High Fuel Pressure? Leaky Injector? Or something else.

[vtl]

I purchased the car about 10,000 miles ago. The previous owner, a friend that didn't take care of the car, said he installed cheap aftermarket spark plugs in the car shortly before I bought it from him. How would your turbo behave with aftermarket spark plugs?

I was getting some sort of hesitation under the load, especially in hot days (90+). Not quite misfires, hesitation that is.

[JohnnyBee323]

I purchased the car about 10,000 miles ago. The previous owner, a friend that didn't take care of the car, said he installed cheap aftermarket spark plugs in the car shortly before I bought it from him. How would your turbo behave with aftermarket spark plugs?

I was getting some sort of hesitation under the load, especially in hot days (90+). Not quite misfires, hesitation that is.

Interesting. Correction. my friend informed me he replaced the ignition coils just before he sold me the car (he thinks from Bosch), and said he did not replace the spark plugs but they were replaced at 80k when he bought the car.

[vtl]

Take them out, check what model is the plugs and how they feel, install back, cleaning the contacts and torquing to the spec.

Good ones are FR7DPP+ if I remember correctly.

[JohnnyBee323]

Take them out, check what model is the plugs and how they feel, install back, cleaning the contacts and torquing to the spec.

Good ones are FR7DPP+ if I remember correctly.

Thank you. I will try that out. Any other plugs you recommend besides the Bosch ones?

[vtl]

Thank you. I will try that out. Any other plugs you recommend besides the Bosch ones?

I'm not sure how much you can save on aftermarket plugs? OE set is like $50 or under, they last for well over 50k miles.

Same with the oil: it's cost is completely diluted in the cost of gas consumed during oil change interval.

I still have all original coil packs at 14 years and 206k miles... Good ground, proper torque, that's it.

[JohnnyBee323]

Thank you. I will try that out. Any other plugs you recommend besides the Bosch ones?

I'm not sure how much you can save on aftermarket plugs? OE set is like $50 or under, they last for well over 50k miles.

Same with the oil: it's cost is completely diluted in the cost of gas consumed during oil change interval.

I still have all original coil packs at 14 years and 206k miles... Good ground, proper torque, that's it.

Right. That's what I am wondering, should I get the OE plugs or the Bosch FR7DPP+ you recommended?

[vtl]

Right. That's what I am wondering, should I get the OE plugs or the Bosch FR7DPP+ you recommended?

OE. I buy OE as much as I can afford =)

[JohnnyBee323]

Right. That's what I am wondering, should I get the OE plugs or the Bosch FR7DPP+ you recommended?

OE. I buy OE as much as I can afford =)

I gotta say, the fuel trim is looking much better and the green check mark light came on on my scanner for the first time. Don’t want to breath a sigh of relief just yet, it seems the engine almost wants to surge on startup still, but it doesn’t. I’m hoping the the new MAF sensor is reprogramming the computer, and will continue to improve with more cold starts, as it seems to be doing. We will see. But much better so far.

See below. Photo of the scan tool at idle just after I parked the car after driving an hour 40 miles on highway and backgrounds to work.

[vtl]

Look perfect. Trim adaptations will float a bit due to EVAP system purging the air from fuel tank, but that's normal for US/Canada vehicles.

[vtl]

Hard start ups can be caused by worn/stuck piston compression rings. Engine builds compression for longer than it should, thus it rejects to fire for a bit until the compression reaches its level. Try to soak rings overnight in Seafoam or similar fluids. I recall now I did this 2 or 3 times in the first years after I purchased the car. I helps to remove the passenger side wheel and turn the crankshaft +/- 15 degrees from time to time to agitate the rings. Don't forget to change oil afterwards.

Switching to a thicker quality oil will also help. I use Red Line 10w40 for a few years, very happy with it. It does not turn to sludge, does not lacquer the inner surfaces and washes the engine.