Wierd Timing Question

[rowdie- stang]

I just installed a dss 347 with a msd distributor My question is it idles very high (2500 rpm) when I set the timing at 10 btdc, when I adjust it to 10 atdc it idles fine it also overheats very quickly. oculd this be a vacuum leak around the intake or something.....I have to pull the top end apart anyways to retorq everything. Has anyone had a problem of this sort....

 

[rowdie- stang]

by the way I have a 70 mm mac throttle body, and also all of my idle adjustments are closed (air adjustment plate behind iac, throttle screw is all the way out)

 

[HISSIN50]

i like the vac leak idea. also make sure your balancer has not slipped at all (giving you false reference points for timing it).

good luck.

 

[70lightning]

is the dizzy 180 out?

 

[rowdie- stang]

I put a knew romac balancer on it....how would it slip with the key in it anyway?

 

[rowdie- stang]

what the crap is a dizzy 180.....

 

[twolo4u2c2]

I think he is saying is the distributer 180* out of adjustment. Its just quicker the other way.

 

[seijirou]

Get a can of brake cleaner or gum cutter and start spraying around your intake and vaccume hoses. If you have a vaccume leak, it'll suck in the stuff and the rev's will increase briefly.
A high TPS setting can cause a fast idle as well, so check it's voltage.

 

[z2o_what]

is the dizzy 180 out?

any time that i've has the dist. 180 out the car wont start, it backfires through the intake

 

[rowdie- stang]

I set the "dizzy" at #1 tdc

 

[rowdie- stang]

I think I am going to tear the top end down tomorrow and retorq everything and then see what happens

 

[seijirou]

#1 reaches TDC at two different points in the 4 stroke cycle. One is at the top of the compression stroke, and this is the TDC that you are looking for when setting ignition timing.
The other is at the top of the exhaust stroke. If your sparking happens here, that's when your dizzy is 180* out.
However, she isn't going to run like this, so if it runs at all, you don't have this problem.

 

[BeerElf]

If you're using the Ford Idle Air adjustment plate between the IAC and the throttlebody, the two screws (2.5mm allen screws) need to be screwed all the in to be closed. If they are all the way out it's wide open and you're letting more air through at idle.

 

[rowdie- stang]

they are all the way in....thanks anyways