Cold start and running problems

Tiny
RAPTORBAHRAIN
  • MEMBER
  • 2009 DODGE CHARGER
  • 3.5L
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 30,000 MILES
Hello,

I have the car listed above RWD. I've had a problem since the end of 2018 that isn't getting diagnosed; in the morning upon cold start when I drive if I press the gas pedal half way down the power cuts off and then comes back on again and it starts running this happens for the first five to seven minutes of drive every time I let go of gas pedal and then press it half way down I starts doing it again but after five to seven minutes of running the car becomes normal and is not as bad for the rest of the day running but after leaving it parked for about four to five hours the problem reappears but not as bad as it's in the morning cold start. I've even changed the fuel pumps plus throttle body, fuel pump relay in fuse box but still the problem persists and I've run out of options there is no check engine light and the guy working on my car says he took it to several diagnostic scanner places where they did live scan and looked for stored codes but they didn’t find anything

I’m beginning to suspect intake air temperature sensor I cleaned it but no difference can buying a new IAT sensor fix my problem?

I'll appreciate any help about my car's problem, I’m in a though financial spot.

Thank you
Thursday, June 27th, 2019 AT 7:19 AM

11 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 47,602 POSTS
Hello,

I would swap out the engine coolant sensor. The diagram below shows the location. They get weak and do not send a strong/correct reading. Check out the diagrams (below). Please let us know what you find. We are interested to see what it is.
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Saturday, June 29th, 2019 AT 6:27 PM
Tiny
RAPTORBAHRAIN
  • MEMBER
  • 9 POSTS
I got the sensors tested they’re working fine, Didn’t get the o2 sensors tested but used my own basic scanner and the voltage o2 sensors showing in normal range. I’m out of option, any suggestion is welcomed of what I should test next?
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Thursday, July 4th, 2019 AT 10:16 AM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 47,602 POSTS
Can you confirm the car has 30,000 on it?
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Thursday, July 4th, 2019 AT 1:26 PM
Tiny
RAPTORBAHRAIN
  • MEMBER
  • 9 POSTS
28,000 miles (45,000 km) but it is stop and go city traffic though.
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Thursday, July 4th, 2019 AT 3:34 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 47,602 POSTS
To confirm there are no codes? If not I would try to service the throttle bore start by disconnecting the battery. Can I ask how you tested the engine coolant sensor?

https://www.2carpros.com/articles/throttle-actuator-service

Please run down this guide and report back.
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Friday, July 5th, 2019 AT 10:47 AM
Tiny
RAPTORBAHRAIN
  • MEMBER
  • 9 POSTS
First the guy with an Autel device tested it and then I used my basic scanner. I was told that it should be close to the ambient temperature and it was 4 degree more than ambient temperature when I tested it. Also the same guy who changed my fuel pumps also switched changed my throttle body too.
My throttle body is new so I don’t have to do the service for which you provided the instructions right?
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Friday, July 5th, 2019 AT 11:18 AM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 47,602 POSTS
Correct, can I ask what octain fuel do you use?
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Friday, July 5th, 2019 AT 1:02 PM
Tiny
RAPTORBAHRAIN
  • MEMBER
  • 9 POSTS
91 octane that’s the highest octane available where I live.
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Friday, July 5th, 2019 AT 4:47 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 47,602 POSTS
It sounds like the PCM is bad or you have a shorting throttle pedal sensor or throttle body. Can you have the guy with the scanner check the readout of each while you push the throttle down? If okay I would do the coolant sensor and if that doesn't help swap out the PCM. Here is are guides and instructions below. Check out the diagrams (below). Please let us know what you find. We are interested to see what it is.
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Sunday, July 7th, 2019 AT 12:52 PM
Tiny
RAPTORBAHRAIN
  • MEMBER
  • 9 POSTS
I took a junk yard PCM it didn’t help problem remained same returned it and put back my original
I tried something and it’s much better now not completely but better than before. I ran full synthetic motor oil and now it’s cutting power only for the first few seconds of a cold drive instead of the first 5 minutes.
Does this mean there’s a sensor in the engine bay that got cleaned by the synthetic motor oil but still is faulty?
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Friday, July 12th, 2019 AT 7:32 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 47,602 POSTS
This could be because the camshaft actuator is worn out causing the problems which can be accompanied by engine noise. Can you please shoot a quick video with your phone so we can hear the noise? That would be great. You can upload it here with your response.
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Saturday, July 13th, 2019 AT 12:44 PM

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