Re: New idea on engine backfiring/popping/burbling

From: baddak@excite.com
Date: Mon Feb 14 2005 - 00:12:37 EST


In article <cupbk5$5gu$1@bent.twistedbits.net>, sbarnett56@adelphia.net
("BlackDak93") writes:

      The truck originally had cruise, but when we did the swap, we also took
off a lot of the unnecessary stuff, like cruise and air. The truck was not to
be used for daily use anymore. Sorry, can't help with the cruise control
problem.

Mike

>
>
> Thanks,
> No, I don't have a PCM for an automatic. Mine was a 3.9 with a 5-speed
> originally. I am using a '93 RAM 5.2L-5-speed PCM. I wonder, did your
> friend's truck have cruise control? If it did, does it work now the
> automatic's PCM?
>
> I have used a 93 MP PCM that is really intended for an automatic, and it
> backfires too, but I had to disconnect the Park/Neutral switch line before
> my cruise control would work, but even then it won't disengage when I press
> in the clutch. I didn't like that, so I went back to the factory PCM.
> thanks for the info.
>
>
> <baddak@excite.com> wrote in message
> news:cup54q$epi$1@bent.twistedbits.net...
> >
> > In article <cuobfb$d9p$1@bent.twistedbits.net>, sbarnett56@adelphia.net
> > ("BlackDak93") writes:
> >
> > My friend had the same problem with his 93 after we swapped in a
> > 5-speed.
> > We thought the truck had to use a 5 speed pcm. We used the pcms (factory
> > and
> > Mopar Performance) from my 95 318 5-sp, and the truck did just that,
> > backfired
> > heavily out the exhaust on the 1-2 shift, and then dropped off through the
> > upper gears. The truck seemed to have a lot less power as well. Just for
> > the
> > heck of it we put the factory pcm (automatic) back in and it ran fine. I
> > am not
> > sure if you tried that, but thats what worked for us. I dont think it
> > would be
> > an exhaust issue. My friends truck has MP headers (Doug Thorley), stock
> > cat and
> > a Borla cat-back exhaust. My 95 has some popping/burbling through the
> > exhaust,
> > but I think that was normal with 95-96 5-speed trucks, but it is
> > definitely not
> > backfiring. Just my .02, hope it helps.
> >
> > Mike
> >
> >
> >
> >
> >
> >>
> >>
> >> It does backfire, mostly between 1st and 2nd gears but the popping and
> >> burbling which happen anytime I decelerate are, at least in my opinion,
> >> much
> >> more than what could be considered normal. My exhaust is not extremely
> >> loud.
> >> It is actually pretty mellow compared to a lot of trucks around here. I
> >> have
> >> shorty headers, a high flow cat, a Magnaflow XL with 2.5" dual tailpipes.
> >> The 2.5" tailpipes are probably too much, but I have had 2" and 2-1/4"
> >> and
> >> it did the same thing. It did the same with a stock muffler, a turbo
> >> muffler, a Flowmaster 50 an IMCO chamber muffler and with resonated tips
> >> and
> >> a glass pack between the cat and the muffler. I even took the advice of
> >> the
> >> mechanic and dropped the factory 3" pipe bwtween the cat to the muffler
> >> down
> >> to a 2.5" pipe. I wish I had not done that. It made no difference and it
> >> messed up a pretty sweet looking exhasust system.
> >> "steve preston" <steves287dak@yahoo.com> wrote in message
> >> news:20050213193645.63951.qmail@web41828.mail.yahoo.com...
> >> >
> >> > I`m not really sure of the noise you describe.
> >> > Backfiring is one thing,but popping or burbling a
> >> > little bit when going down a hill,or when the engine
> >> > has no load on it seems normal to me. Mine does
> >> > that,and I`ve seen it on many vehicles with a "loud"
> >> > exhaust. (My Dak has a conventional exhaust into a
> >> > race muffler,then split out to the rear.) It seems
> >> > like once the engine has gotten the vehicle up to
> >> > speed and you decelerate,there`s no load on it anymore
> >> > and it will sound different because your transmission
> >> > and driveline are pulling up the RPM`s that would
> >> > normally have a tendency to drop. But please keep in
> >> > mind that I have no official training as a mechanic.
> >> > However,I did stay at a Holiday Inn Express last
> >> > night. :) Steve P.
> >> >
> >> > P.S. I start my new job tomorrow,in heating and
> >> > cooling. After twenty years of electronics repair,I am
> >> > conceding to the Chinese,and Walmart. So if your $169
> >> > 27" TV breaks,do what everybody else is doing,and go
> >> > buy a new one that will last 1/10 as long! :)
> >> >
> >> >
> >> >
> >> > --- BlackDak93 <sbarnett56@adelphia.net> wrote:
> >> >
> >> >>
> >> >> I brought this topic up a few months ago, and I am
> >> >> still trying to find a
> >> >> solution to it. The problem is my '93 Dakota 5.2L
> >> >> with 5-speed manual,
> >> >> backfires through the exhaust on deceleration. I
> >> >> have been through hundreds
> >> >> of hours and many more dollars trying to resolve it.
> >> >> I have been through
> >> >> everything I can and been to several shops,
> >> >> including my friendly Dodge
> >> >> dealer to have it checked out. The Dodge technician,
> >> >> charged me $180.00 to
> >> >> tell me that there is abosutely nothing wrong with
> >> >> the engine. He believed
> >> >> the problem to be my exhaust. To make a long story
> >> >> short, it is not my
> >> >> exhaust, although it does make it more noticeable.
> >> >> Stock exhaust did the
> >> >> same thing. The second leading theory is that this
> >> >> is normal for Dodge
> >> >> Magnum engines, and the problem is worse with a
> >> >> manual transmission (it pops
> >> >> back when I let off the gas to shift). I am not
> >> >> willing to concede that this
> >> >> is normal, although I have come to the decision that
> >> >> the problem is the
> >> >> manner in which the PCM controls the fuel. My
> >> >> primary basis for this theroy
> >> >> is that when I install a different PCM ( I have
> >> >> three) the
> >> >> backfiring/popping/burbling disappears for about
> >> >> three days until, I assume,
> >> >> the PCM gets itself reprogrammed. Then the popping
> >> >> comes back. Every
> >> >> technician I have been to is unwilling to accept any
> >> >> other theory except the
> >> >> exhaust system and will not objectively pursue any
> >> >> other ideas. I am not
> >> >> going to put the exhaust back to stock just to prove
> >> >> them wrong. I have been
> >> >> studying my manuals, and have decided to try a 94 or
> >> >> 95 PCM, to see if they
> >> >> would work any better. I believe that a later model
> >> >> (pre-'96) PCM will still
> >> >> work. All the connections are the same with the
> >> >> exception of pin 5 which is
> >> >> a signal ground that goes to the DataLink connector.
> >> >> On the later model,
> >> >> this line is still grounded, but not connected to
> >> >> the PCM.
> >> >>
> >> >> I have a few questions: First, I would like to hear
> >> >> what you guys all think.
> >> >> Any new ideas about this? Has anyone tried running a
> >> >> 94 or 95 PCM on a 93?
> >> >> Also does anyone have a 94 or 95 PCM for a
> >> >> 5.2L-5speed with Federal
> >> >> emissions that they would part with? I would rent,
> >> >> buy or borrow just to try
> >> >> my theory. I have searched the internet and I
> >> >> believe that part number
> >> >> 56028262 is the correct part. There may be a
> >> >> 56028341 also, but I can't
> >> >> verify if that number is correct. Or does anyone
> >> >> have a Mopar Performance
> >> >> PCM number 5249542 they would sell? There is a
> >> >> remanufactured PCM out there
> >> >> made by a company called A-1 Cardone. Has anyone
> >> >> ever used one of these? I
> >> >> am desperate to get this fixed. I have had this
> >> >> truck for over 10 years and
> >> >> I love the truck. I spent a lot of money swapping in
> >> >> this engine but it
> >> >> makes me want to park the truck and not even drive
> >> >> it anymore.
> >> >>
> >> >> Any new ideas or help would be appreciated. BTW, I
> >> >> have gone through the
> >> >> entire intake/exhaust systems checking for leaks.
> >> >> Replaced the leaking belly
> >> >> pan gasket. All the sensors have been replaced and
> >> >> checked. Compression is
> >> >> good. Timing is good according to the Dodge tech.
> >> >> Distributor cam sync has
> >> >> been set. Vacuum has been checked. All the normal
> >> >> stuff.
> >> >>
> >> >>
> >> >>
> >> >
> >> >
> >> > =====
> >> > Steve P.
> >> > Two-thousand one (2001) Flame Red Dodge Dakota Sport RC 4X4,4.7L
> >> > eight-piston w/3.92 limited-slip,air,cruise,tilt,knob(not
> >> > shifter)induced
> >> > four by,with optional hand crank windows and finger locks that added
> >> > substantially to the overall cost. Steigerperformance air intake
> >> > providing
> >> > twenty additional RWHP (ten at the flywheel). PLUS,a custom
> >> > dual-exhaust
> >> > than is real loud,with gigantic 2 1/4" pipes sticking out the
> >> > back,reminiscent of warship cannons primed and ready for the heat of
> >> > battle. The other mods (headlight and taillight covers and black step
> >> > bars) do not add significantly to the speed of this vehicle,but are
> >> > there
> >> > purely for intimidation purposes,as the markings of a cobra signify
> >> > it`s
> >> > deadly potency. Put simply,this truck cannot be stopped.
> >> >
> >> >
> >> >
> >> > __________________________________
> >> > Do you Yahoo!?
> >> > Yahoo! Mail - now with 250MB free storage. Learn more.
> >> > http://info.mail.yahoo.com/mail_250
> >>
> >>
>
>



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