Vacuum Advance
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Vacuum Advance
Okay, I thought I had finished my DuraSpark II conversion (watch those wiring harnesses, the one I got had the ground and sensor leads reversed). The system is running good without the vacuum advance connected, but once the vacuum advance is connected it pings badly. The idle timing seems set pretty good, do I just need to retard it (I'm worried it will throw idle out of whack). All the components are new from AutoZone for a 1981 351W (distributor, ignition module). The engine currently in there is a 1983 351W which used to have the EEC III system (which, by the way is still hooked up except for the ignition module if that helps anything). Any suggestions on what I can do to get this thing running right?
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From: Chandler,Arizona - USA
Vacuum Advance
Sorry I can't help you with your question, but, I have a question for you. Did you get the wiring harness at Autozone? Seems that the wiring harness is the hardest part to get. I have an '85 F150 w/ the 300 I6 that I am looking to convert to DSII. Not in any hurry, just acquiring the parts. Good luck with your timing problem.
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Vacuum Advance
Originally posted by PaulzF150
Sorry I can't help you with your question, but, I have a question for you. Did you get the wiring harness at Autozone? Seems that the wiring harness is the hardest part to get. I have an '85 F150 w/ the 300 I6 that I am looking to convert to DSII. Not in any hurry, just acquiring the parts. Good luck with your timing problem.
Sorry I can't help you with your question, but, I have a question for you. Did you get the wiring harness at Autozone? Seems that the wiring harness is the hardest part to get. I have an '85 F150 w/ the 300 I6 that I am looking to convert to DSII. Not in any hurry, just acquiring the parts. Good luck with your timing problem.
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From: Mechanicsville
Vacuum Advance
I am speaking from experience. If you set the idle timing at 8 degrees and you have the vacuum advance vacuum hose attached above the throttle plate on your stock engine with at least 87 octane gas there should be no spark rattle.
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From: Memphis, TN
Vacuum Advance
I'd recommend following the tune-up procedure printed on the emissions sticker (the one with the vacuum diagram), then use a vacuum gauge to adjust the timing. It's better than using a light to set an exact number because it accounts for the current condition of your particular engine.
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Vacuum Advance
Make sure the egr valve is working. You said you have the original set-up, so if you are running the original carb, you need the egr to keep it from pinging. Or go buy an aftermarket carb that is non-emissions type.
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Vacuum Advance
Sorry, some more background here. It was an EEC-III system so it originally had the 7200 VV carb on it. That was replaced with a 2150 recently which caused problems with the EEC-III system (because it had no TPS, therefore wouldn't advance the timing on throttle changes and pinged). So I replaced the EEC-III ignition module with a Duraspark II setup (but left the ECU installed and connected, I was hoping this would keep the emissions stuff working).
Unfortunately, I don't have the information for setting timing on the '81 donor system. Since I left the ECU in I'm assuming the EGR is still working (but haven't verified yet, I will go look). According to Haynes the EGR with EEC-III is electronic so it should work.
Unfortunately, I don't have the information for setting timing on the '81 donor system. Since I left the ECU in I'm assuming the EGR is still working (but haven't verified yet, I will go look). According to Haynes the EGR with EEC-III is electronic so it should work.
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Vacuum Advance
Okay, I messed with it some more this morning. It does not ping at idle (is this normal), but it does ping at speed at a certain throttle point. I retarded the timing from 10btdc to 8btdc and test drove it again. I did not notice a change when I did this. The engine always starts pinging at the same throttle point and only when moving. I even tried removing the ECU to see if that helped anything (it didn't).
So I guess what I'm asking is if all of that is normal and whether I need to continue messing with the timing or whether there might be something else wrong.
So I guess what I'm asking is if all of that is normal and whether I need to continue messing with the timing or whether there might be something else wrong.
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