HArd warm start 1989 240 DL, lh 2.4, AW70, 316k km

sergitin32 · Post by **sergitin32** » 04 Oct 2018, 22:34

Hello.

Recently I have been diagnosing my other 240 (wagon) and did a switch of ECU to determine if the others ECU was faulty... since then and it might be a coincidence, but since that time this car (sedan) is having a hard time starting when warm. The harder you drive the car the harder it is for it to start later on, as soon as it cools down a little it starts, and once it does it does not bog or sputter, idle is even and the car runs fine. Computer codes deliver 1-1-1 in both tests.

I went through the first step and switched the air filter, then while there notices a ton of oil in my intake, I guess oil separator box needs attention (ordered new flame trap kit from FCP, two of them) took the box out and found the return piece of this box to be broken inside the crankcase, dang it! pulled out and in the meanwhile used some MAF sensor cleaner from IDP to clean the mass flow sensor and the oily hoses around it. Cleaned the oil separator and epoxy-glued the broken end; Will wait for the fire trap to get here to put it together.

Next in line will clean the throttle body and change the RPM or crankshaft position sensor, I noticed the vire peeling in the outside in both vehicles (will change them in both cars).

Any other reason why the car won't start when warm but start no prob when cold? Power stage?
Is there a warm start valve in these cars? I remember there was one in my older (carbed) 1983 Volvo giving me no start issues once.

I have IDP wires and sparks changed in a timely manner. Brass fuses throughout. Main ignition 25 amp fuse in the engine bay for is clean and well.

Other than this, the car runs fine.

Thanx a lot

Sergitin

lummert · Post by **lummert** » 05 Oct 2018, 12:26

Coolant temperature sensor?

sergitin32 · Post by **sergitin32** » 05 Oct 2018, 15:09

If the coolant temp sensor was faulty wouldn't it give me a code in the FI system?
From experience in my other car where I had to change it... Also the other car with a bad coolant temp sensor used to flood when warm so it would stall, this one does not stall, it is only hard to start once warm... Thing is, as I read more and more, sometimes sensors are substandard and their signals are just crappy and noisy, also they might not get codes... So I will keep this in the back of my head for the future and if things don't get better on the way I will just put a new CTS in there just for the sake of it, even when this is a pain in the rear to reach and change thou!

Thanks for the advice lummert.

Sergitin.

93Regina · Post by **93Regina** » 05 Oct 2018, 19:30

sergitin32 wrote: ↑04 Oct 2018, 22:34Any other reason why the car won't start when warm but start no prob when cold?

Explain what is done to do a cold start?

Flip the key, or flip to on, wait, then to start?

sergitin32 · Post by **sergitin32** » 06 Oct 2018, 00:57

Hi 93Regina:
I normally get to the car when a few days without driving, turn the key to the first step and listen for the pump to preload...
Give it a glitch of a sec and then crank the engine... it would take maybe 4 revolutions to come alive.
Never fails in cold start... this is in an underground parking, no heating but still not out in the cold of winter. Max, I would say it goes close to 0 in the early winter morning. After that, I turn on the lights since it doesn't have daylights... I've got a module for that pendant installation. Click seatbelt and, wait no more, its time to drive... easy on the throttle now since gas is $1.50 per liter of regular which is what I always use (87) and it seems OK for the car. When the car gets to operative temperature (90 degrees thermostat I believe) I get a little more playful with my driving... Still feeling guilty for the damn fuel prices!

Thanks for reading.

Sergitin.

sergitin32 · Post by **sergitin32** » 07 Oct 2018, 14:12

Hi guys,
when I removed the oil separator box and flame trap I did notice the fatty short and wave-shaped hose that connects this two things had a couple of big cracks, which makes me think there could be a vacuum leak here through the vacuum hose going to the manifold just before the flame trap... which was very much full of oil. Maybe that's why the warm start was too lean to do so properly? When cold compensating with more fuel would make the mix rich again and so. weird is that the idle would hold nice and steady but well... I am changing the whole flame trap and hose with a kit from FCP Groton in both cars soon and reporting back if this did it for me.

Thanks.
Sergitin

sergitin32 · Post by **sergitin32** » 07 Oct 2018, 23:20

Found this piece of diagnosis advice from https://www.volvoclub.org.uk/faq/Engine ... ction.html

"Tips from Bob Dietz] When the car dies run a test light from the negative side of the coil to ground. If the light flashes brightly when you bump the starter then all the ignition components are ok, and the fuel pump should run for a few seconds. If the light barely flashes and the fuel pump doesn't run, then suspect the ignition amplifier (between the air filter housing and the inner fender wall.) If the light flashes and the fuel pump doesn't run, suspect the fuel injection relay (the white relay behind the ashtray--remove the lighter, lighter cover plate, two screws and the ashtray to access). Pull the cover off and reinstall, turn the key to run position and operate the contacts by finger. If the fuel pump runs, then the relay is suspect--resolder or replace--your choice. If by turning the key to start and holding the fuel pump point set closed the car runs, release finger pressure on the fuel pump contacts. If the contacts stay closed for a few seconds after you release the contacts then the relay is bad and the fuel injection control unit is ok. If the motor shuts off as soon as the fuel runs out after you take finger pressure off the relay contacts then replace the relay and the fuel control unit--the protection diode on the relay has failed and wounded the computer."

Trying that next time I check the car... power stage under suspicion here.

lummert · Post by **lummert** » 08 Oct 2018, 10:17

Does this car have a tachometer?

sergitin32 · Post by **sergitin32** » 08 Oct 2018, 14:35

Yes it does, a small one recently installed by me... I assume if it moves means the same as the test light???

sergitin32 · Post by **sergitin32** » 09 Oct 2018, 01:51

OK, I tried to delete my last long post from this thread since it was actually meant for my other car in another thread in this forum, which is a no start, somehow did not manage to do so. Sorry about that.

For this car, I got the oil separator box from the other car(1992 wagon)this was very clean and the flame trap was immaculate as well were the hoses all around it, so I borrowed them for this 1989 sedan. The box from the '89 car was broken and after trying different glues it didn't work out, so I will order one soon from IPD or FCP. After fidelling a lot to get things in there (so tight) I managed to get it done. After that, I went to the gas station and put some gas into the car since it was very low. The car started alright a few times, including on the way back from the gas station when it was fully warm. For now, I will call it a fix, and report back if something goes awry in the future. I believe the hose from the oil separator box to the flame trap been cracked might have put some undesired unmetered air into the intake through the vacuum pipe causing a lean condition when warm. In the next few days, I will nevertheless change the crank position sensor and clean the throttle body as completion of the tune-up.
Thanks for reading and putting your 2cents in.

Sergitn.