Car finally runs! Not out of the woods yet., Rough idle problem Options

[scoobykvn]

So I got my 1970 1.7 still injected finally ready to drive. It starts right up with and runs fine, for about 20 - 30 seconds, then it starts to idle rough. The idle will drop to almost 0 then surge to about 1500 - 2000rpm. If I slowly roll onto the throttle it revs up, but if I quickly press the throttle it stumbles and almost dies then revs up. I am going to get a vacuum gauge soon and check for leaks using the method in Tech Tips 700. Anybody have any ideas of what to look for? Could it be something other than a vacuum leak?. I have done a valve adjustment, replaced points, rotor, cap, plugs, injector seals. Still have not checked timing or dwell. I will also double check the MPS.

[914_teener]

You have the same problem my car had. I had the same symptoms yours has now. I bought a 1.7 that had been sitting a while. I replaced all the vacum hoses just for good measure..... still did the same thing. After further inspection I found that the elbow that goes from the air cleaner to the trottle body was cracked in several places and just as you had found, and I used some Black RTV to seal it. The car ran ALOT better after that but still hunted like yours does. After awhile it got worse and I started to look other places. I found it. The intake boots were leaking pretty badly. So I ordered some and replaced the injector seals while I was there. Car runs great now. Some info about the 1.7 that I was told by George Hussey... that the stock intake runner boots for the 1.7 are slightly smaller than the 1.8, and they don't make the boots for the 1.7 anymore, so...... you should put clamps on the boots. I didn't like the idea cause it doesn't look like factory but did it anyway. Don't know if anybody on the board has ever heard this though.

For the miss... that could be alot of things. My quess would be electrical.. spark plug wire or possibly an injector wire... just a blind quess.