to tear this stuff out...it has been driving me crazy for years.
thanks (IMG:style_emoticons/default/flag.gif)
Joe

[jmill]

That will give you a vacuum leak but it wouldn't affect total advance. I was hoping that you didn't disconnect the vacuum line. Total advance is initial advance plus vacuum and/or mechanical advance. If you left the line on you wouldn't have enough total advance. That would explain why the car runs better when you advance the timing. Check that your vacuum advance diaphragm doesn't leak. Put the line on the distributor and suck on the end of the line. You should see the vacuum advance move and you should only be able to suck a little bit. If you can just keep sucking and nothing moves your vacuum line or the diaphragm is bad. Check that your mechanical advance moves freely too. I think that the FI dizzies have both mechanical and vacuum advance.

If it's an FI problem I'm out. I'm a carb guy. Just swagging it, if it's not a timing issue, I'd say you have a vacuum leak. At higher RPM you wont notice a small one. At idle it would cause the problems you described.