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Jimmy9190
Dodge Dakota
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3/12/2008
14:47:29
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 Subject: V8 TB on a 3.9
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Hello everybody,
I have been searching for 3 days on here for info on adding a V8 throttle body to my v6 3.9. It's a 2001 with a 5-speed. It was pinging pretty bad and didn't have that much power. I tried 3 different kinds of plugs and had the combustion chambers cleaned and ran 2 bottles of Regane fuel system cleaner through it and it still pinged. So I put in a 180 degree thermostat and put in a set of 3923's from Walmart and the ping is gone. Hopefully for good this time.
This also helped the truck on the top end too. I can pass people a lot easier now and it will go faster on the interstate now if I need to. I found a used TB from a 2001 Ram Van 360 for $65 at a junk yard. I need to know how it will really effect the low end. I have heard and read that it makes no improvement and it makes it slow from taking off and I have heard it will really wake the truck up on the low end and really improve the throttle response at all speeds. Which is really true? What is the real deal?
Also I read if you use a TB from the same year model as your truck you do not need a new throttle cable, and I also read that you do need one or to modify the new tb to accept the one you have. Which is really true on that?
Thanks for the help and sorry for a long post.
Jimmy
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gen1dak
Dodge Dakota
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3/12/2008
18:27:25
| RE: V8 TB on a 3.9
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The pinging is the first issue. The lower temp thermostat may be masking a problem that will be getting worse. A bad intake manifold belly pan gasket will cause pinging that gets worse over time. If the pinging returns, that's a clue. If you look down through the throttle body into the intake manifold, and it looks oily, it's leaking. It needs to be fixed.
The 360 TBI may slightly reduce low rpm power (this is multi-point injection, NOT a situation of over-carburetion so go for it), but it'll breathe better as it revs. You can take more advantage of it by adding 1.7:1 rockers and a better exhaust.
The Magnum powertrains are essentially drop-in systems. The throttle cables aren't nearly so important year-to-year as they are by model, and even then, they're probably very close if not identical....not sure, haven't checked that, but it's not a big deal. If you need to, replace with one appropriate to your truck, as the important issue would be proper length for whatever truck the engine is in.
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Jimmy9190
Dodge Dakota
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3/12/2008
19:54:59
| RE: V8 TB on a 3.9
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Thanks Gen1. As best as I can tell the belly pan is OK. I looked down the TB with a flashlight and did not see any oil at all, only a very light layer of dust. Truck doesn't burn any oil and has been getting consistent good MPG. It has no hesitation or loss of power either. I only buy quality gas and had a vacuum induction service done to clean the carbon and if the ping comes back either I will pull the heads and clean it out myself or I'll have it done professionally. I asked a Dodge dealer about that and they didn't seem very interested in the job. He just said run 89 octane in it, which isn't the right way to fix it either. Plus where I live plain 87 octane unleaded is about $3.30 a gallon and there's about a 20 to 35 cent increase for mid-grade. The prices will only get worse over the summer. So far the 180 tstat and 3923's are working and my MPG is the same as before. I'd like to wake up the engine a little more so I am going to get the V8 tb this weekend and if I get time I may look at the intake and the exhaust too. I probably have something around here that I can connect the throttle cable with, and if not Napa and Advanced are less than a mile away. I'm going to try a better flowing drop-in air filter like the Purolator Premium Plus or Fram Tough Guard and cut a larger opening in the front of my stock air box. I read here that I can get the same effect doing that as with a PVC home brew and I am not a big K&N fan anyway. Midas here might have a good price with a coupon on a better muffler, so I may give them a call too and see what they have. I know I can buy a Dynomax from Advance, but I may not have the tools to remove and install a muffler here at home. Might be worth it to have that done at a shop.
Thanks for the help.
Jimmy
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dakownr
Dodge Dakota
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3/13/2008
09:34:16
| RE: V8 TB on a 3.9
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Regarding the throttle cable issue- I had modified a tb from a '94 360 and installed it on my '96 318 dak. However, all the cable connections on the passenger side were NOT interchangeable. Now, seeing as your throttle bodies are the same model year, you may not have a problem. However, if they don't, it is a simple fix, and it shouldn't require you to cut the throttle cable at all. If it does happen that the brackets aren't interchangeable in your case, and you read this before you go cutting cables, just ask on this thread how to convert the V8 tb and I will gladly help you out. Nothing will need modified, parts will just need to be switched around. Even if it does work, let us know how it turns out!
P.S. If you want, I have a gutted V8 tb that I would be happy to sell you for much cheaper than $65. I still have all the seperate components to it, but it would probably be a little cheaper to ship w/out them, and you would probably need to convert it with your 2001 V6 parts, anyway. If you want to get a quote from shipping, use ZIP code 16673. Let me know, I'll keep a close eye on this thread.
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pete
Dodge Dakota
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3/13/2008
10:56:06
| RE: V8 TB on a 3.9
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Considering you had that ping issue i wouldnt invest in a TB to resolve previous issue might create a new problem, I would start with your air filter upgrade to better setup.Glad that found problem sometimes we overlook the obvious simple things hope you didn't ruin anything internally?? save your $$$
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gen1dak
Dodge Dakota
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3/13/2008
14:15:58
| RE: V8 TB on a 3.9
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On connectors being the same....I guess they changed them as well in the mid-90's. I noticed the coil from an OBDI has a different connector than the same coil for an OBDII setup....price is higher as well. It's always something. Sounds like the ping is just the carbon build-up. Run some Seafoam through it occasionally to help clean things out. Keep the 180 thermostat. That has proven to be a very good, simple mod.
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Jimmy9190
Dodge Dakota
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3/13/2008
14:49:27
| RE: V8 TB on a 3.9
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Thanks for all the help here guys. I did run a can of Seafoam and 2 bottles of Regane in my gas tank. Not all at the same time, it was over the course of 4 tanks of gas. Plus I had a shop do a vacuum induction cleaning for the combustion chambers and fuel system. I think the Regane helped a little more than the SeaFoam and will add it every 5000 miles to help keep everything clean from now on. Pete has a good idea too and I will try to get the TB anyway because it's a real good price and I'd like to have it on my truck. There's another yard here that has a tb off a 2001 Dakota SXT 360 motor but he wants $125 for it. I am very pleased with the 180 tstat & 3923's. I had been trying for a long time to get rid of the ping, and am glad to see it gone. I just hope it stays gone. I will do the air box and tb this weekend then soon as I can will get a new muffler.
Thanks for the help.
Jimmy
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miltonwaddums
Dodge Dakota
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3/14/2008
10:53:03
|  RE: V8 TB on a 3.9
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I did the v8 tb mod on my 2000 v6. I needed a throttle cable. The connections on the TB are different. I dont think it is affected by years or model, just engine (and OBD-I or II). I would just try to buy the cable with the junk yard throttle body, this way you know it matches. The cable is easy to replace.
I never noticed any loss of low-RPM torque, but I had a 5-speed like yours so proper throttle opening was easy to achieve. I added a CAI later and it really helped with proper throttle use, as you could easily hear it begin to bog. The OEM intake system does a god job at hiding these ugly but useful noises.
The only problem someone with an automatic may have is if you go WOT from idle at a stop. This will cause the engine to bog since the tranny is in first and has no more gears to kick down to.
It was BY FAR the best bang for the buck for performance that I did to that truck. The throttle response is probably the most noticeable improvement. While your at it, I'd pick up 12 viper rockers and install those. Reset your computer and give it 50 miles. Your torque and hp will go through the roof and if you can keep your foot out of it, so should your fuel mileage.
In terms of pinging, one thing to try while installing a different TB is making sure the TPS is set to .72. Remember that the PCM doesnt really have common sense and may think that the throttle is open further than it is (like 110% open at WOT) therefore increasing timing, or altering something else to cause pinging. This is just a drunk shot in the dark, but most people report improved performance and mileage with a properly set TPS.
Good luck,
Jay
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Jimmy9190
Dodge Dakota
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3/15/2008
15:54:09
| RE: V8 TB on a 3.9
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Well there's good news and not so good news. I went and got the TB today and it was not from an 01 Ram Van it was off a 1998 Ram Van and so I had to get the Holley ball stud set from the parts store and cut off some parts of the linkage and drill out the stud for the van throttle cable. That seemed to have worked OK but there is a strange delay in the throttle sort of like when you miss a shift. It happens when I shift from 1st to 2nd then 2nd to 3rd, like the cable is too slack. But the cable is straight and tight when idling or when the engine is off, so I don't know what that delay is from. The ball stud on the new tb is about a half inch lower than the stud on my original V6 tb. I don't know if that has anything to do with it. It might just be my truck needs to get used to the bigger shot of air from the tb and it could very well be that I need to adjust to it also. The longer I went on my test drive today the better it seemed to get. The tb sure did help out the response and it seems to have more power when going uphill or passing, but in the lower rpm's it seems I have to give it more gas to get going so I need to drive it more I think. All in all it was a real good mod for not a lot of money and I am very happy with it. I just wish I could have got only the ball stud I needed for a dollar or two instead of a whole assortment for $12.95. But it was good to have on hand all the ones I might have needed.
I took a dremel to the OE air box and cut out the front end larger, and that made a very noticeable difference too. It has a little bit of a howl to it at lower rpm's but I will take that for better performance. Wish I had done that one sooner too.
Now for the not so good news. My belly pan gasket is definitely blown and leaking. With the tb off I got a real good look toward the back, front and sides inside the manifold and I have oil oozing from the sides and collecting in the front and back ends of the manifold. It's not much oil, maybe 2 tablespoons at the very most but that is very likely the cause of the ping I had. So that's the next project. I'll get the Hughes M1 part and fix it the right way permanently. It will probably take me 2 or 3 days to do, though as slow as I am whan fixing my truck. Do you get the best price on the part buying direct from Hughes or does anyone know another supplier?
Thanks for all the help here guys. I appreciate it.
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gen1dak
Dodge Dakota
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3/15/2008
23:06:48
| RE: V8 TB on a 3.9
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Seems like Hughes is usually pretty proud of anything they sell. A little shopping around might be prudent. I hate to say I toldya so, but.... I toldya so!!!
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Jimmy9190
Dodge Dakota
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3/15/2008
23:22:11
| RE: V8 TB on a 3.9
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Yes I know you told me so Gen1. When I "checked" the manifold before the tb was in place and I really couldn't see that much. What I could see looked OK to me. Got to find the parts now and fix it as soon as I can.
I think from reading here tonight that the problem with the throttle control is I tightened the TPS too tight on the TB. I had no idea if it was too tight it would bind up and not work right until I read one of Larry's posts on the TPS mod. Lucky for me if I need another one I have a spare tps from the tb I got at the junk yard today. I just hope that's all it is because the truck is sure not running good right now. The throttle operates OK by hand but when driving it feels like it is too stiff and not accelerating or decelerating right. I'm going to loosen the tps screws tomorrow, check the voltage and try it again.
Any help here is greatly appreciated.
Thanks
Jimmy
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gen1dak
Dodge Dakota
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3/16/2008
10:58:35
| RE: V8 TB on a 3.9
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Have to admit I haven't heard of an issue stemming from the TPS screws being too tight. That's a new one on me.
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ant
Dodge Dakota
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3/23/2008
00:29:47
|  RE: V8 TB on a 3.9
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i have a 89 dakota wt 3.9 v6 and i put a 91 v8 TB on it and it does not run right now i checked the 2 fuel ingectrs and the 1 on the left sprays harder than the 1 on the right could the left 1 be mest up or is that right please HELP!!ME and email me if u would like?
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spkdtch2
Dodge Dakota
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4/02/2008
11:54:13
| RE: V8 TB on a 3.9
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dakownr!!!
hope u notice this, u said u got a v8 tb, i need 1 and cant find 1 near me 2 save my life, reply 2 this thread and ill check back, i reallt need it so your help is very much appreciated
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