Runnability issue

So I have put about 100 miles on the Passat so far, I am having a runnabilty issue the car looses power above 2000 rpms and dose not want to rev past 3000 rpm in gear.


I have started checking some things on the car, I have installed a factory air box with brand new air filter, new fuel filter, the in tank pump is making 15 psi, I have checked the cam and looks to be in good condition. The timing marks line up, I was told the car has a stage 2 Malone tune, the car has a egr delete and MAF delete and a manual trans swap. The car has no check engine light on, and has no codes.



From the log file the intake MAP specified and MAP actual follow each other pretty close, it dose not mater if the engine is warm or cold, and I don't notice a lot of smoke on start up or driving. From what I have read with the MAF delete the car uses the map sensor to determine fuel demand.



I plan on taking off the down pipe to see if that helps, and I am going to check fuel pressure at the tandem pump. What should I look at, what am I over looking? Since the MAP specified and actual are close dose that rule out a big boost leak?

fuel any good, Cat plugged?

Check the torsion values, and one other thing could be fuel aeration, which you would check for by putting a clear hose in the fuel return and letting it run.

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I removed the downpipe from the turbo and the car ran the same. I replaced the fuel filter to see if that would help and no change there.

I will check for aeration in the return line next.

Torsion value was between 0-1, is it possible to have the cam sprocket off on the camshaft a little bit? Would it be worth while to loosen the 3 bolts on the cam and try adjusting it either direction to see if that helps runabilty?

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Probably wont help with the running issue, but it looks better with different wheel and a wash.

So I spent some time with the fuel system today, I had a second tandem pump from a bew and got a rebuild kit for it. Both spring where broke in the bew pump, so I put new springs and seals in it. I pulled the charge air tube and was going to check fuel volume, looked at the fuel lines and said to myself those don't look right. The feed and return fuel lines between the filter and tandem pump where switched. So I switched the fuel lines took it for a test drive, runs great now.

Ext290 said:

So I spent some time with the fuel system today, I had a second tandem pump from a bew and got a rebuild kit for it. Both spring where broke in the bew pump, so I put new springs and seals in it. I pulled the charge air tube and was going to check fuel volume, looked at the fuel lines and said to myself those don't look right. The feed and return fuel lines between the filter and tandem pump where switched. So I switched the fuel lines took it for a test drive, runs great now.

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Glad it was something simple! Interestingly enough,I was working on my car and just saw there was a tsb for that. I didn't know that, but it's another thing to stick under my belt.

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Did you get the car cheap because it was running poorly?
Good job figuring it out.

Yes, was told it had a bad engine. Previous owner had replaced the turbo feed line, he told me it blew on the freeway when driving. Motor sounded terrible like a bad rod bearing, ended being bad fuel in it, drained it and motor got quite but was low on power. In my process of trying to figure out the motor noise I pulled the pan and found it had a balance shaft delete already. Pulled the valve cover to check cam and injector lash, the injectors where 2 to 2.5 turns out.

But I bought it for $1000 with a manual swap done to it, and stage 2 tune on it. Didn't have much history on what was done to it or why. I had planned on putting a new motor in it but this one runs good now and dosent seem to be using any fluids. So I will drive it and see how it does

Ext290 said:

Yes, was told it had a bad engine. Previous owner had replaced the turbo feed line, he told me it blew on the freeway when driving. Motor sounded terrible like a bad rod bearing, ended being bad fuel in it, drained it and motor got quite but was low on power. In my process of trying to figure out the motor noise I pulled the pan and found it had a balance shaft delete already. Pulled the valve cover to check cam and injector lash, the injectors where 2 to 2.5 turns out.

But I bought it for $1000 with a manual swap done to it, and stage 2 tune on it. Didn't have much history on what was done to it or why. I had planned on putting a new motor in it but this one runs good now and dosent seem to be using any fluids. So I will drive it and see how it does

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Wow, with a manual swap too!

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The previous owner was selling it as a rare factory manual trans car, I knew better from the forum. I figured even if I needed a different motor the purchase price wasn't bad.

I put a bew glow plug harness on today, will see if this helps with the check engine light. Had to move the coolant pipe over a little but seems to fit

N75 valve can cause similar symptoms.