2006 XC70 Hot starting issues Topic is solved

[Rvolvos]

Having some hot starting issues with our 2006 XC70 191kmiles.
I had starting issues in the past and did get codes ECM5000. Repaired the coil wires. (Cold) starting improved greatly.

When the engine is cold, no starting issues. When hot and turned off and restarted immediately, no problem.
Restarting after 5 or 10 minutes, with a hot engine, engine stumbles and stops, restarting thereafter takes a lot of cranking to get going. Once running very smooth.
Lately mostly driven around town and mileage is down too 16.3mpg.

Relevant Service history:
191k replaced the crank position sensor with a used one. Slightly better cold starting. Code ECM5000 had reappeared.
186k Pcv system serviced, injectors cleaned/ flushed, o-rings replaced. Repaired coil wires. Engine felt more powerful.
181k Evap pump replacement, check engine light came on when reaching half of gas. Throttle body cleaned. Preventative maintenance.
~178k cleaned ecm & Tcm contact s with de-oxide cleaner. Restricted movement of the ecm with a tie wrap wedge in between the slots. Solved the engine going into limp mode.
177k Replaced thermostat with ETC. Sensor. Preventative maintenance
177k spark plugs replaced. Battery replaced. Fuel filter replaced, MAF sensor cleaned. Preventative maintenance
175k Fuel pressure sensor replaced.

Did search the forum for similar symptoms and possible solutions.

For now I have I do not suspect the ETC sensor, since it has been replaced at 177k

I have rented the fuel pressure gauge from Autozone.
First test 44psi after 20 minutes 37psi
Second test engine running first with gauge attached then turned off.
54psi after 20 minutes 42 psi, next morning 4 psi
I did restart the car after 20 minutes the 3 test, pressure went up quickly , started and stumbled a bit too with 50 -55 Psi
Had a Volt meter attached to the positive terminal and ground. Healthy 12.5 Volt with engine off, dips to 9.5V when starting and rises quickly. Positive battery terminal on the battery did not felt hot.
From reading on the forum, possibly causes:
Leaky fuel injector, but how to test?
Bad check valve in fuel line, how to test?
Bad evap purge valve or check valve?
Maf sensor going bad?
Starter drawing too much current?

Any help much appreciated.

[oragex]

Any codes as of now ?

[Rvolvos]

Any codes as of now ?

I need to drive it some more, just replaced the steering angle sensor with a used one and erased the last codes. SAS-000E & ECM-5000.
Thanks much for your response.

[oragex]

Hope you get more answers, but it may not be easy to find fix. From memory
When trying to start with the engine hot, do you hear the fuel pump priming ?
The fuel pressure is a bit low, may look at the PEM for corrosion ($40 off Ebay). Not sure why it's dropping pressure overnight, maybe a leaky FPS ?
Maf contacts https://forums.swedespeed.com/showthrea ... blem/page2
coolant temp sensor wires near the plug (watch the needle moves smooth as it's reaching temperature)
crank position sensor
stripped crankshaft gear splines https://volvoforums.com/forum/volvo-s80 ... ear-89394/
may also remove the ECM modules (see Youtube) and spray some electric grease on the contacts
also verify the wires to the starter (may corrode inside), and the wire at the big connector on top of the radiator fan

[darrylrobert]

Had almost exact same issue with my 2001 xc70 but only on hot days above 25c. I think/hope mine was the purge valve, i also found and repaired a one way valve under the inlet manifold, i have tested the car after updating the purge valve (i had the old style unit) and so far so good but its winter now so wont know for 6months.

[Rvolvos]

Hope you get more answers, but it may not be easy to find fix. From memory
When trying to start with the engine hot, do you hear the fuel pump priming ? Yes!
The fuel pressure is a bit low, may look at the PEM for corrosion ($40 off Ebay). Not sure why it's dropping pressure overnight, maybe a leaky FPS ? I think it is due the the trapped air in the fuel gage. Next morning the gauge went up 4 psi after cycling the key and starting the engine without problems.
Maf contacts https://forums.swedespeed.com/showthrea ... blem/page2
coolant temp sensor wires near the plug (watch the needle moves smooth as it's reaching temperature) etc has been replaced and and needle is raising smoothly and always in the middle.
crank position sensor. Just swapped. Erased the last code ecm-5000. Fault trace reported no errors.
stripped crankshaft gear splines https://volvoforums.com/forum/volvo-s80 ... ear-89394/
may also remove the ECM modules (see Youtube) and spray some electric grease on the contacts. Updated my initial post. I did this after the engine going into limp mode and all sorts of communication errors. ECM had a lot of movement and the limp mode occurred when driving of a curb.
also verify the wires to the starter (may corrode inside), and the wire at the big connector on top of the radiator fan

Thanks much for your response, FYI used your video of removing the airbag and steering wheel to replace the SAS. Very helpful.

[Rvolvos]

Had almost exact same issue with my 2001 xc70 but only on hot days above 25c. I think/hope mine was the purge valve, i also found and repaired a one way valve under the inlet manifold, i have tested the car after updating the purge valve (i had the old style unit) and so far so good but its winter now so wont know for 6months.

Thank much, I may give this a try as well. I did see the check valve in the hose from intake manifold to air intake to turbo.

[Rvolvos]

Cross my fingers;
Cleared all codes, ECM-5000 did not reappear. After looking into this error it happened 255 times since the first time detected. Fault trace verified that the replacement sensor was good.
The stumbling was not solved. I unplugged the MAF sensor and the car started normal ( suggestion I found on this forum). After the second start the check engine came on. I have swapped the MAF sensor from our V70 and it looks like the problem is solved after clearing the codes.
I drove the car with Vida connected and could see the purge valve was working see attached screen shot (0% when idling).

[Rvolvos]

So far no new codes, stumbling During a hot start seems to be gone. But still more difficult to start when hot/ longer cranking then cold.
When driving from work home climbing up the hill I did notice a bit of stumbling and had noticed it before, but ignored it.
I went ahead and swapped the ignition coils from our V70 (154kmiles), didn’t make a difference in starting hot.
Swapped the PEM with one from our donor C30. No difference

I have refurbished fuel injectors on order and that will be my next thing to try.

[darrylrobert]

keep us updated. defiantly issues with these cars in hot climates. i notice your VIDA has alot of parameters for the purge valve, my VIDA has none only 1 parameter for the EVAP canister close valve, which the car doesnt have. what version of VIDA do you have? 2014D?

Does your car have the little fan for the ECM, mine doesnt, the ECM gets really hot on warm days. I have one on order, i hope its not lost at sea, i plan to wire it to activate whenever the ignition is on. Ive heard of people putting computer fans in there.