Hesitation on WOT (V70 2.0 T5 AWD 1997) Topic is solved

Post by **Fiodor** » 23 Nov 2018, 15:29

Nope to both of these questions.

Post by **misha** » 24 Nov 2018, 04:34

Check ALL the vacuum lines 1st before you go further.
What about that fuel you are using?Bio fuel with high percent of ethanol?
It's weaker than standard fuel you should use.
Turbo or non turbo cars need our european premium bmb 95 at least.
Fill the next tank with premium bmb 95,remove negative battery cable for 15 minutes in order to reset old fuel trims and start with that.
With fuel you are using ecu will need to compensate by changing the fuel trims and ignition degree angle to keep the car running at it's best.
It will run with weaker fuel but it will run optimaly,making some compromises between power and consumption.

https://fuelandfriction.com/weekend-war ... -you-know/

Post by **abscate** » 24 Nov 2018, 04:39

We did have this same problem solved by a transition from new Bosch yo new Volvo OEM spark plugs

Post by **Fiodor** » 25 Nov 2018, 04:42

I've changed my fuel and I've replaced the vacuum lines going to the BCS/TCV.
Are there any other vacuum lines that I should check ?
I've bought a bluetooth ELM327 (I'll read the codes with (850-OBDII) and I'll try to change the spark plugs next week.

Thanks for your help !

Post by **misha** » 25 Nov 2018, 05:56

Pcv system vacuum lines
Fuel tank vent lines
Vacuum tree vacuum ports
Sas system(if equipped) vacuum lines
Brake booster vacuum lines
Fpr vacuum line
Fuel tank cap must be OE and tight untill it clicks
Air filter housing vacuum lines
Right side of intake manifold between ps pump and intake manifold...vacuum elbow

A lot of vacuum lines to check!

After changing the fuel to euro premium bmb 95,remove negative battery cable for 15 minutes in order to reset fuel trims.
Perform ecu re-learn procedure after that.

Post by **Fiodor** » 25 Nov 2018, 06:26

Wow, that sure is a lot of vacuum lines.
Could you tell me what the Ecu relearn procedure is please?
Thanks again

Post by **misha** » 25 Nov 2018, 07:38

http://www.volvotips.com/index.php/850- ... rocedures/

Post by **abscate** » 25 Nov 2018, 08:43

Fiodor wrote: ↑25 Nov 2018, 06:26 Wow, that sure is a lot of vacuum lines.
Could you tell me what the Ecu relearn procedure is please?
Thanks again

Fiodor - it is not a good strategy to inspect vacuum lines on a 21 year old car - they are old and begin to crumble at this age. Once you go to the trouble of removing them, just replace with new ones. You can see a picture of what why vacuum line looked like here - even though inspecting the parts you can see were looking good!

Post by **Fiodor** » 26 Nov 2018, 14:11

DTCs checked !

COMBI :

124 Engine RPM Signal faulty
221 Vehicle speed signal Missing [bad ABS module solders?]
222 Vehicle speed signal too high

ECC :
414 Driver's (or passenger's) side interior temperature sensor inlet fan seized (or open/short circuit or faulty signal)

The 3 COMBI DTCs remain after erasal.
What could be causing these ?

Post by **misha** » 26 Nov 2018, 15:07

What is COMBI?
Instrument cluster?
Is your speedometer working?
Manual or automatic transmission?
What scanner/code reader did you used?

Hesitation on WOT (V70 2.0 T5 AWD 1997) Topic is solved

Re: Hesitation on WOT (V70 2.0 T5 AWD 1997)