Timing jump!

[KenneBell]

88 Turbocoupe motor in my 92 stang and it started pinging when I get on it now. I thought at first it was bad gas, I decided to check my timing. Took the spout out and it is at 10 degrees btdc, I then retarded it with spout out to 7. I then put the spout back in and started the car up, the timing showed about 16 degrees, I then reved the engine and the timing mark shot up to thirty and stayed at thirty idling very rough, then I reved a couple times more and the timing went back to around 16. Any ideas?

 

[mg man]

Maybe wrong again I read in 85 ford manual about the vane in the distributor generate a voltage pulse as they pass the hall effect device in the distributor.This a quote from the manuel."The voltagepulse is used by the EEC-IV system for sensing crankshaft position and computing the desired spark advance based on engine demand and calibration." Do you have a spare distributor to try. Also check ditributor shaft center is not worn. I had a now junk 2.3 turbo that stripped the shaft on 2 distributor.I did not solve that motor. good luck

 

[Green_NV]

Sorry to dig up an old thread, but did this ever get figured out? My car is doing the exact same thing that was mentioned at http://forums.stangnet.com/showthread.php?t=649560

 

[BlownFiveLiter]

Sounds normal to me. The EEC-IV electronically advances the ignition. Pulling the SPOUT locks out the EEC control. The reason your timing advances more, the higher you rev is because the 4 cycles of the engine take less time the faster the RPM, so the mixture needs to start igniting during the compression stroke, in order to achieve a complete burn for the power stroke to happen. Basically, if your ignition isn't firing earlier, you're going to lose power, and probably increase HC emissions from an incomplete burn.

 

[Stinger]

It should idle around 28-30 degrees with the spout in, never 16 at idle...are you sure the distributor was tight when you were testing this?

 

[1badsho]

It should idle around 28-30 degrees with the spout in, never 16 at idle...are you sure the distributor was tight when you were testing this?

hmmmmmmmm

 

[1badsho]

hmmmmmmmm