Jason25klein
Active member
2001 jetta tdi 1.9. Won't make any power. Only goes to 2000rpm and when I unplug the maf sensor it'll Rev to more. Replaced it and still the same.
Need some advice!
- Thread starter Jason25klein
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Johhny04
Veteran Member
scan your car for codes
Jason25klein
Active member
It don't have any codes
BobnOH
not-a-mechanic
No stored codes? That's unusual. The low power/limp mode thread in my signature will have some ideas. There are several things that might cause this. Try this search engine for other's experience- VW TDI Search
Jason25klein
Active member
Very I've replaced pretty much all the sensors new turbo, wastegate. Tested all the vacuum lines an they all hold pressure unhooked the exhaust. I been thinking maybe a bad ecu?
BobnOH
not-a-mechanic
Wow, some parts. ECUs rarely fail like that. Try careful troubleshooting using the Scientific Method. Could be a clogged intake. Partial removal of the EGR stuff will get you a look see. It will be nasty, needs to have an opening somewhat larger than a dime. If you don't have the VCDS device, you may want to pick one up. Or find a TDI experienced mechanic.
Jason25klein
Active member
It has a egr delete kit on it
BobnOH
not-a-mechanic
Whatever you need to do to get a look at the intake, it might be clogged. Would certainly cause that issue.
But's that's just one potential cause. I'm sure it's something simple and you'll kick yourself when you finally find the issue.
But's that's just one potential cause. I'm sure it's something simple and you'll kick yourself when you finally find the issue.
Jason25klein
Active member
I took it a reputable diesel repair shop and they also couldn't figure it out. But I'll take a look at it
BobnOH
not-a-mechanic
find a TDI experienced mechanic
oilhammer
Certified Volkswagen Nut & Vendor
OBD works, start there.
How was the EGR deleted? What software is being used?
It does NOT need an ECU.
How was the EGR deleted? What software is being used?
It does NOT need an ECU.
Jason25klein
Active member
I bought it this way. I know the guy, my knowledge he didn't use any software. I'll have to ask him
oilhammer
Certified Volkswagen Nut & Vendor
OK so the EGR has been disabled, not deleted, so your MAF is not able to work correctly. Your ECU is not getting the correct information.
It is hard to diagnose a running problem when you throw the ECU a curve ball like that.
It is hard to diagnose a running problem when you throw the ECU a curve ball like that.
Jason25klein
Active member
I just talked to the guy he said it didn't run before he he disabled it either. He Disabled it case the cooler hooked to it was leaking
Does it smoke? Has the cat been removed or still there?
Did you change out the filters?
I would say do basic maintenance first and if the problem is still there then keep looking, clogged cat, intake, etc, there can be many things
keep us updated
Did you change out the filters?
I would say do basic maintenance first and if the problem is still there then keep looking, clogged cat, intake, etc, there can be many things
keep us updated
Jason25klein
Active member
I unhooked the exhaust. All new filters it doesn't smoke at all. Idles a d starts like new
And have you taken a look at the intake?
You mentioned if you remove the MAF it will rev to more, but you've replaced it and it goes back to the same?
If that was my car I'd definitely have a look at someone who could look at my ECU for cheap (no $400 tunes)
Not too long ago a friend of mine had similar issues, however his car being a '99 it couldn't be mapped thru OBD, so we opened the ECU to check if someone has mapped it before and it was completely stock. But he got a used ECU anyway and the car ran fine after that, no idea what was wrong with the old one though
Jason25klein
Active member
Yes the intake has been cleaned. That's what I that also the ecu 
Curious Chris
Top Post Dawg
1. Get VCDS
2. Run Drivribiwire diagnostic test: logging Specified MAF, Actual MAF, Specified MAP, Actual MAP and Throttle position, 2000 rpm to to 4200 RPM repeat 3 times. Send log to chrisidzerda@gmail.com
On my 1990.5 Golf I had a no CEL MAF failure. By doing the log I could see that the MAF hit specified then just faded to idle mode.
2. Run Drivribiwire diagnostic test: logging Specified MAF, Actual MAF, Specified MAP, Actual MAP and Throttle position, 2000 rpm to to 4200 RPM repeat 3 times. Send log to chrisidzerda@gmail.com
On my 1990.5 Golf I had a no CEL MAF failure. By doing the log I could see that the MAF hit specified then just faded to idle mode.
oilhammer
Certified Volkswagen Nut & Vendor
The MAF test is irrelevant if the EGR has been messed with. This is why I loathe when people mess with things when they do not actually understand what they are messing with and how it relates to other things. That is why I asked how the EGR was changed, and if software was involved. I'm really not sure the OP even understand's the context of my question.
I have an ALH that has a MAF delete tune... largely to delete the EGR. It runs fantastic. But its MAF log would be completely useless to diagnose anything, as it is a fixed 450, never changes... idle to redline... 0 to 100% go pedal... makes no difference.
I have an ALH that has a MAF delete tune... largely to delete the EGR. It runs fantastic. But its MAF log would be completely useless to diagnose anything, as it is a fixed 450, never changes... idle to redline... 0 to 100% go pedal... makes no difference.
I had an ALH with no CEL but the intake clogged with carbon
fatmobile
Veteran Member
Sometimes people clean the intake but not the intake ports.
Warthog
Veteran Member
What do you know about the injectors? Might be bad, too.
Clogged intake manifold is first thing that comes to mind, but the intake ports on the head are probably a mess too.
Are you getting turbo boost? Be careful here...if the turbo is not running and you DO find our why and FIX it, you might have a runaway. Drain the intercooler and see how much oil comes out. You can drill a small hole in the bottom at the lowest point for a drain, and plug it later with a big sheet-metal screw with a simple gasket.
Experience on the runaway business. It's not what you want to have happen!
Clogged intake manifold is first thing that comes to mind, but the intake ports on the head are probably a mess too.
Are you getting turbo boost? Be careful here...if the turbo is not running and you DO find our why and FIX it, you might have a runaway. Drain the intercooler and see how much oil comes out. You can drill a small hole in the bottom at the lowest point for a drain, and plug it later with a big sheet-metal screw with a simple gasket.
Experience on the runaway business. It's not what you want to have happen!
Jason25klein
Active member
So the best way is to take off the intake to clean it? Then I can look at the head also? I don't know anything about the injectors. I just ordered a boost gauge to check the boost out
Jason25klein
Active member
So the maf sensor ne er was replaced and I kept getting a code so 8 replaced it. Definitely helped, BUT still not right sluggish and still not much power but will Rev past 2k
BobnOH
not-a-mechanic
The MAF is often blamed for other issues. I'll bet most of us have a spare in the parts drawer. It's just so easy to replace. Seems you've ruled it out, look elsewhere, go back to begin on diagnosis. Good ideas in the low power thread in my signature. MyTurboDiesel also has some links for low power/Limp mode diagnosis. The intake should be fine, most of the clogging would have occurred before we started using ULSD.
Bit of history might help us. Did the car ever run right, how long ago and any maintenance/repair done near the time it started acting up.
These cars are pretty simple, if a bit different.
Bit of history might help us. Did the car ever run right, how long ago and any maintenance/repair done near the time it started acting up.
These cars are pretty simple, if a bit different.
Jason25klein
Active member
I bought it running like this. So I just started trouble shooting. Intake looks good. I mean I can't see the intake valves but that have to be in the worse case