× Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!

Erratic LTFT?

  • Snakehips
  • Topic Author
  • Offline
  • New Member
  • New Member
More
30 Nov 2022 06:00 #59023 by Snakehips
Erratic LTFT? was created by Snakehips
Wonder if anyone could help before I lose the will to live with this issue.

I have a Peugeot 207 1.4 petrol 16v done about 125,000 miles, the car starts perfectly every time, but when the engine is cold I have to sit there for at least 5 mins until the engine warms up, then I can drive off.

If I don’t let the engine warm up, I drive off and the engine is sluggish, pedal to floor and no movement, then it will all of a sudden kick in, if I stop at junction the engine will cut out.

When at Idle also sounds rough until it has warmed up.

I have changed the following:
Spark plugs
Coil pack
MAP sensor
Camshaft sensor
Variable valve oil solenoid sensor
I have also checked for a compression leak by spraying cold start spray around the vacuum hoses, intake manifold and throttle body area and can’t see any rev changes.

I have no engine management light on and no error codes when scanned.

I have attached a live data scan of a short journey which shows erratic LTFT is this normal?

Anyone else come across this problem before?
Attachments:

Please Log in or Create an account to join the conversation.

More
30 Nov 2022 18:41 #59025 by Tutti57
Replied by Tutti57 on topic Erratic LTFT?
It's hard to tell from the graph, without having the rpms, but I'd guess that the ltft goes high when it's at low roms, like idle, then goes down when you give it some revs. That would be a classic vacuum leak. From the sounds of the cold start running too, possibly the intake manifold gasket.

Does this car have a MAF sensor or just a MAP? My theory falls to pieces if it's just a MAP...

Please Log in or Create an account to join the conversation.

  • Snakehips
  • Topic Author
  • Offline
  • New Member
  • New Member
More
01 Dec 2022 07:41 #59032 by Snakehips
Replied by Snakehips on topic Erratic LTFT?
Hi thanks for your reply, I have submitted the same graph taking away speed and have added revs and MAP sensor. Does that help?
Attachments:

Please Log in or Create an account to join the conversation.

More
01 Dec 2022 12:06 #59036 by Tutti57
Replied by Tutti57 on topic Erratic LTFT?
So does it only have the MAP sensor and no MAF? Fuel trim tests are easier to read when you are just in park or neutral, held at idle, then held at like 2500rpms, noting what is happening during those two speeds. There are other factors when you're driving around that make it more difficult to view like this, for me at least.

Please Log in or Create an account to join the conversation.

  • Snakehips
  • Topic Author
  • Offline
  • New Member
  • New Member
More
01 Dec 2022 15:47 #59039 by Snakehips
Replied by Snakehips on topic Erratic LTFT?
No it doesn’t have a MAF sensor, I think they are only in diesel vehicles. I added the graph from the vehicle moving as this is when the car has the most issues.

I will run another scan as you have mentioned above, any particular sensors you’d be interested in seeing?

Please Log in or Create an account to join the conversation.

  • Snakehips
  • Topic Author
  • Offline
  • New Member
  • New Member
More
02 Dec 2022 04:12 #59048 by Snakehips
Replied by Snakehips on topic Erratic LTFT?
Does the O2S2 look right to you?

Attachments:

Please Log in or Create an account to join the conversation.

  • Not Allowed: to create new topic.
  • Not Allowed: to reply.
  • Not Allowed: to edit your message.
Time to create page: 0.332 seconds