2004 XC70 - Sluggish when compared to another 04 XC70?

[matthew1]

I don't know about those graphs. 2550 hPa = 37psi, which is wildly off. Not that the graph line is hitting that, just that it makes it subject to the part of my troubleshooting routine where I toss it as not useful.

A $25 boost gauge is invaluable troubleshooting this. It'd be pretty high on my list of to-do/to-buy items here.

With an actual (not calculated, as could be happening with any OBD-II boost graphing) psi, you'd know exactly how far off stock psi the car is. I think on this model stock is 8psi.

[NullenVoyd]

Red highlights follow the bad tubes as best I can. Magenta box on bottom center is some control valve I'm assuming, couple wire connectors on it (circular thing below leftmost red circle in previous pic). Blue line is air box, where the end of that vacuum (or pressure?) line plugs into.

Vac line trace.

I don't know about those graphs. 2550 hPa = 37psi, which is wildly off.

Yea, that is max for the graph but it never reached that. Didn't auto-range output so they hopefully looked similar enough for semi-useful comparison, but that VIDA datalogger leaves much to be desired.

[vtl]

This is a part of EVAP system.

Upper hose goes to the MAF-turbo pipe (always has at least a bit of vacuum), middle goes to inlet manifold (a lot of vacuum when not under boost), bottom goes to the EVAP purge valve.

Replace them with a silicon hoses. While replacing them, do a mouth-check of two vacuum valves: should not pass any vacuum in one direction (against the arrow).

[NullenVoyd]

Thanks vtl.

Replaced lines and checked valves and all seemed well on that end. Also found most of the hoses around the brake booster vacuum ejector were loose, so popped off the old clamps and put new ones on and now that's all tightened up.

Didn't resolve the performance, but at least that end of things is in better shape. Going to track down a decent vac tool and see if I can find anything out on the turbo related lines, but that might be a few days.

[vtl]

Were the graphs taken in neutral/parking?

[NullenVoyd]

Were the graphs taken in neutral/parking?

The spikes you see were under load taking a quick zoom around the block. Fairly level ground. Something like a rolling start to about 40ish mph about 3 times with the pedal pretty solidly down, for each car. The actual numbers in the lower right by the sensor description and colour key are at idle for each car after stopping from one trip around the block.

I'm actually having a creeping suspicion that the old XC70 was tuned, plus it has the IPD HD TCV, and its turbo was removed and cleaned and had its turbine housing replaced with a better used one (outside piece of wastegate arm was messed up). It has also had its engine replaced, with a used one with like 80k on it (original had about 230k).

Part of me wants to try 'test-driving' a number of other same cars from the same year and see if the real source of the problems here are my expectations, but that's part of why I need some outside input.

Edit: Updated test description and mentioned old XC70 engine replacement.

[vtl]

Can you get to a highway/freeway and push it in 3+ gear? Watch for boost number, just display it alone in large font. Stock engine would have boost ~55 kPa/550hPa over ambient air pressure, so about 1500 hPa in VIDA "ECM Boost Pressure". If your CBV is torn it won't be able to achieve this boost ever. Anything significantly higher than 55 kPa means a ECU tune.

[vtl]

I have about 80 kPa with Hilton stage 1 and 3" downpipe.

[NullenVoyd]

I'll post the graph I got yesterday from the new car along with one I collect from the old car hopefully in the next couple days, but you were dead-on vtl. It hit max 1490hPa when getting on it on the freeway, which suggests heavily the old Voov is likely tuned and new one is working just peachy. I wonder if part of what I'm feeling on the low end (around the block) is the torque limitation removal I've heard ECU tunes tend to remove? Still going to double-check pressures when I get my hands on the right tools, just to verify and get the experience.

This also means I will likely be looking to tune up the new Voov once I get the old one sold and let the holiday craziness pass.

[marcus]

The type of spurk plugs can make it sluggish. Especialy the gap on the electrode makes difference in performance on higher rmps.