home register FAQ memberlist calendar

Go Back   Turbobricks Forums > Mechanical > maintenance & nonperformance

Reply
 
Thread Tools Display Modes
Old 04-21-2019, 08:57 AM   #1
jamesinc
WD-40 Enthusiast
 
jamesinc's Avatar
 
Join Date: Dec 2010
Location: Sydney, Australia
Default World's most stubborn running issue

I've been chasing this on and off for like two years.

I have a 1991 240 wagon, M47, LH-2.4. It is hard to start when cold (takes a couple goes of long cranking), then it idles badly, like it has a miss. It smoothes out a bit at higher rpm. It jerks a lot when the throttle is just open a tiny bit. On the highway at 110km/h the temp starts to creep up and it starts losing power. I saved it from the scrap heap, here is a list of all the things I know:

Compression test good (~180psi on all four)
Cap is new
Rotor is new
Leads are new
Plugs are new
Swapped coil no change
Swapped AMM no change
Swapped power stage no change
In-tank pump is new (and can run as single pump)
Main pump swapped with known good one
Fuel filter is new
Fuel tank swapped (old one rusted)
ECU swapped
EZK swapped
Entire LH-2.4 wiring harness swapped
ICV tested OK
No vac leaks
ECT swapped no change
Knock sensor swapped no change
CPS tested OK (new anyway)
O2 sensor new and tested OK
FPR swapped no change (tested pressure at rail and it was fine)
Fuel rail and injectors swapped no change (was concerned old ones might have been clogged with varnish)
Head rebuilt no change
Bottom end looked good from what I saw with the head off
Thermostat new

Only other odd thing is that the temp gauge reads lower than other 240s I've had (8 o'clock position compared to the usual 9)

I'm starting to suspect the car is under some kind of spell.

Hit me with your best ideas
__________________
1985 240GL, 1989 740 Turbo wagon, 1992 240, 1977 244DL, 1980 244GL, 1996 850R wagon, 1985 360GLT

Founder of the Australian Volvo fourms, http://ozvolvo.org
jamesinc is offline   Reply With Quote
Old 04-21-2019, 10:38 AM   #2
apachechef
Burnt Sierra Madre
 
Join Date: Jan 2009
Location: Fort Joe Smith, Klendathu
Default

Vac leak accordion hose
__________________
Quote:
Originally Posted by lummert View Post
Dammit, Lummert.
Quote:
Originally Posted by Jesse8931 View Post
Well keep us updated on how your dumbass plan goes.
apachechef is offline   Reply With Quote
Old 04-21-2019, 10:46 AM   #3
NotSoFresh
Sick ****** T-Brick Prick
 
NotSoFresh's Avatar
 
Join Date: Aug 2008
Location: gangcouver
Default

Quote:
Originally Posted by jamesinc View Post

Only other odd thing is that the temp gauge reads lower than other 240s I've had (8 o'clock position compared to the usual 9)

I'm starting to suspect the car is under some kind of spell.

Hit me with your best ideas
My '89 also reads at 8oclock normally.
You seem to have checked most everything. My wonder is if there is rust and junk still in the fuel lines after the tank swap and it has fouled the new filter.
Only other thing I dont see is the IAC, It can test fine electrically and still be gummed up.
Here is a thread on this, and the guy had similar issues to you.
At least his car....I no nothing of personal issues....
https://www.matthewsvolvosite.com/fo...ic.php?t=88122
NotSoFresh is offline   Reply With Quote
Old 04-21-2019, 01:31 PM   #4
dl242gt
300+hp on the shelf club
 
dl242gt's Avatar
 
Join Date: Jun 2002
Location: S NJ, a suburb of Phila.
Default

There is a known starting issue with the LH2.4 and there is an updated eprom for the ecu to help with the problem. Volvo had this available and maybe it will help with your issues.

Also you didn't mention which ecu you have swapped. I would try a 951 instead of the 561 and see if that helps.
dl242gt is offline   Reply With Quote
Old 04-21-2019, 06:18 PM   #5
jamesinc
WD-40 Enthusiast
 
jamesinc's Avatar
 
Join Date: Dec 2010
Location: Sydney, Australia
Default

I replaced the accordion hose - the old one did indeed leak, sorry I forgot to mention that one.

It's running a 951 ECU currently. I swapped in a couple different ones and they all performed more or less the same.

I cleaned the ICV pretty thoroughly and it looked okay, no movement restriction etc. I have a spare I can swap in so I'll try that just to be safe.

I increasingly think some kind of residual junk in the fuel system might be the culprit, I just can't think of anything else. The fuel at the rail is clean, and pressure is steady (3 bar or 3.5 bar I forget what the correct pressure of off the top of my head but it reads correct). I wonder if you can have fuel delivery problems even with pressure looking okay.
jamesinc is offline   Reply With Quote
Old 04-21-2019, 07:03 PM   #6
lummert
Board Member
 
lummert's Avatar
 
Join Date: Jan 2008
Location: Portland IN
Default

Injector o-rings?
__________________
Trying to understand stupid people is like trying to pick up a turd by the clean end.
lummert is offline   Reply With Quote
Old 04-21-2019, 07:42 PM   #7
jamesinc
WD-40 Enthusiast
 
jamesinc's Avatar
 
Join Date: Dec 2010
Location: Sydney, Australia
Default

Quote:
Originally Posted by lummert View Post
Injector o-rings?
I did those too. The old ones were dry but didn't appear to leak
jamesinc is offline   Reply With Quote
Old 04-21-2019, 10:52 PM   #8
11BC2
Board Member
 
Join Date: Dec 2014
Location: Cool, CA.
Default

Pressurized smoke is the most reliable method to check for leaks.
11BC2 is offline   Reply With Quote
Old 04-21-2019, 10:56 PM   #9
jamesinc
WD-40 Enthusiast
 
jamesinc's Avatar
 
Join Date: Dec 2010
Location: Sydney, Australia
Default

Quote:
Originally Posted by 11BC2 View Post
Pressurized smoke is the most reliable method to check for leaks.
I have a smoke machine and an air compressor, maybe I can Macguyver something together
jamesinc is offline   Reply With Quote
Old 04-22-2019, 01:43 AM   #10
jamesinc
WD-40 Enthusiast
 
jamesinc's Avatar
 
Join Date: Dec 2010
Location: Sydney, Australia
Default

Had a look at the plugs just now and it's definitely running lean. Given LH-2.4 is closed loop I imagine it has to be fuel delivery
jamesinc is offline   Reply With Quote
Old 04-22-2019, 02:23 AM   #11
Mr. V
Board Member
 
Mr. V's Avatar
 
Join Date: Jul 2004
Location: Portland, Oregon metro
Default

I had a similar issue with my '86 744Turbo: turns out it was a bad coolant temperature swithch, sending incorrect info to the ECU.

Replaced it and the problem ended.
Mr. V is offline   Reply With Quote
Old 04-22-2019, 10:22 PM   #12
bobxyz
Board Member
 
bobxyz's Avatar
 
Join Date: Aug 2014
Location: Boulder, Colorado
Default

Quote:
Originally Posted by jamesinc View Post
It is hard to start when cold (takes a couple goes of long cranking), then it idles badly, like it has a miss. It smoothes out a bit at higher rpm. It jerks a lot when the throttle is just open a tiny bit.
Does the poor idle go away completely once it's warmed up? If not, try a power balance test -- at idle, or a bit above, pull each injector connector, one at a time, and see how it behaves. If one cylinder doesn't seem to do anything, then there may be injector or spark problems.

You could also unplug the ECU and test the coolant temperature resistance at the ECU connector pins (just touch the pins lightly, don't shove the meter probes into the pins or you'll damage them).
bobxyz is offline   Reply With Quote
Old 04-26-2019, 07:04 PM   #13
shoestring
Board Member
 
shoestring's Avatar
 
Join Date: Jun 2009
Location: Swampscott, 01907
Default

Is there anything else going on with this car besides this? Do you have some kind of huge cam in it or something or is it just strictly stock? Given this list of stuff you've done, it's tough to say. Sounds kinda like bad cam timing to me, if everything else listed is known good, especially with the temp creep and loss of power.

Wait...is the cat plugged?
shoestring is offline   Reply With Quote
Old 04-27-2019, 04:12 PM   #14
2manyturbos
Moderator
 
Join Date: Mar 2003
Location: Monroe, OR USA
Default

I read your list of parts you changed and see no mention of the crank position sensor. A failing crank sensor will behave exactly as you describe. I've saved several Volvos from being scrapped due to a failing cranks sensor that shops/Volvo "experts" misdiagnosed. It's not simply a case of the CPS works or it doesn't.
2manyturbos is offline   Reply With Quote
Old 04-28-2019, 05:00 AM   #15
jamesinc
WD-40 Enthusiast
 
jamesinc's Avatar
 
Join Date: Dec 2010
Location: Sydney, Australia
Default

Okay, finally resolved it. (also the crank sensor was replaced not too long ago). Sorry for the utterly lame result, the flywheel was off by 45 degrees. It gets a bit more complicated, because the crank pulley TDC mark was placed incorrectly, based on the original flex plate position, which I had assumed was correct (I pulled this car from a yard and had no reason to think anything had been messed with).

So the timing strobe originally showed the expected 10° BTDC #1 plug ignition event, but actually it was more like 55° BTDC. Amazing that it ran at all TBH.

It's not quite as dumb as it sounds - this car did have nearly everything wrong with it, there were fuelling issues, cooling issues, sensor issues, etc, and I think the mix of so many problems meant I overlooked the possibility of there being a crank timing issue for ages. It's only recently when everything seems to be working that I really hunted for it. In the end I found TDC with a dial gauge setup through the #1 spark hole and suddenly it alllllll made sense.

Thanks everyone for the input, I am just really happy the damn thing works. If you want to see the build it's over on Oz Volvo here: https://ozvolvo.org/discussion/6758/...-the-brapwagon
jamesinc is offline   Reply With Quote
Old 04-28-2019, 02:44 PM   #16
forty2
Newbie
 
Join Date: Nov 2008
Location: Atlanta, GA, US
Default

Dumb question: shouldn't a manual 1991 have LH3.1 like my car does?
forty2 is offline   Reply With Quote
Old 04-28-2019, 06:57 PM   #17
jamesinc
WD-40 Enthusiast
 
jamesinc's Avatar
 
Join Date: Dec 2010
Location: Sydney, Australia
Default

Quote:
Originally Posted by forty2 View Post
Dumb question: shouldn't a manual 1991 have LH3.1 like my car does?
This is an Australian 240, as far as I'm aware we never got LH-3.1 in anything.
jamesinc is offline   Reply With Quote
Old 04-29-2019, 03:46 AM   #18
2manyturbos
Moderator
 
Join Date: Mar 2003
Location: Monroe, OR USA
Default

Quote:
Originally Posted by forty2 View Post
Dumb question: shouldn't a manual 1991 have LH3.1 like my car does?
US market cars came with both LH 2.4 and LH 3.1 when equipped with a manual transmission.
2manyturbos is offline   Reply With Quote
Old 04-29-2019, 05:17 PM   #19
dl242gt
300+hp on the shelf club
 
dl242gt's Avatar
 
Join Date: Jun 2002
Location: S NJ, a suburb of Phila.
Default

Yeah, my 93 classic wagon is LH2.4 happy.
dl242gt is offline   Reply With Quote
Old 04-30-2019, 09:35 PM   #20
durk80
Board Member
 
durk80's Avatar
 
Join Date: Nov 2015
Location: South GA
Default

Quote:
Originally Posted by jamesinc View Post
Thanks everyone for the input, I am just really happy the damn thing works. If you want to see the build it's over on Oz Volvo here: https://ozvolvo.org/discussion/6758/...-the-brapwagon
It's great that you documented your progress as one can clearly see you have poured your heart and soul into your new ride!
durk80 is offline   Reply With Quote
Old 05-02-2019, 12:00 PM   #21
shoestring
Board Member
 
shoestring's Avatar
 
Join Date: Jun 2009
Location: Swampscott, 01907
Default

My '91 M47 245 is also LH2.4.

OP-thanks for the resolution post.
shoestring is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -4. The time now is 11:37 PM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.