General Power loss on 96 2.5Turbo Diesel-pls help

[1996-850-TDI]

Hi All

Just joined and this is my first thread. I'm experiencing sudden power loss on my 2.5TDI. It's intermittent and does not happen on ever journey. It usually happens when in second gear and accelerating. I brought it to a garage and no error codes showed up and they could not figure it out. I don't want some garage to just start replacing fuel pumps etc if they don't even know what the problem is. I've searched the net and found that lots of 850s had the same problem and I was sure it was the fuel pump relay (Red 103). Is there a fuel pump relay on a diesel? I took the cover off the fuse box where this is supposed to be located but there isn't fuel pump relay as described.I only have the green (104) and three black fuses with J on top(Most info relates to 850 petrols.) Would really appreciate your help. Thanks, Paul

[outnumbered]

Originally Posted by 1996-850-TDI

Hi All

Just joined and this is my first thread. I'm experiencing sudden power loss on my 2.5TDI. It's intermittent and does not happen on ever journey. It usually happens when in second gear and accelerating. I brought it to a garage and no error codes showed up and they could not figure it out. I don't want some garage to just start replacing fuel pumps etc if they don't even know what the problem is. I've searched the net and found that lots of 850s had the same problem and I was sure it was the fuel pump relay (Red 103). Is there a fuel pump relay on a diesel? I took the cover off the fuse box where this is supposed to be located but there isn't fuel pump relay as described.I only have the green (104) and three black fuses with J on top(Most info relates to 850 petrols.) Would really appreciate your help. Thanks, Paul

hi paul
welcome to the forum
what scanner where the garage using, i would check the following, all electrical connectors ie maf, boost cables, there is also a 8 pin plug under the fuel pump, if you follow the dipstick down towards the engine block near the pump is a 8 pin connector take it of and give it a good spray with brake cleaner, also check all inter cooler pipes and vac pipes there is quite a few. does it only do it in second or all gears .
hope that helps
mike
850 tdi

[1996-850-TDI]

Thanks Mike. To be honest I've no idea what scanner they were using but will find out. Thanks for the tips. Do you know where I could get a service manual for the TDI? I've searched for manuals ie Haynes but they don't seem to produce one for the diesel. It's not limited to second gear but I haven't noticed it in 4th or 5th. It usually happens when accelerating from second especially if you have slowed to a yield sign or in traffic and go to speed up again. The power loss only happens for a few seconds (2-5) and then takes off as normal but makes city driving a very uncomfortable. When it's not happening the car is perfect given its age and miles (175,000 miles/volvo serviced since new). I'll be back with updates if I figure it out. Thanks again.

[dan_V70tdi]

Hi Paul

Because we've got the Audi lump, you'll need to get one of these. See here.

Don't pay full price at Halfrauds or the like though, there's normally one or two available on a well known auction site for only a few pounds.

Sorry, can't help with the power loss problem. Mike's plan sounds like a good one!

Dan

[harveyu]

Hi Paul. I'm a new member and was looking for help on a totally different problem but spotted your post. I had an almost identical problem on my 850 2.5tdi (now solved) Details as follows.

I had a loss of power, slowley getting worse over about 6 months until it was becomming almost undriveable. (But economy was great) it started and ran very smooth, just no power and I could be out accelerated by average white van man. Eventually got around to lifting the bonnet.

The problem was the small sensor pipe which comes from the big intercooler pip on the top right (big black thing with a little pip coming off it). The small pipe spiggot had come loose from the main intercooler pipe. From what I could tell (tracing the small pipe) the turbo preasure from the intercooler pipe fed through this small pipe controlled the turbo wastegate and fueling. Hence where it was breaking off the main pipe it was dropping preasure. Hence was not telling the system to put in more fuel for the turbo preasue, but worse potentially over preasuring the turbo (no wonder I got good economy, no fuel in but lots of turbo boost). I just glued it back in place and problemo solved.

So check that big intercooler pipe is correctly connected to the sensor pipe, and that sensor pip has no splits in it to let out the boost preasure the sensors rely on.

I hope this helps

regards

Harvey

[1996-850-TDI]

Cheers Harvey. Unfrotunately it's gotten worse. Don't know if it's the same problem that's gotten worse or something else but now the car starts and but when you try to take off it cuts out completely. Didn't get a chance to get it to a garage before now but no choice now. Getting it towed tomorrow and hopefully I can finally get a fixed. I'll make sure to check those pipes, would be nice if it was a simple fix. I'll be back with updates.

[1996-850-TDI]

Hi All

I'm back again with some pictures. The garage didnt know what was wrong so untill i find a mechanic that is familar with diesel 850 volvos I'm going to try and fix it myself. I'd prefer to buy parts than waste money on labour and end up with nothing. I've taken the advice given and I'm starting with checking the vac pipes and MAF sensor. I checked the pipes and found that two pipes were disconnected. I've attached some pictures in a word doc so please take a look and let me know what you think. I've put two yellow arrow on both disconnected pipes. I reconnected them and I can drive but still looses power sometimes between 1600rpm and 2000rpm. I would now like to check the MAF as it seems to casue many of these problems. This is where I need your help. I want to know the location of the MAF sensor. I've attached pictures of what I think the maf sensor is. If I am correct can you tell me exactly what I need to do to clean it or replace it. Thanks again for your help.
Paul

[outnumbered]

Originally Posted by 1996-850-TDI

Hi All

I'm back again with some pictures. The garage didnt know what was wrong so untill i find a mechanic that is familar with diesel 850 volvos I'm going to try and fix it myself. I'd prefer to buy parts than waste money on labour and end up with nothing. I've taken the advice given and I'm starting with checking the vac pipes and MAF sensor. I checked the pipes and found that two pipes were disconnected. I've attached some pictures in a word doc so please take a look and let me know what you think. I've put two yellow arrow on both disconnected pipes. I reconnected them and I can drive but still looses power sometimes between 1600rpm and 2000rpm. I would now like to check the MAF as it seems to casue many of these problems. This is where I need your help. I want to know the location of the MAF sensor. I've attached pictures of what I think the maf sensor is. If I am correct can you tell me exactly what I need to do to clean it or replace it. Thanks again for your help.
Paul

hi paul
can not open your file sorry.
mike

[1996-850-TDI]

I attached the pictures but couldnt but the arrows on. One pipe that was disconnected is the black one in the centre of the picture with the blue tape on it. The second that was disconnected is towards the bottom left of the picture and it's white. Please also have a look at the second picture and let me know if I'm looking at the MAF.
Thanks
Paul

[ivor940]

Hi Paul, I dont know where in Dublin you are based, but "Johnmorl" has a v70 TDI and he uses a Bosch diesel workshop in East Wall, Dublin.
Also ask for workshops with Audi A6 / A4 2.5 diesel capability as it is the same engine.

ivor940