P2188 and hard to start when engine is hot

[Boje]

FWIW I had the exact same symptoms on my '15 GTI at about 95k (although I don't remember what the code(s) were), and it was a fuel pump issue. Had both replaced and problem hasn't recurred.

 

[LimestonegolfR]

FWIW I had the exact same symptoms on my '15 GTI at about 95k (although I don't remember what the code(s) were), and it was a fuel pump issue. Had both replaced and problem hasn't recurred.

Thanks for the reply. If the N80 valve I bought doesn’t fix the problem, I’ll probably be getting a HPFP. So you replaced both lpfp and hpfp at the same time? Did you know which one was faulty or were they both shot?

 

[dgreger13]

I'm interested to see if the N80 valve will fix it. I'm currently having this exact issue.

 

[LimestonegolfR]

I'm interested to see if the N80 valve will fix it. I'm currently having this exact issue.

I’ll be dropping the part in tomorrow night. I’ll let you know

 

[Boje]

Thanks for the reply. If the N80 valve I bought doesn’t fix the problem, I’ll probably be getting a HPFP. So you replaced both lpfp and hpfp at the same time? Did you know which one was faulty or were they both shot?

I replaced both (with OEM pumps) on the advice of my mechanic because of my mileage and because it wasn’t too costly for the labour for both at the same time. It was to do with the internals of one of the (ageing) pumps expanding when it’s hot and therefore not functioning fully enough to the the engine enough fuel to start. I’m afraid I can’t remember the specifics but can call him tomorrow and find out for ya.

 

[S3 Freak]

Interesting topic, I'm also having the same problem, my car starts normally from a cold start but as soon as I start from cold and switch off it refuses to start again. Have to crank couple times and give it some throttle. After it starts I can get a strong fuel smell.

I then fitted a catch can and the starting issue went away....always started on the turn hot or cold.

I then tried to find the problem and fitted my stock pcv which led me to the lower oil solenoid which sits in the aluminum oil pan... As soon as I disconnect the solenoid the car starts on the turn hot or cold.... Plug it in then it cranks couple times before starting. Replaced the solenoid but still now and then the car battles to start... definitely less frequently.

I have a spare hpfp will try fitting it and see if the problem goes away.

 

[LimestonegolfR]

Interesting topic, I'm also having the same problem, my car starts normally from a cold start but as soon as I start from cold and switch off it refuses to start again. Have to crank couple times and give it some throttle. After it starts I can get a strong fuel smell.

I then fitted a catch can and the starting issue went away....always started on the turn hot or cold.

I then tried to find the problem and fitted my stock pcv which led me to the lower oil solenoid which sits in the aluminum oil pan... As soon as I disconnect the solenoid the car starts on the turn hot or cold.... Plug it in then it cranks couple times before starting. Replaced the solenoid but still now and then the car battles to start... definitely less frequently.

I have a spare hpfp will try fitting it and see if the problem goes away.

Let me know if the hpfp resolves the issue. Seems that a lot of folks are having this issue. I’ll let you guys know tonight if the purge valve is the culprit, I’ll be replacing it after work.

 

[Boje]

I replaced both (with OEM pumps) on the advice of my mechanic because of my mileage and because it wasn’t too costly for the labour for both at the same time. It was to do with the internals of one of the (ageing) pumps expanding when it’s hot and therefore not functioning fully enough to the the engine enough fuel to start. I’m afraid I can’t remember the specifics but can call him tomorrow and find out for ya.

Okay so I finally got hold of the mechanic and he said the issue in my car was that the LPFP was failing, although we replaced both to be sure (I was at about 95k miles). He said that it was to do with parts inside the LPFP's electric motor expanding when the car was hot, and not functioning properly as a result (when the car was cold, it would start fine).

 

[LimestonegolfR]

Okay so I finally got hold of the mechanic and he said the issue in my car was that the LPFP was failing, although we replaced both to be sure (I was at about 95k miles). He said that it was to do with parts inside the LPFP's electric motor expanding when the car was hot, and not functioning properly as a result (when the car was cold, it would start fine).

I’ll be looking at hpfp/lpfp next. The New purge valve didn’t change a thing!

 

[Johnemacc]

3rd picture, plug on the left looks like its cracked. N80 valve aint going to change a thing

 

[LimestonegolfR]

3rd picture, plug on the left looks like its cracked. N80 valve aint going to change a thing

At the top? Dog hair

 

[LimestonegolfR]

So after installing a new HPFP and taking it for a spin to get it to operating temp, the car is starting like a champ every time thereafter! Huge relief and I’m “pumped” that I was able to install it myself to save some money. thanks for steering me in the right direction!

 

[RallyCoop]

I am having the same problem. Hard start after the engine is hot. It also idles rough when the engine is hot. The fuels trims a in the range of negative 40 to 60. Otherwise the trims are normal before the engine heats up. The dealer did a carbon clean, new plugs, one new coil, new B1S1 oxygen sensor, two new injectors and nothing has changed. I also noticed the LPFP is delivering 11 bars of pressure at idle and it does not change over the range of engine load. It is producing the maximum output pressure regardless of engine load. The service data states that pressure regulator built into the LPFP is defective if the output pressure is too high.
If maximum pressure is sent to the HPFP at idle, the regulator on the HPFP may not be able to dial back the final pressure going into the injectors resulting in negative fuel trims and misfire at idle. I suspect the reason it does not misfire off idle is because the engine is consuming more fuel and the overpressure is less significant under load. I will be installing the LPFP today and will advise if it's corrected.

 

[git443]

I am having the same problem. Hard start after the engine is hot. It also idles rough when the engine is hot. The fuels trims a in the range of negative 40 to 60. Otherwise the trims are normal before the engine heats up. The dealer did a carbon clean, new plugs, one new coil, new B1S1 oxygen sensor and nothing has changed. I also noticed the LPFP is delivering 11 bars of pressure at idle and it does not change over the range of engine load. It is producing the maximum output pressure regardless of engine load. The service data states that pressure regulator built into the LPFP is defective if the output pressure is too high.
If maximum pressure is sent to the HPFP at idle, the regulator on the HPFP may not be able to dial back the final pressure going into the injectors resulting in negative fuel trims and misfire at idle. I suspect the reason it does not misfire off idle is because the engine is consuming more fuel and the overpressure is less significant under load. I will be installing the LPFP today and will advise if it's corrected.

You have a similar issue as me. Read my post here and follow till the latest update: https://www.vwvortex.com/threads/hard-starting-when-engine-is-warm.9499266/post-115921463

Take note, your car doesn't have a low pressure fuel sensor, so the readings you see are false. I would ignore it. You can only read high pressure fuel.

 

[RallyCoop]

You have a similar issue as me. Read my post here and follow till the latest update: https://www.vwvortex.com/threads/hard-starting-when-engine-is-warm.9499266/post-115921463

Take note, your car doesn't have a low pressure fuel sensor, so the readings you see are false. I would ignore it. You can only read high pressure fuel.

Thanks for the reply. I replaced the LPFP and no change. You are correct about the reading being false. I am going after the HPFP next.