| From | Message |
Rob Cooley
Dodge Dakota
JOIN HERE
3/17/2002
15:19:48
|
 Subject: acceleration hesitation!!!
IP: Logged
Message:
Hi, all, I desperately need some advice!
I have a 94 Dakota with the 3.9 V6, 5 speed, 4x4 that is getting older(sigh), with just over 100,000 on the odometer. I've had it since it had
30K miles, and it's really never given me much trouble, except for one thing. Since new, it has had a rough running characteristic when first
started up, hot or cold, where it backfires once or twice through the muffler as the engine decelerates between 1st, 2nd, and 3rd gears.
When it was under warranty, there was a TSB out from the factory that specified replacing the PCM to fix this condition. Well, two (warranty-covered) replacements later, nothing changed. Several professional fuel injection tuneups ($$$), and home-made maintenance efforts later, no improvement.
Once the warranty expired at 75K, I chose to live with it- warm it up, let it sit after starting for a minute, problem solved. I mean it wasn't bad,you just had to remember to let her sit and warm up a bit immediately after starting, and then she ran like a top.
Well, about 10,000 miles ago I put on a Magnaflow XL free flowing muffler and a K&N air filter in a nice chrome Edelbrock filter mount, and all was
well, it breathes much better, more power, sounds real good, etc. Put 31" Michelins on it, slowed down a bit, but looked cool, and it still ran fine
(no reason for tires to affect how the engine runs anyway). She ran fine for the longest time.
But, three weeks ago, it began to hesitate and stumble on hard acceleration, and later, began to actually backfire loudly through the intake on half to full throttle acceleration. It does it most on cold or cool days when not fully warmed up, popping and hesitating quite significantly when you mash the pedal to the floor or more than halfway (highway merging situations, etc). Not acceptable!
The backfiring and hesitation eases somewhat when the engine's warmed up, but it will do it every time, warm or cold, between 1900 RPM and 2800 RPM at half to full throttle in second, third, and fourth gears. I took it to a mechanic friend, and his diagnostic computer showed that all sensors were according to the computer, working properly, and that the computer had not
recorded any codes that indicated any system malfunctions or maintenance needed. Even the timing seemed to be set properly. The check engine light has never come on during all of this. I ran an entire can of carb & choke cleaner through the throttle body (it's a TBI
fuel injection setup) just in case something was clogging the intake system, but it made no change at all.
So basically, when I tromp the gas, and she winds up to 2100 RPM, she pops like a firecracker through the intake and into the air cleaner, hesitates, and the overall power curve while accelerating feels a little bit lumpy and
uneven, like something's holding her back to some degree. It's still pretty much driveable when warmed up, but I know something's not right, and am afraid it'll leave me stranded somewhere, you know? It's much worse when she's cold first thing in the morning, but the problem persists to some extent even when she's fully warmed up. Seems like something's screwing up the air-fuel mixture and/or the ignition (something's affecting the way the computer delivers fire to the spark plugs???). Any ideas?
PCV valve? EGR valve? O2 sensor? Coolant sensor? Anything?!? Timing Chain?
I definitely can't afford a multi-hundred dollar adventure with the local dealer, and am very capable of most repair work on my truck, so any ideas would be greatly appreciated!!!!
Thanks!
Rob
|
Dakota Bob
GenII
3/17/2002
16:07:04
| RE: acceleration hesitation!!!
IP: Logged
Message:
Check your fuel pressure 35 to 45 psi is good. could be a clogged injector. bad EGR, Intake leak,sticking valve. Check the small things first I got these ideas from my Haynes Auto Manual. I have a 94 also with 106k on it. Its all ways had a miss to it when I first got it I found some replacement injectors on ebay and put them in and runs great now. Hope this helps
Bob
Cincinnati
Jet chip stage 1 JBA Headers,19# fule Injectors,Flow master 40s Auto Lite 3923 K/N Chrome Filter 180 T Stat ,TPS adjusment,Flometrics throttle body
|
LI Blackdak
Dodge Dakota
JOIN HERE
3/17/2002
16:41:46
| RE: acceleration hesitation!!!
IP: Logged
Message:
yeah i dont think hesitation is a strong enough word for this awful engine
|
rob cooley
Dodge Dakota
JOIN HERE
3/17/2002
17:20:33
|  RE: acceleration hesitation!!!
IP: Logged
Message:
Thanks Bob, I'll try your ideas. Appreciate your input.
-Rob
Anyone else have suggestions?
|
Dakota Bob
GenII
3/17/2002
19:24:55
| RE: acceleration hesitation!!!
IP: Logged
Message:
Your welcome. Let us know when you find out what it is.
Bob
Jet chip stage 1 JBA Headers,19# fule Injectors,Flow master 40s Auto Lite 3923 K/N Chrome Filter 180 T Stat ,TPS adjusment,Flometrics throttle body
|
3RD DAK V6
Dodge Dakota
JOIN HERE
3/22/2002
14:24:53
| RE: acceleration hesitation!!!
IP: Logged
Message:
HEY ROB,, I HAD A "93 DAK 3.9 THAT WOULD MISS AND BACKFIRE AT DIFFERENT TIMES, REPLACED MANY SENSORS AND THE COMPUTER,, FINALLY I FOUND THE PROBLEM, AND A MECHANIC MAY HAVE NEVER FOUND IT OR CHARGED ME A FORTUNE. THE TIMING SENSOR IN THE DISTRIBUTER CAP WAS COMPLETELY BROKE LOOSE!! IT IS A ROUND PIECE OF FLAT METAL WITH A TAG ON IT IN THE DIST. CAP THAT PASSES THROUGH A SENSOR AS THE DIST SHAFT TURNS. WHEN IT TURNED IT WOULD BE LOOSE AND VIBRATE AND THE COMP. LOST TIMING. CHECK THIS IT IS SOMETHING A LOT OF PEOPLE WOULD OVERLOOK.
|
rob cooley
Dodge Dakota
JOIN HERE
3/22/2002
20:07:23
| RE: acceleration hesitation!!!
IP: Logged
Message:
Hey, all, thanks so much for your advice.
I replaced plugs, wires, dist rotor & cap, pcv valve, and O2 sensor. Problem solved!!!
I think it was the distributor cap- the contacts on the cap for cylinders 2 & 3, immediately behind the throttle body were completely corroded and gross. The contacts inside the cap were white with corrosion. The rotor was a piece of garbage. The spark plug electrodes were reddish in color, something I haven't seen before. The plug wires weren't bad, but replacing them is just a good idea.
I have afuel filter to install, but since it hasn't, and the problem is fixed, obviously that isn't the problem.
Hope we all learned something about this, and I want to thank you all once again for your advice on this matter.
Thanks a lot, happy tinkering on them Dodges,
Rob C.
|
Dakota Bob
GenII
3/23/2002
08:59:37
| RE: acceleration hesitation!!!
IP: Logged
Message:
Rob glad to hear you got it fixed and that it wasn't any thing major.
Bob
Cincinnati
Jet chip stage 1 JBA Headers,19# fule Injectors,Flow master 40s Auto Lite 3923 K/N Chrome Filter 180 T Stat ,TPS adjusment,Flometrics throttle body
|
joe
Dodge Dakota
JOIN HERE
4/07/2003
20:34:39
| RE: acceleration hesitation!!!
IP: Logged
Message:
Refer to Snap On Fast Track Trouble Shooter Chry. ref C049. The problem you all speak about is listed and a simple repair to the distributor will usually remedy your problem. It refers to distributor reindexing on 92-97 3.9,5.2 and 93-97 5.9liter MPI engines. It shows how to make a home made tool out of an old rotor and a piece of welding rod to reindex the dist.If you don't have acess to this bulliton e-mail me and I will copy and send it to you. Good Luck .
|
vern
Dodge Dakota
JOIN HERE
4/08/2003
07:10:58
| RE: acceleration hesitation!!!
IP: Logged
Message:
joe- i,d be interested in this info.you can e mail me at steve197627@yahoo.com this is my sons e mail address or fax me at [207]738-3194 if you can get through because someone is on line most of the time.
thank-you
vern
|
Deep Purple
Gen III
4/08/2003
07:47:35
| RE: acceleration hesitation!!!
IP: Logged
Message:
Joe, if you could fax that to me as well, 606-920-7630. I'm interested in trying it on a truck. Thanks.
|
buddy
Dodge Dakota
JOIN HERE
4/10/2004
23:47:10
| RE: acceleration hesitation!!!
IP: Logged
Message:
JOE I WOULD LIKE TO HAVE THIS INFO ALSO THANKS MUCH
|
george
Dodge Dakota
JOIN HERE
4/10/2004
23:54:02
| RE: acceleration hesitation!!!
IP: Logged
Message:
joe send me this info to thanks.
|
cjski
Dodge Dakota
JOIN HERE
4/11/2004
14:54:12
| RE: acceleration hesitation!!!
IP: Logged
Message:
joe, fax me also please, i'd appreciate it...
thanks,chris
909.679.6918
|
cjski
Dodge Dakota
JOIN HERE
4/11/2004
14:55:07
| RE: acceleration hesitation!!!
IP: Logged
Message:
oh, never mind joe, i have a 2001...
|
srsmith40
Dodge Dakota
JOIN HERE
5/08/2007
08:52:04
| RE: acceleration hesitation!!!
IP: Logged
Message:
I'm interested in this info on about the
Snap On Fast Track Trouble Shooter Chry. ref C049. Please email me the bulletin. Thanks
|
lmao
Dodge Dakota
JOIN HERE
5/08/2007
09:30:40
| RE: acceleration hesitation!!!
IP: Logged
Message:
did you check the date of that post?
it's over 4 years old
i highly doubt you'll get a response
|
jake
Dodge Dakota
JOIN HERE
6/13/2010
11:12:14
| RE: acceleration hesitation!!!
IP: Logged
Message:
my dodge dakota 2.5 is back firing and i place the coil,plugs,plug wires,muffler and it is still back firing
|
Les Robertson
Dodge Dakota
JOIN HERE
10/01/2012
18:49:32
| RE: acceleration hesitation!!!
IP: Logged
Message:
Have 89 Dakota convertible with automatic no A/C.
2wd. After the engine warms up there is a bit of a
hesitation when I step on it around 1000 to 1500
rpm. New fuel filter, plugs, rotor and distributor
cap. I have not replaced plug wires. It runs fine
when cold...any ideas. ??? email robylw@telus.net
Les Robertson
|
daddio
Dodge Dakota
JOIN HERE
10/02/2012
13:09:30
| RE: acceleration hesitation!!!
IP: Logged
Message:
If it has an EGR, and I believe that year does, that is what's probably causing the hesitation. Check for codes before you just start throwing money and parts at it.
|
Chumley
Dodge Dakota
JOIN HERE
10/02/2012
16:38:58
|  RE: acceleration hesitation!!!
IP: Logged
Message:
#2 spark plug wire is bad.
|
| | P 1 Next Page>> |
