Yet Another ETM Thread

Post by **abscate** » 27 Dec 2017, 10:22

Because the ECU controls everything. One day it detects a set of conditions that prompt it to say

" I give up"

And invokes limp mode or lookup table mode. That's predictable when the car is new , but it has a bunch of marginal things , it can run like poop

The classic example for this is " bad MAF"

Engine runs poorly
Disconnect MAF, engine runs well
Brand new MAF, engine runs poorly
Disconnect new MAF, engine runs well

gspences · Post by **gspences** » 27 Dec 2017, 12:33

OK - thanks. I've read some of your other posts on troubleshooting ... suffice it to say I'm learning. And I'm starting to miss my 240 that my son absconded with.

So ... with new plugs/ETM/MAF, new filters, etc, and with the vehicle still in the "I give up" mode, I've had the suggestions of coil pack replacement, fuel pressure & compression testing. I gather things can also go haywire with air/vacuum leaks. Is there a wise approach to progressing down the list of marginal things?

I'm also probably too ignorant to own this car ... I'm a decent mechanic on the 240 but feeling way behind the curve on this 17 yo XC70. Guess I'm mired in the 20th century. So I may have some ignorant questions along the way. I'll try reading a bunch of posts before asking all my questions.

Post by **abscate** » 27 Dec 2017, 12:42

I found this website in 2013 - just as I was ready to dump my V70 for scrap - and have painfully taught myself its foibles.

You haven't offended anyone here - we have all been here at one time or another.

Its slower, but more definite to ask questions and try one thing at at time than a bunch at once.

It is really easy to mess up a throttle body job and leave a hose hanging or split - which will give you an incredibly poor running engine on a turbo.

Post by **RickHaleParker** » 27 Dec 2017, 12:48

That said, when a vehicle very suddenly changes from running like a top to having no throttle response.

Had a Truck that did that. Turned out to be damaged wire to the throttle pedal. It would short to ground, clear, short, clear.

gspences · Post by **gspences** » 27 Dec 2017, 14:59

Yep ... things that make me go "hmmmm." When I had everything off (i.e. intake manifold, fan, etc) I was looking at all the wire with crumbling conduit. I did my best to inspect for any wiring damage but didn't bother to use the multimeter to test anything. I've now added conduit but now you've got me wondering about checking grounds and wires. It's a horribly complicated iteration of "what if THIS is the problem ... what if THAT is the problem."

Speaking of trucks, I had a 70 F100 for awhile. Everything was mechanical ... if something was wrong you could SEE it. I did everything on that truck with a timing light, multimeter, and wrenches. Yep, a carb w/ manual choke takes some tweaking, but I can't help but think those were the good ol' days.

Post by **RickHaleParker** » 27 Dec 2017, 16:38

Everything was mechanical ... if something was wrong you could SEE it.

The reason they stopped giving free estimates for electronics repairs is .. by the time you know what is wrong 90-95% of the job is done.

Decades ago they tried to get the Automotive manufactures to do away with wiring harness and go with a RS232 network of sensors and controls. It would of eliminated a lot of wires and connectors that could go wrong. Finding a defect would be so much simpler. I wish they would go fiber optics for the data network.

gspences · Post by **gspences** » 27 Dec 2017, 18:46

OK - previous input has triggered a thought. The car trouble started (no throttle response, bucking, etc) a day or two after I changed the plugs. Plug changeout was a simple job, but if the coilpacks are a potential trouble spot then might I have "jiggled" something that created a problem? Maybe the timing was coincidental, maybe not. I'll look on here for testing the coilpack ... have no idea how many miles are on the existing.

I'll also go back over all the work I've done ... will remove the turbo pipe and get back down to the throttle body to check hoses/fittings. I reinstalled the ETM with the intake manifold in-place, and it was challenging to get the gasket lined up correctly. If I drop the ETM to double-check the gasket is it necessary to use a new gasket on reinstall? I have a spare if needed. I'll double check the torque around the intake manifold. The other troublesome area I had was the banjo bolt on the underside of the intake manifold ... the easiest for me was installing this after the intake manifold was mounted. I did not use a new banjo bolt and reused the crush washers ... was (is) that important?

Thanks for the comments thus far.

Post by **abscate** » 27 Dec 2017, 19:12

The simple way to check all this us with a smoke test. There are a couple of ways to make smoke and pump it into the manifold and look for leaks. I'll try find threads and link

Reuse that new gasket, it will be fine.

A small leak ( like the banjo washer) won't cause horrible running but it will pop a code, usually a P0171. You are looking for something bigger, I think.

People have had trouble getting the intake manifold seated so check that.

Post by **velorider** » 28 Dec 2017, 01:06

I had the PO102 error a few weeks ago after working on my S60. These cars seem to be very sensitive to air flow. Was the air box hooked up? With just the MAS sensor connected to the intake but no air box that car will idle like crap and stall. The air flow will be turbulent and the sensor will go crazy.

If the air box was connected, check that the air intake tube is properly connected to you turbo and the PTC nipple is properly connected.

Post by **abscate** » 28 Dec 2017, 07:38

Forgot to add. The coils each ground through the M6 bolts as well as the wiring harness. Make sure those bolts are in and the metal they touch is clean.

Yet Another ETM Thread

Re: Yet Another ETM Thread