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pennywisdomj
Dodge Dakota
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10/24/2007
15:34:44
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 Subject: question on timing
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I just built a new motor and im wondering if timing 0 degrees is best for a .474 intake and .465 exhaust lift
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dakota49
Dodge Dakota
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10/25/2007
18:57:07
| RE: question on timing
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pennywisdomj, try using the stock timing, and go from there. What year do you have? After 92 you can't change the timing. Only the fuel injector timing with the dist. If you have a pre92, then you can try playing with the timing. I have an 88 and I have tried a lot of different settings.
Good Luck
Dakota49
1988 3.9 4X4 5speed
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pennywisdomj
Dodge Dakota
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10/27/2007
01:29:08
| RE: question on timing
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its a 99, i know you cant adjust the timing buy turning the distributor, but i heard you can do it through the computer, right now my timing gun says its about 10 degrees advanced, i think its too much but possibly the computer sets the timing on its own?
i think the idles also set to low because the motor bogs alittle when i take off from a stop. i got the idle set at 1100 in park and it practically stalls when i put it in gear because of the transition, when its in gear its at about 650-700 at idle
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dakota49
Dodge Dakota
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10/27/2007
12:49:22
| RE: question on timing
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Message:
Pennywisdomj, you are correct, the computer controls the timing, but 10degrees is not too much. if fact, if you were to use a timing light that you can dial back, it would probably show some where around 28-35 degrees at about 3000RPM.
Does the engine "ping" or knock? when you are trying to get up to speed fast?
As for the idle, I think its about right. Have you got a vacuum gauge? You could have a vacuum
leak, that could cause the idle to go up when in neutral/park then really drop off in gear.
You said you have a different cam, that can do the same thing if its too radical from stock. Again, check the under hood spec. for tune up information, it should have all the information on it. It will also tell you you can't change anything, the computer does it all. One thing that could affect the idle is the IAC Idle Air Control, if that is dirty it can casue the problems with the idle you are having. The IAC is mounted on the throttle body, remove it carefully, be very careful while cleaning, then use carb. cleaner to clean the throttle body where the IAC came from. It would be easier to clean the IAC by just spraying it down good with the carb. cleaner as well.
I hope that helps, keep us posted as to how things are going.
Dakota49
1988 3.9 4X4 5speed
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daddio
Dodge Dakota
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10/27/2007
14:07:35
| RE: question on timing
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Message:
post the specs on the cam. you may have too much cam for the stock programming to handle. the easy wat to advance or retard the timing a few degress is to modify the CPS.
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pennywisdomj
Dodge Dakota
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10/27/2007
18:26:41
| RE: question on timing
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i lost my sheet that had the specs >:O, i know the lift is 474 and 465 but im not sure of the duration, the guy who made the cam for me said it wasnt going to give me any problems with the computer, i do hear alittle pinging noise when its in idle, but it goes away once you rev it(alittle curious what that is too, i think i might have a rocker arm alittle tight).
there might be a vacuum leak... i dont have a gauge though so im gonna have to check next time i go to work, as for the IAC; i replaced all my sensors with the motor so im pretty sure thats fine.
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J and J Auto
GenII
10/30/2007
01:20:15
| RE: question on timing
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Message:
The base timing is 10 degree's
when idling it will show around a 15 to 20
advance this is all controled by comp
idle is also comp controled if you have youe
throttle plates open to far and the IAC idle air
control would be at 0 steps and this will cause
a transition bog fix this close the plates until
your steped 15 to 30 as the trottle opens so does
the IAC so when youlet off it will slowly step
down to reach idle speed without stalling
Also if your cam is a little hot the vac signal
at the map will be low, plug the throttle body
port for the map and run a line to the test port
on the drivers side for the map signal it will
be higher
Now remember every time you change the throttle
plate position you will need to start and stop
the truck 3 times to relearn idle
You can plug the intake hole for the IAC and the
motor should slow around 200rpm and rev up when
you open it this will also tell you your IAC is
controling the idle this will get the bog out and
must be set right or it will never idle corectly
Larry
J&J Auto
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pennywisdomj
Dodge Dakota
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10/30/2007
19:50:09
| RE: question on timing
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Message:
looks like i have a more important problem right now.....im starting to hear a knock when the engine gets to running temp. i hope a bearing didnt spin. any ideas on how i can find out what it really is. i have a 195 degree thermo and i also heard the higher themorstats can cause pinging? should i move down to a 180 and maybe even use a thicker oil?
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shadetree
Dodge Dakota
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10/31/2007
06:16:56
| RE: question on timing
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Are you sure its a bottom end noise. Ive had heads come back from machining and after install sound like there is a ping or knock, but it was actually the valve seat coming out of the head and being smacked by the piston.
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pennywisdomj
Dodge Dakota
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10/31/2007
09:27:55
| RE: question on timing
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Message:
did this happen to you only when the motor got warm? because i didnt have this issue with the motor for the first 100 miles i drove it
i broke it in for 30 minutes at 2500 rpm and changed the oil, i dont know what may have caused it to start knocking
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shadetree
Dodge Dakota
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10/31/2007
11:02:41
| RE: question on timing
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Message:
Ya the engine Im refering to only had 345 miles on it after the heads were installed. It did happen when the engine was hot. The machinists excuse was that the head expanded quicker than the seat he installed, but I beleive he just messed up machining. Run a compression or leak down test on you engine cause thats how I found that one.
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