| From | Message |
Nathan Cain
Dodge Dakota
11/06/2001
16:36:49
|
 Subject: The dreaded backfire...
IP: Logged
Message:
Everybody here has probably answered this question many times before but I just discovered this site... so I have a very loud back fire between gear shifts and when using engine as brake. I have a straight pipe with glasspack exhaust ( pretty much stock until where the cat used to be then I chopped it off for 2 1/2 " pipe with a single glasspack. Its loud and beautiful. A true badass sound, well anyway even before I made this modification it backfired with the stock exhaust system, just alot quieter. It's a 94 cc 4x4 5spd 5.2L V8 with about 120k so its getting up there. But still it shouldnt backfire like it does, sometimes I scare pedestrians, which is funny but at other times it sucks. It backfires more when its cold and once it gets to operating temp it hardly backfires at all. I did replace the plugs about 3 months ago with mopar stock plugs with a brand new coil, disb cap and pickup coil. There is alot of valve train knock when rapping it out so I think its gonna have some major problems before long. Plus 120K + Glasspack + 20 year old lead foot = hard driving, its still got alot of balls for high mileage but I just cant stand the backfire anymore...
Please help me out
Nizate
|
Clevite 77
Dodge Dakota
11/06/2001
21:58:39
|  RE: The dreaded backfire...
IP: Logged
Message:
I could be wrong but i think it has to do with no "cats" you said it did it with the stock exhaust, i bet the cats were bad???? I know it's a Dakota but my buddy has a 98 cobra conv. big on mods, he took off the cats and it does the same exact thing. I bet when you rev it up and as it returns to idle it back fires again, his does
|
Billy
Dodge Dakota
JOIN HERE
10/21/2003
22:02:03
| RE: The dreaded backfire...
IP: Logged
Message:
I do agree with the bad cat. reply. You have a later model truck designed to run with cats. especially as far as the computer is concerned. Removing the cats would infact change the computers factory set air/fuel mixture, causing excess raw fuel to be released through the exhaust and what you get is exhaust combustion. Similar to the old school exhaust with flame throwers. Just a thought...
|
Chris
Dodge Dakota
JOIN HERE
10/21/2003
23:52:49
| RE: The dreaded backfire...
IP: Logged
Message:
my 91 318 dakota would backfire a lot then i found out my O2 sensor (i think it was) was going out so i replaced it and it hasn't backfired once. who knows i have no clue i suck at mechanical stuff.
|
GraphiteDak
GenIII
10/22/2003
00:06:33
| RE: The dreaded backfire...
IP: Logged
Message:
The popping sound could be cold air rushing back into the exhaust. It's usually noticed when shifting (RPM's dropping) or if you engine brake.
Worse yet, it could be UNBURNED gas entering the exhasut, but I think that would be worse as the exhaust heated up rather than getting better.
You probably just have too big of pipe and the glass pack will make it worse.
2003 Graphite QC 4X4 4.7 Auto 3.55
Home Brewed Cold Air Intake, Flowmaster 40 series, Modified TPS to .72VDC, Modified IAT. 160° T-Stat.
|
billy tevai
Dodge Dakota
JOIN HERE
10/22/2003
10:51:21
| RE: The dreaded backfire...
IP: Logged
Message:
yes big pipes are bad. If you are running a V-8 then you don't want to run pipes bigger then 2.1/4- to 3". Any bigger then that and your better off running open headers. Because as air cools it becomes more dense, this dense air creates back preassure causing your pistons to have to work twice as hard to get it out of the cylinders. bigger pipes cause exhaust gases to cool, you don't want that.Also exhaust leaks are very bad so conections should be welded. clamps work but due to engine vibration and heat these clamps over time will break their seal..
|
Kowalski
Dodge Dakota
JOIN HERE
10/22/2003
16:55:03
| RE: The dreaded backfire...
IP: Logged
Message:
You know, Nathan hasn't posted here in the last couple of years, so maybe he burned his truck up. What he describes are typical of an engine running lean, a condition he worsened with those exhaust mods...
|
BadMoFo
Dodge Dakota
JOIN HERE
10/22/2003
17:47:12
| RE: The dreaded backfire...
IP: Logged
Message:
Why do some people dig through two year old posts and reply as if it was asked today?
|
xplikt
GenIII
10/23/2003
11:10:27
| RE: The dreaded backfire...
IP: Logged
Message:
Because this site is indexed very well in search engines and people come in through there, not the search on the site itself. No one bothers to look at the date. Maybe a notice should be added when you reply if the last post is older than 6 months.
-Mike
http://www.dodgetruckworld.com/xplikt/
2002 2WD RC SLT 4.7L 5spd 3.92 LSD
MBRP Single in/out | straight piped 3rd cat | turndown tip
Full Hotchkis and RAS
Shaved emblems and antennae
150BM fan | removed clutch | HD Radiator
R/T wheels on 275/40/17 Dunlop 9000s
|
gen1dak
Dodge Dakota
JOIN HERE
10/23/2003
11:38:28
| RE: The dreaded backfire...
IP: Logged
Message:
This is a fuel issue. Simple as that. Either too much, or not enough. Pan gasket in the intake will cause a run lean condition. Bad O2 sensor will cause a rich condition. Do yourself a favor and fix both. Start with the O2 sensor. A rich mixture will allow unburnt fuel into the exhaust where it lights off afterwards. It probably got worse after the cat was removed because the cat acted as a baffle.
|
| | P 1 |
|
Post a reply to this message:
Username Registration: Optional
All visitors are allowed to post messages
|
