Bucking with initial acceleration, D-Jet |
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Bucking with initial acceleration, D-Jet |
Montreal914 |
Dec 31 2015, 06:05 PM
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#1
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Senior Member Group: Members Posts: 1,571 Joined: 8-August 10 From: Claremont, CA Member No.: 12,023 Region Association: Southern California |
I've been trying to solve an issue that makes the driving rather unpleasant (IMG:style_emoticons/default/headbang.gif)
I have a 2056 D-Jet that I daily drive. Recently I replaced the fuel filter and since then, the car has developed this behavior which I don't see why it would be related. When I put in first gear and get going, the car doesn't pick up and is bucking. As I progressively press on the pedal, it suddenly picks up and gets going normally. While it's trying to get going, I've noticed that my A/F gauge tends to go lean and out of range. Things that came to my mind: faulty throttle switch which influences the fuel delivery, hence lean. On the TPS, I checked the open/close circuit of the 2 traces with the 10 switches and everything is good. Idle switch kicks in also. I checked the resistance of the whole D-Jet harness on the 25 pin connector at the CPU as suggested by Anders and everything is within range. Replaced the points and adjusted Dwell. Fuel pressure is set at 29psi (analog gauge inline). I swapped the TPS, the CPU, the MPS, the coil without any improvement. I'm running out of ideas... (IMG:style_emoticons/default/sad.gif) Maybe someone has experienced something like this (IMG:style_emoticons/default/confused24.gif) |
Spoke |
Jan 2 2016, 10:57 PM
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#2
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Jerry Group: Members Posts: 6,986 Joined: 29-October 04 From: Allentown, PA Member No.: 3,031 Region Association: None |
Does it do this when cold and hot?
Does acceleration at higher RPMs seem ok? Did you verify the TPS is working in the circuit? Test the TPS with the following steps: 1) Remove the power (12V) to the coil. Make sure it doesn't touch anything. 2) Turn the ignition to ON but don't start the car. 3) Slowly open the throttle. You should hear the injectors fire as you open it. Firing the injectors will not dump a bunch of fuel in the intakes as the fuel pump will not be running. They will bleed off some of the fuel as the fuel pressure drops. |
Montreal914 |
Jan 3 2016, 01:07 AM
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#3
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Senior Member Group: Members Posts: 1,571 Joined: 8-August 10 From: Claremont, CA Member No.: 12,023 Region Association: Southern California |
Does it do this when cold and hot? Does acceleration at higher RPMs seem ok? Did you verify the TPS is working in the circuit? Test the TPS with the following steps: 1) Remove the power (12V) to the coil. Make sure it doesn't touch anything. 2) Turn the ignition to ON but don't start the car. 3) Slowly open the throttle. You should hear the injectors fire as you open it. Firing the injectors will not dump a bunch of fuel in the intakes as the fuel pump will not be running. They will bleed off some of the fuel as the fuel pressure drops. The engine runs very nice except at very low RPM. I have been running this engine daily for over 2 years without this issue so it's not due to it's new configuration. I tested the TPS "accelerator pump" mode 10 switches with the multi meter. I like the idea of the injector testing. I will try it for sure. I was thinking maybe I should try some injector cleaner fluid... do they work or is it BS? (IMG:style_emoticons/default/confused24.gif) I revisited my Dwell adjustment that ended up being at 50-51 which is at the limit and brought it down to 46-47 which is more in the middle of the range. It did help a little. Maybe fuel is not the right place to be looking at... (IMG:style_emoticons/default/dry.gif) I appreciate all the help (IMG:style_emoticons/default/beer.gif) |
Spoke |
Jan 3 2016, 09:33 AM
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#4
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Jerry Group: Members Posts: 6,986 Joined: 29-October 04 From: Allentown, PA Member No.: 3,031 Region Association: None |
I revisited my Dwell adjustment that ended up being at 50-51 which is at the limit and brought it down to 46-47 which is more in the middle of the range. It did help a little. Maybe fuel is not the right place to be looking at... (IMG:style_emoticons/default/dry.gif) You should dump the points. They are so neanderthal. Install electronic ignition of your choice and never worry about setting dwell again. |
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