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Terminals to jump for timing set - resolved; Terminals to jump for timing set - resolved
Topic Started: Aug 26 2013, 04:11 PM (1,314 Views)
j63812f
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J R

Regarding the two terminals that we have to put a jumper on to set timing, mine on my 96 stopped working some time back and its been a guessing game since. In other words I put the jumper in there ( a paperclip), and the ecm doesnt release the timing. It used the drop the idle immediately.

Now on our other 96, the same thing, no response. Has anyone ever encountered this? I think its odd that we have TWO. Makes it kinda hard to set the timing. :hmm

Thanks.
Edited by j63812f, Oct 6 2013, 07:30 PM.
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Old Man


sounds like you have the wrong terminals crossed---re check the diagram that is on the underside of your hood.
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j63812f
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J R

OK well we are back at it again with both cars tonite, was gonna trace the wires back to the ecm. Thanks.
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j63812f
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J R

WEll, there are only two terminals to jump on the LOWER left of the plug, and if you turn it around there arent two, just one. The picture under the hood is pretty clear.

We traced the wires back to the ECM plug and they are good, the both have continuity. But when jumped, neither car releases the timing.

I guess I will try to find another ECM ad see if it responds. We've had these cars for years and have set the timing on them multiple times after repairs. PUZZLED. :banghead
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Woodie
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Bad ground
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j63812f
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J R

Still no go........

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Edited by j63812f, Aug 27 2013, 10:57 AM.
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j63812f
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J R

Just an update, if anyone is interested. We both have Ultraguages in our cars. Turns out the Ultraguage, when actively plugged in, keeps the ECM from releasing the timing for setup. It hit me today like a brick, and when we unplug the Ultraguage and put the jumper on, the ECM drops the idle and brings the mark back to where we can see it.

PROBLEM Solved!!

Who'da thunk.
Edited by j63812f, Oct 6 2013, 07:31 PM.
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JellyBeanDriver


Good to know. I had a 1991 Sentra SER and no matter how I followed the service manual I could never get it into 'set base timing' mode. Never, ever. It sucked.
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j63812f
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J R

JellyBeanDriver
Oct 6 2013, 09:09 PM
Good to know. I had a 1991 Sentra SER and no matter how I followed the service manual I could never get it into 'set base timing' mode. Never, ever. It sucked.
Wow, and you had an ultraguage in it? Maybe I should write them. I bought three of em.

I DO like them, great way to really do tuning and see immediate results.
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JellyBeanDriver


j63812f
Oct 6 2013, 10:44 PM
JellyBeanDriver
Oct 6 2013, 09:09 PM
Good to know. I had a 1991 Sentra SER and no matter how I followed the service manual I could never get it into 'set base timing' mode. Never, ever. It sucked.
Wow, and you had an ultraguage in it? Maybe I should write them. I bought three of em.

I DO like them, great way to really do tuning and see immediate results.
No, no ultragauge. It wasn't even OBDII.

I'm just sympathizing with you when you couldn't get it into base timing mode.
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Flash
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53 mpg last trip

I've seen this mentioned in my service manual. I didn't jump out the plug, just used a timing light and set it at 5 deg before TDC.
Car runs, what does jumping it out do?
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Woodie
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Flash
Oct 7 2013, 12:29 AM
I've seen this mentioned in my service manual. I didn't jump out the plug, just used a timing light and set it at 5 deg before TDC.
Car runs, what does jumping it out do?
The engine control computer adds quite a bit of advance to the base timing, 10 - 12° at idle, more at speed. When you jumper that connector, the ECM stops adding timing, so you're adjusting the mechanical setup inside the engine. If you set yours to 5° without jumpering, then your ignition timing is WAY late. You're loosing a lot of power and mileage compared to what you'd get with the timing properly advanced. Distributor should right about in the middle of the slot when everything is right.


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j63812f
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J R

Flash
Oct 7 2013, 12:29 AM
I've seen this mentioned in my service manual. I didn't jump out the plug, just used a timing light and set it at 5 deg before TDC.
Car runs, what does jumping it out do?
Wow bud, you probably have your timing retarded like 7 or 8 degs now. Cant possibly run well!!
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Mythstae
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j63812f
Oct 6 2013, 07:21 PM
Just an update, if anyone is interested. We both have Ultraguages in our cars. Turns out the Ultraguage, when actively plugged in, keeps the ECM from releasing the timing for setup. It hit me today like a brick, and when we unplug the Ultraguage and put the jumper on, the ECM drops the idle and brings the mark back to where we can see it.

PROBLEM Solved!!

Who'da thunk.
That is SUPER interesting :hmm
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Flash
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53 mpg last trip

I've got a 3Tec econo cam with a 6 deg timing gear. I was afraid of shorting out something with the jumper. I have 5 wires coming from that plug, and the book said the bottom two on the left. You can flip the plug over and still have two wires on the bottom left. What is "up" on this plug?
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