PD150 Studdering issues when high RMP.. Lift Pump issues?

Recently got a used PD150 installed installed in my car (the PD150 had about 56K miles on it)
. The PD150 never did work right since it got installed. It drives OK if you are a grandma but the moment you step on it, it start to studder and hesitates.. the higher RMP's the more it studders.... like it's missing fuel. This only happens when I try too accelerate hard... (it never does accelerate hard... a frickin prius coud beat me ). It accelerates super slowly and when it gets to high RMP's is misses like it's stalling but does not stall.. just kindda studders with interrupted acceleration .. coasts and misses ... super annoying. It has no studdering issues at all when driving it like a grandma.. it coast fine at lower RMP and accelerates slowly fine until I get to higher RPM's then studders.

The lift pump does make noise when I turn on the key for a second or two but I am not clear if it is pumping like it should.

I never had any issues starting it. It starts super well.... instantly the moment I turn the key..

I just replaced the fuel filter just in case and it did not make any changes whatsoever.... still fubar.. I have about 40K on the lift pump so I just bought another one as a my next step in the diagnostic process. It should get here by the weekend. I will put that new lift pump in and see if it makes any difference.

Also I got an (apparently) super aggressive tune and was told by my tuner that my car should smoke like a freight train with my latest tune... I cannot even see any haze back there.. (My ALH w/ RC6 and Race 520's used to smoke out the neighborhood when I stepped on it)

Could this be a Lift Pump issues? slowly failing lift pump? a lift pump which makes noise but does not pump right?

Also there are currently no CEL. I had an intermittent CEL for CTS so I ordered one of those as well. That one comes and goes but it goes a long time without reappearing.

Also the tune is MAF delete so no issues there.

Any other issues I should consider?

Tandem pump issue? no leaks there, only has 56K on it?

If the lift pump does not work in resolving the issue, I am considering next:

1- changing out the tandem pump - if that does not fix the issue then:
2- remove the injectors & changing replacing the nozzles, maybe even upgrade at the same time. if that does not work then:
3- pour about 5 gallons of gasoline inside and on top of it and burn the MOFO thing to the ground

All thought welcome.... Tnx for your help

Checed the gasket on the fuel filter? And are all the fuel lines where they should be?

Tnx for the response,

Check the gasket on the fuel filter? Yes, all good

And are all the fuel lines where they should be? Yes, all good there as well

For the heck of it, put a stock tune on it.

Is the PD lift pump wired to the ignition or ecu? The method of wiring to fuel cutoff solenoid obviously doesn't work anymore.

Did you check all obstructions?

Did you run any logs? Boost logs, MAF(if you have one installed) logs, fuel logs(ch1 and 4)?

The cam looked ok going in?

Also look at the injector balance in VCDS?

All great comments, tnx for posting....

JFettig said:

For the heck of it, put a stock tune on it.

Is the PD lift pump wired to the ignition or ecu? The method of wiring to fuel cutoff solenoid obviously doesn't work anymore.

Did you check all obstructions?

Did you run any logs? Boost logs, MAF(if you have one installed) logs, fuel logs(ch1 and 4)?

Click to expand...

I had a stock tune before excerpt MAF delete, was worst. Put a higher power, more fuel tune on.. a little better but same issues at higher RPM.

The PD lift pump is wired on a relay identical to the OEM PD 150. It gets the ECU signal and run the pump for 1 to 2 secs when I turn the key and stops. It runs a full 30 seconds when going to block 035 in basic settings -04 so we know it is wired correctly.

Yes on the obstructions, before I had an ALH in there and it pulled hard. I could not see any damaged or kinked fuel tubing... I have a fuel cooler so I will take another look at all the hoses these to make sure no kinks or other obstructions. I will also check by disconnecting the fuel hose at the filter and run the pump for 30 seconds to see how much it flows fuel... maybe it will tell me something... great idea...

Yes on running all the logs, been running all these logs and sending back and forth to my tuner. No obvious issues pointed out there... all 4 injectors are well within range and no wide variations. the tune is MAF delete so no issues there. boost logs are match the requested boost pretty close.

dieselpower04 said:

The cam looked ok going in?

Click to expand...

Cam looked great...

dieselpower04 said:

Also look at the injector balance in VCDS?

Click to expand...

Injector balance was well within range and no wide gaps.

keep em coming...

tnx

Possible bad injector harness in head? I had a car that was stuttering and vibrating, erratically with no codes. Power was ok but drove like crap. New injector harness solved it.

Ditto ^


It could also be that your car is very unhappy since you put a PD in an ALH car

PD150 has a history of leaking tandem pumps. From what I've read this is the first sign of broken pump.

Mine was leaking all over the place, putting all the rubber hoses around in danger. Do you see any fuel/oil around it?

Tnx, Is the same harness as the US PD's? http://www.idparts.com/catalog/product_info.php?products_id=2318

I want to get one but want to make sure I buy the right one. Anybody got apart number for the PD150 injector harness?

No leaks whatsoever around the tandem pump ...

So next step after the lift pump change is the injector harness... then the injector nozzles?

tnx

Pierre, i believe all the pd harnesses are the same.

Sometimes it is also needed to replace the stickers (spades or whatever the English name is) in the round connector from engine wire harness
Make sure to use gold plated ones,they can be bought from the dealer and comes crimped on a yellow cable

Problem solved... Installed new unmodified lift pump, studder gone... not as much power as my ALH but at least no studder.... little smoke too.. so I know I am getting fuel.

After my test drive, I examined the lift pump and I believe I may have identified the cause of the studder... When I first put this lift pump in, I did the "left Coast Mod" to it... i.e. added a check valve and bypass circuit in case the pump went bad ... however by looking at the green hose I have there, it clear that there is a good kink in it. Hose may have been too long. Maybe I will try taking out the kink and putting a 90 degree barbed elbow in that location. Then reinstall the pump to check....

It was caused by either a bad pump or this kink in the tubing.. .My bet is the kink...

Tnx for your help everyone

P

Ahh that's no good!

Well glad you solved it!