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christopher
Dodge Dakota
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7/19/2005
20:14:55
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 Subject: rpm shifting
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i have a '99 dakota r/t. when i take off and gas it my rpms jump up to about 6500. which is way past the red line. i dont know if all do that or if it is just mine. my truck also has a shift kit in it but i am not sure what kind because i bought it with it in. if anybody knows anything about this please let me know. thanks
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ticats
Dodge Dakota
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7/20/2005
07:58:08
|  RE: rpm shifting
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Am I correct in interpreting what you're are writing is that it will not shift into 2nd on a WOT acceleration? If I am, I'm not surprised that you have this problem although I am a little surprised that the motor revs to about 6500. I would think that it would have hit the rev limiter by then.
Odds are that the shift kit is a Transgo. If so, many have experienced this problem.
While there could be many causes in the tranny, I think that high line pressure could be a likely cause. The PCM gets confused if pressure exceeds about 100 psi (according to those knowledgeable with our trannies). GM and Ford computers seem to able to handle up to three times that pressure.
I've had the WOT 1-2 no-shift since 98 and have been looking for an inexpensive fix ... adjusting line pressure, replacing gov. press. solenoid/sensor, etc.
After 7 years of searching, I've finally corrected it by putting a 100K 1/2-watt resistor (plus some adjusting of the TV cable) to the wire running to pin #31 (5V power supply line ... should check the pin # for your Dak) of the center connector at the pcm. What this does is to "cap" the return signal from the governor pressure sensor so that the pcm nevers sees 100 psi or more pressure. Many R/T owners have put in this fix to overcome their shift problems.
I've noticed that this fix drastically lowers my 2-3 shift point (low 4000s on mine) but it can be overcomed by doing manual shifts, which I do at the track anyways.
It's worth the try. With a little creativity, you can easily design a way to swap use with the resistor or use without it. HTH.
ticats, ontario, canada.
97 Dak CC Sport, 5.2L, 44RE, race weight 4180 lb, pb 13.76 @ 99.65
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kevin
Dodge Dakota
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7/20/2005
17:37:29
|  RE: rpm shifting
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Ive had my R/T for a little while now and i always drove a manual trans.. but ive never really raced an automatic, one guy i talked to that supposedly had an R/T said just to hit the overdrive before the start , but that didint seem to fit tha bill because my problem in the first place was that i kept hitting the rev limit when i thought that it would shift into gear by its self. I know i could shift first and second, but i fell into that same problem when i went to the 1/8 mile track, because when i shifted into 2nd it didnt even shift unless i let off tha gas for a good sec.. I know a chip would hopefully eliminate that problem but i really was hoping to find someone that atleast knew what they where talking about so i could learn instead maybe screwin my own truck up.
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GraphiteDak
GenIII
7/20/2005
18:39:40
| RE: rpm shifting
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A chip wont change your shifts one bit on a R/T since it uses a tranny with a mechanical valve body. Either your TM cable is mis adjusted, or you have a sticky valve in the tranny.
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christopher
Dodge Dakota
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7/21/2005
08:24:17
| RE: rpm shifting
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my R/T seems like it doesnt have a rev limiter on it. im not sure but would a shift kit make the truck rev higher. like when i take off and going from first to second the rpms will rap real high. i have to let off the gas for a second to keep it from going to high. if i put a msd 6al ingnition with a rev limiter would that fix my it.
christpher
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ticats
Dodge Dakota
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7/21/2005
09:37:22
| RE: rpm shifting
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It sounds like your R/T has had a custom flash on the computer (any idea what computer is on? ... stock or MP) to raise the rev limiter. The MP PCM has the rev limiter set to about 6000. Unless the previous owner has installed beefed-up valvetrain components to handle 6500 or above rpm, some serious damage to the motor can happen.
You can adjust the rev limiter with a MSD 6AL but instead of using a fuel cutoff it will be by an ignition cutoff which could mean that there might be a good chance of raw fuel being left in the engine when it restarts.
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daveshotdako
Dodge Dakota
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7/28/2005
12:17:44
| RE: rpm shifting
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on a msd ignition, the rev limiter works by randomly not firing on one cylinder but it alternates between all of the cylinders to prevent loading up one cylinder. if anything a msd rev limiter is probably the safest rev limiter there is. instead of cutting off the fuel and creating a lean burn condition which could damage the engine at high rpm, it just drops fire to random cylinders and then fires them on the next cycle to burn the fuel out of them. i have had an msd on my jeep for a long time and it helps on a well modified engine but not so much on a stocker. one great thing about it is running a .060 spark plug gap if you have a upgraded coil as well. hope this info can help all you fellow dakota owners.
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ticats
Dodge Dakota
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7/28/2005
19:12:24
| RE: rpm shifting
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daveshotdako ... my bad for assuming that rev limiter of the MSD worked that way :-( Will be more careful of my facts when posting in the future.
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daveshotdako
Dodge Dakota
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7/29/2005
09:53:15
| RE: rpm shifting
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its no problem. i have installed quite a few msd ignitions and i have always had great response from these units. i want to get one for my dakota but i just havent had the money yet. if anyone needs any info on these units feel free to e-mail me at davethomas2184@yahoo.com.
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Christopher
Dodge Dakota
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7/30/2005
05:52:47
| RE: rpm shifting
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so...you think a msd 6al with the right rpm module will make it shift were i want it to without messing up anything.
also when i install my msd, which rpm module should i install with it. you think 5400rpms is good? a little higher or lower?
thanks for all the help!!
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