RPMs drop at red light

[Ghost3366]

Hello,

Weather is just starting to get to a point where I can work outside without turning into an ice cube , so I will start trying some options soon the first thing I am trying is the purge valve. I noticed after I filled the gas tank it got worse, so I am thinking this is pointing to the purge valve, but maybe not. It will be the first thing I check . After I try that I will post back most likely in the next couple of weeks.

Sponsored

 

[Texstang]

I have somewhat of a similar issue. I've pinned it down to the following:

It occurs shortly after I fill up the car, but only if I fill up from less than a 1/4 tank. If I fill up from a half or 3/4, it doesn't happen. When it does occur, it's usually shortly after I've left the gas station and waiting at a red light in neutral or in 1st with the clutch depressed. The idle will drop to ~500 RPM for about half of a second, and then return to normal. The car is always at operating temperature once I get to the gas station. It may do it once or twice during that initial trip but not again unless I refill from less than a quarter tank. In most areas of the US, the vapor pressure of gasoline is regulated and refineries produce fuels with lower vapor pressure in the summer and are allowed to produce fuels with higher vapor pressure in the winter. I've noticed it noatter the season.

When I fill up, I don't "top off" after the fuel cutoff is tripped from the pump. I don't have any CELs and I don't have any related DTCs when I check using ForScan. My plugs are fairly new and were pre-gapped and checked before I installed them. It happened before I replaced them. I also don't have a rough idle when cold and never had the smoking issue some have had with the EB.

Does anyone know what to look for in ForScan? I noticed there are PIDs relating to the vapor canister, fuel tank pressure, and evap purge valve and duty cycle, but I'm not sure what to look for. I'll do some datalogging and see if I can find a pattern.

 

[Hellman109]

^^ 95% chance its the purge valve, common problem and simple fix

 

[Ghost3366]

Just wanted to give an update to this issue, if anyone else is experiencing what I did. I changed the purge valve last week and the next day filled up the gas tank. I have not driven a lot since, but so far issue has not showed up again.

 

[Tom4]

Hi guys,

actually I started have same problems with my Mustang V8 2018.

What I understand, everything I need is to change Canister Purge Valve, but can you help me find correct Part Number for my car?

My VIN 1FA6P8CF2J5152005

Many thanks for help

 

[BoostedNate]

Just wanted to give an update to this issue, if anyone else is experiencing what I did. I changed the purge valve last week and the next day filled up the gas tank. I have not driven a lot since, but so far issue has not showed up again.

I've been having this same issue and been trying to pin it down. For me it seems to happen most frequently when starting the car and AC is on max. I replaced the purge valve almost 2 years ago, along with the fuel sensor.

Sponsored