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Delay when accellerating from standstill
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=5&t=33106		 Page 1 of 1
Author:  Sonix [ Sat Jun 07, 2008 4:39 am ]
Post subject:  Delay when accellerating from standstill
Just a quick question ...
I've noticed that my CRD has a "let's call it delay", when I pull away from the stationary position.
Almost as if it's first thinking whether it should accelerate properly or not ...
I've also noticed the following: ... while the Jeep is stationary, and in neutral ... when you quickly push down on the accelerator, the engine also has a delay of about half a second, before it starts to rev up ...
With my Isuzu TD, this was not the case ...when you push down on the accellerator, you would notice the response on the engine IMMEDIATELY ... same when pulling away from stationary position ...

Is this just bad turbo lag, or is it maybe just a delay, caused in the electronics of the fuel system? Maybe this is normal for all the Jeeps?
Author:  STATELINE [ Sat Jun 07, 2008 7:16 am ]
Post subject: 
this is just a trait of the "fly by wire" common rail injection used on the jeep, the newer common rail dodges do the same thing. the older ones, including your isuzu, used an actual throttle linkage or cable = instant rev
Author:  Joe Romas [ Sat Jun 07, 2008 7:37 am ]
Post subject:  "seems like forever"
The pause when in neutral is as stateline says a "drive by wire" thing.

However a "seems like forever" pause when your pulling out into traffic from a stop is one symptom of air in the fuel :cry: Mine had this symptom intermittently from the beginning and it could lead to in a dangerous situation :shock: A lift pump took care of it :lol: These things run really well when they have the proper amount of fuel to the presssure pump :D I no longer have what is incorrectly called "turbo lag". One of the features of our Garret VGT turbo's is reduce/eliminate turbo lag :wink:
Author:  blake1827 [ Sat Jun 07, 2008 4:09 pm ]
Post subject: 
I noticed this same problem when I plugged in the MAF the last time I took it to the dealer, maybe try unhooking the Mass Air Flow sensor in the airbox and see if you notice a difference.
Author:  flash7210 [ Sun Jun 08, 2008 2:33 pm ]
Post subject: 
Over on one of the Dodge Caliber forumz (my wife drives a Caliber) there
was a thread about how to re-program throttle response.

Sorry I cant find it anymore but it basically involved cycling the key a few
times without starting, then slowly pressing the gas pedal to the floor and
then slowly releasing it. About 30 seconds going down, and 30 back up, 1
min total.

Dont know if the same procedure would apply to the CRD, but both ARE
drive-by-wire and made by Chrysler.

Then again, simply disconnecting the battery might do the same thing.
Author:  Sir Sam [ Sun Jun 08, 2008 2:57 pm ]
Post subject: 
flash7210 wrote:
Over on one of the Dodge Caliber forumz (my wife drives a Caliber) there
was a thread about how to re-program throttle response.

Sorry I cant find it anymore but it basically involved cycling the key a few
times without starting, then slowly pressing the gas pedal to the floor and
then slowly releasing it. About 30 seconds going down, and 30 back up, 1
min total.

Dont know if the same procedure would apply to the CRD, but both ARE
drive-by-wire and made by Chrysler.

Then again, simply disconnecting the battery might do the same thing.


I very highly doubt anything like that works on our bosch ECU.
Author:  DarbyWalters [ Sun Jun 08, 2008 5:07 pm ]
Post subject: 
Unplugging the MAF will remedy the delay as long as it is not from air-in-fuel. That is why (one of the main reasons) so many here have installed the SEGR.
Author:  Uffe [ Mon Jun 09, 2008 3:49 am ]
Post subject: 
I doubt Sonix has a MAF at all, I didn't have one on my 03 CRD. I think this is a case of turbo lag combined with a slipping automatic transmission. It's supposed to be slow the first blinks of an eye, then all hell breaks loose :)
Author:  CATCRD [ Wed Jun 11, 2008 12:08 am ]
Post subject:  Re: Delay when accellerating from standstill
Sonix wrote:
Just a quick question ...
I've noticed that my CRD has a "let's call it delay", when I pull away from the stationary position.
Almost as if it's first thinking whether it should accelerate properly or not ...
I've also noticed the following: ... while the Jeep is stationary, and in neutral ... when you quickly push down on the accelerator, the engine also has a delay of about half a second, before it starts to rev up ...
With my Isuzu TD, this was not the case ...when you push down on the accellerator, you would notice the response on the engine IMMEDIATELY ... same when pulling away from stationary position ...

Is this just bad turbo lag, or is it maybe just a delay, caused in the electronics of the fuel system? Maybe this is normal for all the Jeeps?


The delay is partly the fault of normal turbo lag, and mostly the fault of modern emissions programming that does fuel/air ratio controlling (FARC). The computer won't inject a ton of fuel off the line until it senses that there is enough air (boost pressure) to combust it without visible smoke, even though there is more power to be had by dumping it in. Also, the relatively low compression ratio (for a diesel) comes into play in reducing off boost power. Ours is something like 17:1, while diesels of days past could have 21 to 22:1.
Author:  Zonie [ Wed Jun 11, 2008 7:54 am ]
Post subject: 
The brand and condition of the air filter you use also has a bearing on how much/little
your Libby hesitates off the line! I noticed a difference when I changed from the OEM
to a Wix and an even bigger difference when I went to the AMSOIL Ea034. It had been
hesitating more over the last few days, so I took the compressed air to it and hosed out
a few bugs and a lot of dust and that was all it took!
Author:  Topan [ Fri Jun 13, 2008 11:33 am ]
Post subject:  Re: "seems like forever"
Joe Romas wrote:
The pause when in neutral is as stateline says a "drive by wire" thing.

However a "seems like forever" pause when your pulling out into traffic from a stop is one symptom of air in the fuel :cry: Mine had this symptom intermittently from the beginning and it could lead to in a dangerous situation :shock: A lift pump took care of it :lol: These things run really well when they have the proper amount of fuel to the presssure pump :D I no longer have what is incorrectly called "turbo lag". One of the features of our Garret VGT turbo's is reduce/eliminate turbo lag :wink:


Hi,
I have this problem on my '05 CRD in Switzerland and it drives me nuts. You mentione that a "lift pump" solves the problem. Can you explain what it is. If you have any specs and brands of the pump, i'll go straight to the dealer to buy one .
Many thanks
Topan
Author:  Tinman [ Fri Jun 13, 2008 12:32 pm ]
Post subject: 
I believe CATCRD hit the nail on the head. Basically is comes under torque management programing. Most diesels nowdays are programed this way for emmissions and to easy strain on the drive train. It will defuel during shifts too. The retarded injection timing (emission again) and, of course, turbo lag are part of it too. There are some programers for the truck market that modify TQ manganment and make a world of difference. I have a Smarty for my 06 and it has 4 TQ Man. programs. Mild is all I've tried and it gives you the throttle response of a gasser. Very nice. Makes it into a different truck. It has a price though, smoke. If you punch it from a stop, you'll get a nice lcloud of off boost smoke. This what the manufactorer doesn't want and therefore fuels slowly at first. The Wild TQ Management on the Smarty is no TQ man. and is a race only kinda thing. It can destroy even the best tranny, but boy, I bet it'd be fun to drive.

Sir Sam: The key on cycle, depress the acclerator trick is a way to "re-set" the TPS in some chyrsler vehicles. It will only help if the TPS is off. The correct way to re-set a TPS is to check and make sure the voltage is correct and re-set accordingly.
Author:  dgeist [ Fri Jun 13, 2008 1:47 pm ]
Post subject:  Re: "seems like forever"
Topan wrote:
Joe Romas wrote:
The pause when in neutral is as stateline says a "drive by wire" thing.

However a "seems like forever" pause when your pulling out into traffic from a stop is one symptom of air in the fuel :cry: Mine had this symptom intermittently from the beginning and it could lead to in a dangerous situation :shock: A lift pump took care of it :lol: These things run really well when they have the proper amount of fuel to the presssure pump :D I no longer have what is incorrectly called "turbo lag". One of the features of our Garret VGT turbo's is reduce/eliminate turbo lag :wink:


Hi,
I have this problem on my '05 CRD in Switzerland and it drives me nuts. You mentione that a "lift pump" solves the problem. Can you explain what it is. If you have any specs and brands of the pump, i'll go straight to the dealer to buy one .
Many thanks
Topan


Assuming the e-spec wiring is the same as the US CRDs, the in-tank unit from a Dodge Ram Cummins pickup-truck is nearly a direct swap for the kj's pump-less fuel gauge unit. (2005 RAM2500/3500 , I think, but more info is available in the "it's 10PM..." thread). After that, all you need to is add power and ground to the harness that goes from under the left rear passenger seat to the tank. Chrysler was nice enough to include the switched "key-on" power and a fuse in the body wiring from the factory.

http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?t=26385

Dan
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