Acceleration issues

[Jumpy Jr.]

Hi all,

I've picked up a 2000 D22 Navara for $500aud
I really got what I paid for, this poor thing has been in my garage for the last two months; replacing seals, ball joints, ripping out 3rd party wires etc.

I've now finally got her on the road and noticed that it has trouble getting up to 110kph (70mph)

Pedal to the ground, it takes about a minute to creep up from 100 to 110 (in fourth gear), then changing to fifth gear results in slowly dropping back down again until I hit 105, then I need to change back to fourth to get back to speed again.

Ultimately my question is, does this seem like the usual for an old 3.2L, 4 cyl diesel? Or is there something I should look at to hopefully restore my Ute back to her former glory?

Cheers for any advice

It's a QD32 engine

 

[Old.Tony]

It does sound like it's underpowered.

Apart from timing (which I assume is ok for the discussion), the two things needed are fuel and air in the correct quantity. It's often the air that's an issue.

Does it blow a LOT of black smoke? This would indicate there's not enough air. Potentially a blockage in the air path, looking in the bottom of the air filter box would be a good start.

Note that "air" means "clean, fresh air", so a stuck EGR valve would reduce the amount that enters the motor. With yours, you wouldn't have to worry about flow sensors so just blocking the EGR would fix that.

The fuel is almost simple. If the fuel rail pressures are ok and the injectors are clean, the correct amount will be delivered. Using Liqui Moly Diesel Purge is a great way to clean the injectors if it's just gunk on them (can't tell unless you remove them or try it).

Some cars with the Bosch VP44 fuel pump have issues but usually these pumps just die (and I believe it's a small electronic component that fails on a control board, which is annoying because a $1 part is killing a $1,000 pump). Have a look at yours, see if it's got one of these. You'd have to check fuel pressures to know if the pump wasn't delivering as expected.

 

[Jumpy Jr.]

{I made edits to this post, then accidentally reposted it so see below message}

It does sound like it's underpowered.

Apart from timing (which I assume is ok for the discussion), the two things needed are fuel and air in the correct quantity. It's often the air that's an issue.

Does it blow a LOT of black smoke? This would indicate there's not enough air. Potentially a blockage in the air path, looking in the bottom of the air filter box would be a good start.

Note that "air" means "clean, fresh air", so a stuck EGR valve would reduce the amount that enters the motor. With yours, you wouldn't have to worry about flow sensors so just blocking the EGR would fix that.

The fuel is almost simple. If the fuel rail pressures are ok and the injectors are clean, the correct amount will be delivered. Using Liqui Moly Diesel Purge is a great way to clean the injectors if it's just gunk on them (can't tell unless you remove them or try it).

Some cars with the Bosch VP44 fuel pump have issues but usually these pumps just die (and I believe it's a small electronic component that fails on a control board, which is annoying because a $1 part is killing a $1,000 pump). Have a look at yours, see if it's got one of these. You'd have to check fuel pressures to know if the pump wasn't delivering as expected.

 

[Jumpy Jr.]

Thanks for steering me in the right direction- I'll definitely check through all this when I find time (maybe not for the next few weeks)

I don't get any black smoke, but a small amount of white smoke on startup

If I find anything I'll relay it back

It does sound like it's underpowered.

Apart from timing (which I assume is ok for the discussion), the two things needed are fuel and air in the correct quantity. It's often the air that's an issue.

Does it blow a LOT of black smoke? This would indicate there's not enough air. Potentially a blockage in the air path, looking in the bottom of the air filter box would be a good start.

Note that "air" means "clean, fresh air", so a stuck EGR valve would reduce the amount that enters the motor. With yours, you wouldn't have to worry about flow sensors so just blocking the EGR would fix that.

The fuel is almost simple. If the fuel rail pressures are ok and the injectors are clean, the correct amount will be delivered. Using Liqui Moly Diesel Purge is a great way to clean the injectors if it's just gunk on them (can't tell unless you remove them or try it).

Some cars with the Bosch VP44 fuel pump have issues but usually these pumps just die (and I believe it's a small electronic component that fails on a control board, which is annoying because a $1 part is killing a $1,000 pump). Have a look at yours, see if it's got one of these. You'd have to check fuel pressures to know if the pump wasn't delivering as expected.

 

[MichaelT]

My D22 YD25 drove just like yours is (gutless) for several months until I happened to look at the MAF (Mass Air Flow) sensor, and noticed a foreign body lodged beside the sensing wires (something an insect had deposited when I had the air box off for an exptended period while I fitted a new cylinder head).
I cleaned it out with Engine Degreaser and suddenly had power I hadn't imagined possible !

 

[australianoz]

Check your cams, I've experienced this issue before. A faulty oil relief value (dodgy oil filter) ran my exhaust cams flat. You never know.