Hard to start?

Tiny
SKRY28
  • MEMBER
  • 1997 VOLVO 940
  • 129,299 MILES
I owned volvo 940 turbo which was manufactured on 1997. Recently, I change fuel pump, fuel filter, fuel regulator, air mass, plug, cable plug, oxygen sensor, and crank sensor. So the problem is that my volvo hard to start sometimes I have to put fuel at the fuel regulator to start up. What is the problem? Second problem, once I can start the start the car cannot rev. I will upload the video soon and give the link to you so you will understand what I mean.
Monday, May 21st, 2012 AT 2:01 PM

14 Replies

Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
Is the MIL indicating and prior to replacement of the parts concerned, was there any trouble codes?

This guide can help us

https://www.2carpros.com/articles/engine-cranks-excessively-before-starting

Did you test the fuel pressure before and after replacement of fuel pump?
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Monday, May 21st, 2012 AT 2:39 PM
Tiny
SKRY28
  • MEMBER
  • 3 POSTS
I have no tried dynos it yet. My mechanic say this that so I just change it. Did u saw the video? Change it due to expired parts one of the reason.
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Monday, May 21st, 2012 AT 2:43 PM
Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
No I did not because I could not see anything except advertisements on the links you provided.

What do you mean by expired parts? Never heard of the term for automobile parts.
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Monday, May 21st, 2012 AT 3:08 PM
Tiny
SKRY28
  • MEMBER
  • 3 POSTS
Are you sure u cannot open the video? sorry not expired parts. sorry that is the term we use here in Brunei - cannot used anymore. once the car start i cannot rev it. and hard to start sometimes i hve to put fuel into the fuel regulator hose so it can start

1. http://www.mediafire.com/download.php?9pn70nhsn980ljk
2. http://www.mediafire.com/download.php?319imz1o95388oc
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Monday, May 21st, 2012 AT 3:13 PM
Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
The video is of no help because it is taking me more than 2 hours to donw load and hangs.

Seems the injectors are not firing or you have a fuel pressure problem. Test the fuel pressure first. Perform a leak don pressure test to ensure that there are no leakages within the system.

Have you checked for trouble codes?
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Tuesday, May 22nd, 2012 AT 4:16 PM
Tiny
BERNIEHUNT
  • MEMBER
  • 3 POSTS
  • 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
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Wednesday, November 25th, 2020 AT 7:58 AM (Merged)
Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
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?
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Wednesday, November 25th, 2020 AT 7:58 AM (Merged)
Tiny
BERNIEHUNT
  • MEMBER
  • 3 POSTS
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.
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Wednesday, November 25th, 2020 AT 7:58 AM (Merged)
Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
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.
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Wednesday, November 25th, 2020 AT 7:58 AM (Merged)
Tiny
BERNIEHUNT
  • MEMBER
  • 3 POSTS
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?
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Wednesday, November 25th, 2020 AT 7:58 AM (Merged)
Tiny
KHLOW2008
  • MECHANIC
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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.
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Wednesday, November 25th, 2020 AT 7:58 AM (Merged)
Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
What was the actual cause of the problem?

It has been rectified?
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Wednesday, November 25th, 2020 AT 7:58 AM (Merged)
Tiny
CNDYMYFRND
  • MEMBER
  • 1 POST
  • 1994 VOLVO 940
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 209,000 MILES
We have a 1994 volvo 940 It revs about 90 percent of the time. The mechanic was sure it was the fuel control valve. It still revs, it also is very hard to start first thing in the morning and all day long it will crank and crank and smell flooded. Eventually it will crank to a start. Someone has suggested that it is possibly an o2 sensor. What do you think?
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Wednesday, November 25th, 2020 AT 7:58 AM (Merged)
Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
Hi cndymyfrnd,

O2 sensor should not be causing the difficult starting.
The crank sensor would be more likely to cause it. Check for sparking at plugs and fuel pressure when it cannot start.

Get a scan done to find out if there is any error code.
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Wednesday, November 25th, 2020 AT 7:58 AM (Merged)

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