E4ME tuning help

[Wajulia]

I know what you mean about forgetting stuff -- keep trying!! I sure could use a hint.

I did not do the bushings -- but spraying starter fluid by the base of the carb has no effect -- do you think that it indicate a leak through the bushings? It is winter soon -- I will tear the carb down and go through it all again

 

[GerryLP]

It is steady, But it does change if the engine is revved. I will check the PCV valve.


If it where running open loop, would it eventually kick out a code?

It probably would, but to find out, you'll have to clear the codes first before performing the troubleshooting, so that you can tell that it was set.

Also, if while idling and while hooked up to the dwell Gage you place your hand over the air horn, and if the dwell needle begins to hunt, then that is confirming that there is an air/vacuum leak somewhere, and that the carburetor cannot keep up with it.

But just to be clear, the book says that the needle should be somewhere between 20 and 50 degrees on the 6 cylinder scale for the system to be working. So the concern here is not why you are getting only 27 degrees on dwell scale, but more importantly, why is it not moving the needle of the Gage (should not be steady. It should hunt).

GerryLP:cool

 

[Peer81]

A side note. I don't know what size dwell meter you have. I have a small hand held dwell meter and it is very jumpy, it reacts almost instand on revving the engine etc etc. But a few months ago I checked Cor's dwell meter to see if it was working. Between this and mine was a 3 degrees difference (not that big I think) but the biggest difference is that he has a big dwell meter (box size) with a big needle. It's like the needle is damped or something because when looking I couldn't see it hunting. When I looked better I could see it very very minimal hunting but not much. So nothing wrong with his dwell meter but there is a difference. Just a thought

Greetings Peter

 

[Wajulia]

Trying to figure out two things, why doesnt it change with an input from the idle air bleed screw and why does it go to small numbers after a few minutes.

I guess I will try to fix the idle issue -- my engineering training says, fix anything that you know is wrong -- you never know how it is masking the real problems.

 

[GerryLP]

Trying to figure out two things, why doesnt it change with an input from the idle air bleed screw and why does it go to small numbers after a few minutes.

I guess I will try to fix the idle issue -- my engineering training says, fix anything that you know is wrong -- you never know how it is masking the real problems.

Do you have the "J" looking tool (I forget the number), that is use to set the air valve to the ball park setting? Sometimes, if one goes too far in either direction, it is hard to tell if one is
adjusting towards or away the sweet spot. The tool is good to get back to square one with the
System.

I have had the need to let the Vette idle for 20 or 25 minutes to make sure tge engine is warm.

GerryLP:cool

 

[RC81]

Mine was doing the same thing - dwell would drop then stay down. I set the idle mixture screws to the factory setting - 3 1/3 turns out from seated - then using the J tool set the idle air bleed valve to the factory setting. It still wouldnt change but by slowly adjusting both I was able to get a varying dwell in the 30 degree range. Manual says to turn the screws out an additional turn if you need to. Remember the car has to be warm - it cools fast and seems to go into open loop easily and when you make an adjustment give it time to react. Make sure your TPS voltage at idle is correct at .56 volts and when you do your dwell test the manual says to put it in drive - make sure someone is in the car with foot on the brake! I did all this and was able to get mine set but it does take some time and playing around with the both the air bleed and mixture screws. Good luck!