1994 Volvo 940 Hard to cold start after sitting overnight

Tiny
BERNIEHUNT
  • MEMBER
  • 1994 VOLVO 940
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 191,000 MILES
After sitting all night, cranks long and studders, as if miss-firing, burns small puff of blue oil smoke, in 10 to 15 seconds cleans out and runs normal. Will start OK unless it sits for many hours.

runs fantastically, full of power with turbo, ho oil burn, oil changed every 3k miles, 191k miles well maintained.

Volvo checked fuel delivery, pressure, and changed the fuel pump and injector relays. Changed the rotor, cap, wires and platinum plugs.

Volvo thinks it is oil fouling the plugs due to valve stem seal and stem wear. I do not.

It appears to be injector related or idle-to-start-up injector related.

what do you think, please
Do you
have the same problem?
Yes
No
Sunday, May 10th, 2009 AT 7:52 AM

7 Replies

Tiny
KHLOW2008
  • EXPERT
Hi berniehunt,

Thank you for the donation.

Is your vehiclec turbo charged?
Was any trouble codes retrieved by Vovlo personnels? If yes, what were they?
Was this
answer
helpful?
Yes
No
Monday, May 11th, 2009 AT 10:51 AM
Tiny
BERNIEHUNT
  • MEMBER
Volvo could not re-create or get any codes
they checked the fuel pressure and eventually changed the injector relay and the fule pump relay

they now think it is oil valve stem seals and oil is fouling the plug(s). There is not much of a puff of blue smoke, and at times, none. It seems not to be getting fuel at start up.

Do the injectors behave differently at time of cold start, spray differently.
Was this
answer
helpful?
Yes
No
Tuesday, May 12th, 2009 AT 5:37 PM
Tiny
KHLOW2008
  • EXPERT
During cold start the Engine Coolant Temperature sensor would inform the ECM to provide signals for the injectors to spray a richer fuel.

That is one of the items that should be checked. It could be providing the wrong signal to the ECM.

Leaks from valve stem seals would foul the spark plugs but not immediately. It would start with carbon build up and then misfires and fouling. New plugs should eliminate the hard starting, at least for a short period of time till the plugs fouls up.
Was this
answer
helpful?
Yes
No
Wednesday, May 13th, 2009 AT 8:05 AM
Tiny
BERNIEHUNT
  • MEMBER
Thank you. The heater stopped working recently and the coolant sensor was bad and replaced. Might be related? We can look into this.

So you do not think the injectors need to be cleaned?
Was this
answer
helpful?
Yes
No
Wednesday, May 13th, 2009 AT 5:05 PM
Tiny
KHLOW2008
  • EXPERT
If the problem was not there before the heater stoped working, then the ECT should be loked into. Check the wire connectors for contamination and secure connections.

I don't think it is caused by the injectors. If they are faulty, you would have performance related issues even after the engine has warmed up.

It should be more of a control problem or might be due to insufficient fuel pressure. Testing the fuel pressure would be recommended if others fail to show anything.
Was this
answer
helpful?
Yes
No
Thursday, May 14th, 2009 AT 10:28 AM
Tiny
BERNIEHUNT
  • MEMBER
Thank you
completed
Was this
answer
helpful?
Yes
No
-2
Thursday, May 14th, 2009 AT 10:30 AM
Tiny
KHLOW2008
  • EXPERT
What was the actual cause of the problem?

It has been rectified?
Was this
answer
helpful?
Yes
No
Thursday, May 14th, 2009 AT 8:48 PM

Please login or register to post a reply.

Recommended Guides