Hesitates when pulling away.

[Kentish]

My 318Ti hesitates slightly when pulling away from a standing start but is OK once moving.

Any idea what this could be?

I was thinking perhaps injectors may need cleaning or refurb but if that was so, you would usually have hesitation at any time when you try to accelerate, so maybe it isn't that either??

Fuel pressure regulator perhaps?

[Kentish]

Originally Posted by Kentish

My 318Ti hesitates slightly when pulling away from a standing start but is OK once moving.

Any idea what this could be?

I was thinking perhaps injectors may need cleaning or refurb but if that was so, you would usually have hesitation at any time when you try to accelerate, so maybe it isn't that either??

Fuel pressure regulator perhaps?

Has anyone fitted an FSE power boost fuel pressure regulator and if so was it any good?

[DustenT]

Originally Posted by Kentish

Has anyone fitted an FSE power boost fuel pressure regulator and if so was it any good?

No need for a fuel pressure regualtor, unless you don't think the factory one is doing it's job.

As always.....DO YOU HAVE A CEL?

[aceyx]

Auto / Manual?

[Kentish]

Thanks for replies

It's a manual and I'm not sure what is meant by CEL?

[stormos]

check engine light

[Kentish]

Ah, of course and I should have known (my Pontiac has one) but I think it for the US market only. Pretty sure my Ti doesn't have one.

Anyway, no dash lights show. This hesitation is only slight and you can feel it only when pulling away but I have noticed it does happen very very slightly when you feather the gas pedal whilst on the highway. Mileage is 98k now so I have a feeling my injectors may need the chemical and ultrasonic cleaning.

I'll get them done before too long.

Anyone know what they are like to remove and what kind of pressure the EFi runs at, also any special tools required?

[DustenT]

Originally Posted by Kentish

Ah, of course and I should have known (my Pontiac has one) but I think it for the US market only. Pretty sure my Ti doesn't have one.

Anyway, no dash lights show. This hesitation is only slight and you can feel it only when pulling away but I have noticed it does happen very very slightly when you feather the gas pedal whilst on the highway. Mileage is 98k now so I have a feeling my injectors may need the chemical and ultrasonic cleaning.

I'll get them done before too long.

Anyone know what they are like to remove and what kind of pressure the EFi runs at, also any special tools required?

The fuel injectors are easy to remove. Relieve pressure in the fuel system (they is a release valve on the fuel rail, press it down with a rag over it). Unbolt 2 10mm bolts that hold the fuel rail in place. Unbolt the 2 banjo bolts that hold the fuel lines onto the rail. Gently rock the fuel rail/injector assembly back and forth until the injectors are free. You might want to order some new injector O-rings from the dealership while you are at it. The are about $3/piece (you need 4).

When reinstalling the injectors, apply a small amount of motor oil to the O-rings. Get the injectors lined up with the holes in the intake manifold and GENTLY tap them into place. I use a small rubber mallet for this. Then simply bolt the 2 10mm bolts back on and hook up the fuel lines again.

[Kentish]

Thanks for the guidance, I'll print it off and keep for when I replace them.

Sounds like it is those doesn't it?

[aceyx]

Before we get into that, is this a new problem?
At what RPM are you engaging the clutch?

[Kentish]

Originally Posted by aceyx

Before we get into that, is this a new problem?
At what RPM are you engaging the clutch?

I'm not sure what revs really, I bring in the clutch at the same time as depressing the gas pedal so it's kinda variable.

Maybe I should bring the revs up and then dump the clutch more?

I have noticed the ACS+T does dumb down the responsiveness when pulling away so I switch it off when the roads are dry.

I also have this very slight hesitation whilst on the highway, it's noticable but not much. If you freewheel at say 60mph for a moment and then press the gas you feel a slight hesitation. This is why I thought it appears like it could be the injectors.