dieseling problem

[Charley Lillard]

Time to grasp at straws... Have you changed brands of gasoline ? Good gas ? Gas tank or cap vented ?

[ChevyIIMan]

Well I was on vacation durring that time I had 5 diffrent brands in it and itleast 2 diff brands while it was showing lean. It has a frsh tank of the local gas I normally use in it now, and the fuel cell is vented.

Also I changed the exhaust from dual 2.5 to single 3in pipe but had that on the car for close to 1000 miles before these problems started.

[yody]

well i didn't think it was causing anything, just that holleys like 7PSI, did you check the weights on the dist? what vacuum does the car pull at idle and what powervalve do you have?

[ChevyIIMan]

well i didn't think it was causing anything, just that holleys like 7PSI, did you check the weights on the dist? what vacuum does the car pull at idle and what powervalve do you have?

Stock powervalve and the car is pulling 5-6 @ idle, bounces a tab but I assume thats from the cam

[yody]

what 5-6 at idle???? that is less than my cam? Is that in park or drive? you probably need a 3.5 or 4.5 Powervalve, stock is probably 8.5/ or 6.5, which is probably opening and enrichening the circuit

[ChevyIIMan]

what 5-6 at idle???? that is less than my cam? Is that in park or drive? you probably need a 3.5 or 4.5 Powervalve, stock is probably 8.5/ or 6.5, which is probably opening and enrichening the circuit

Thats in park. If the Power Valve was opening and enriching the circut would the car run rich and not lean??!?! Once again same cam, same carb for years. No problems till this. Now I took thsi reading from the port on the front lower of the carb where my transmission used to hook up to, is that correct?

[yody]

yeah thats correct, I'm all out of ideas

[paul67]

you say that you used to connect the trans to carb, then maybe its pulling to much vac when warm, i had this on a range rover ticked over when cold then increased when it got warm because it drew more vac and altered the timing. just a thought
paul67

[paul67]

Ok, over here in the uk we call this preignition , popped to see and old school car chap and he says this caused , if the plug are white the carb fuel need richening up and the timing retarded as the cylinders are hot causing it to over run , classic car that used to do this on tv was the detective columbo's as it still ran when was walking away from it .
paul67

[ChevyIIMan]

yeah thats correct, I'm all out of ideas

yeah last thing I can do is pull the carb fully apart and clean all the passages out, make sure it not leaning itself out, then just try jetting it up.. Other then that I too am out of ideas.

[ChevyIIMan]

Well I completely stripped downt he carb had it hot tanked and put it back toghter.... same issues. Next im going to try a buddys carb. On the vac readings that was a problem with the guage the car pulled 13with a diff vac guage