Help, I missed Defi 'cause the Volvo's puking!

Hey all you volvo pervs, I missed spectating Defi today as my beloved 85 240 is not happy.

Maybe someone here can provide some direction to getting this poor thing running.

Here's the story...

I went away for work and left the car for my partner. It died one day when she took it to work, but 'luckily' near the volvo shop I normally get parts from.

They spent 3 days trying to get it sorted and gave up. Now I'm back and left to clean up the mess (not that they did bad work, just I think they gave up feeling it wasn't worth putting any more time into, and to be honest I'm glad as the bill was high enough!)

When it quit the first time, it just quit. Didn't slowly loose power or miss, just quit. They got it running (they're not sure what they did!), but it idles fast (over 1500) cold, when warm, doesn't idle, stalls or hunts. White plugs, and pings when trying to accel on the highway. Will go down the highway but misses bad (enough to have driveline lash) every 30 secs or so. Once warm if it gets below 2000 rpm hard to get it back up, will miss puke spit etc. Of course this is the pre dignostic system so I have no little flashing light to tell me where to go.

Things that they did to the car.

New in tank pump.

Changed intake manifold gasket

New plugs,

New bits of wire harness

Swapped ECU (no change old one back in)

Swapped Mass Air (no change old one back in)

Cleaned CIS valve.

I'm about to dive into looking at the injector harness closely, but also harness in general.

Any thoughts, suggestions or a free set of carbs would help!

Oh and for those whom I've chatted on about the Justy... after 4 years of humming and ha-ing we're actually making progress towards getting back on stage. No P1 anymore, so lookout you eastern open classers, 1800 pounds and 90hp is about tear it up! (yeah right, more like - move slowly forward...)

Matt

Try replacing the main fuel pump and filter. Its something basic.

Hi Matt, long time no see.

Check the plastic accordion tube from the air mass meter to the intake. It's been known to crack or wear against the body letting in extra air after the MAF and then you run lean. Your symptoms sound like that.

Check the vacuum hoses as well.

I've seen shorted injectors cause funny running as well. Unplug them and use a digital meter, they each should be about 16 ohms. If you measure backward on one injector plug (up the wiring harness) with the other 3 plugged in you should measure 5.3 ohms which would prove all the injector wiring is in tact. All the injectors are in parallel and fire at the same time.

Since the fuel filter is on the outlet of the pump if it gets plugged the pump will be more noisy than usual.

I assume you have LH Jetronic, and the basic timing is still ok. If the belt slipped a tooth the engine would run poorly, but not just quit outright. I suppose your shop would of checked this but it only take a couple of minutes to take the top cover off the belt. Wind the crank to the timing marks. There is a dimple in the cam pulley and it lines up with a mark in the back half of the timing cover. You may have to go an extra rev on the crank to get the cam in the right position (2:1 ratio)

I'm not sure if your car has the timing / injection pickup on the distributor or on the flywheel. The flywheel sensors are know to have the wires break partway up the cable from engine movement, and when they go open the engine just stops. When the engine returns to a rest position they often touch back together and the car will start again. They are a pain to change, usually it means pulling the transmission since the sensor corrodes into the aluminum bracket.

Let me know how you make out.

Martin



Edited 1 time(s). Last edit at 09/11/2010 08:06PM by Martin Loveridge.

Martin!!!!!

How are you?!

Jeff and I will be at Pines again this year, but likely looking sad about not having a car ready...

The Justy will hopefully return next year, maybe for PN, but more likely a good old turn out at Bear.

The volvo wire harness is currently on my living room floor... The injector harness is a mess, bare wires for the temp sensor. Hopefully this is the problem.

Good to hear from you, are you still driving your volvo? (I think you had a white 240???)

Matt

White plugs, pinging, hi idle and missing can all be symptoms of an extrememly lean mix. As Martin mentioned the air inlet tube can crack or split causing lean mix from unmetered air entering the cylinders. Some cars seem to have grounding issues with a MAF and adding a dedicated gound wire seems to be a solution. If it has an airflow meter disregard the last suggestion.

Sounds an aweful lot like a BIG vacuum leak to me...

Good trick I found was to use some mechanic stethescopes, remove the metal rod part, and just use the open tube - it makes it real easy to hear the rushing air into a leak...

Found this trick when having a company truck sorted out after an engine R&R that I didn't do. Gave up on getting it to run properly and a local dealer had a look. He did everything I did - then did the stethescope trick and found a missing pipe on the back of the intake... Plugged the hole and it ran perfect.

Truck ran exactly as you described... (FI 302)

Rabin

Yes Matt, still a plethora of Volvo's around here. The daily driver is still the white '93, 487,000 Km now. I have some harness bits around here, let me know if you need something. If you need a drawing, I can scan and send you one.

I should be working at Pines as well, hopefully we can catch up then.

Arrgh!

Well that was a waste of a weekend!

Wire harness completely disassembled, repaired and replaced. Gene, there was a dedicated ground from the MAF, seemed stock and was in good condition. I didn't think I should or could do more? The wire harness I scrounged from the wreck yard did not have the same ground (was the newer LH 2.4)

Over the intake with a fine tooth comb, no vacuum leaks, no cracks

Re-gapped plugs

Fired it up same problem.

Out of curiosity I pulled out the cat and replaced with a straight pipe, still no change (but a bit more power...)

It still hunts terribly, but pings less or not at all around town. To tired to take it out to the highway.

The fuel supply seems fine at speed, given the above, but should I be checking fuel pressure?

Thanks for the help folks.

For sale:

Rust free '85 240, lots of cool bits, but doesn't run worth a damn! (hmm maybe this is my next rally shell... )

Matt



Edited 1 time(s). Last edit at 09/12/2010 06:33PM by Mad Matt F.

Any chance the timing belt or distributor jumped a tooth??

Matt

Check the timing belt like Gene said, there is a description in my earlier post.

Check the resistance of the injectors, I had one once that was down to 4 ohms from the original 16 ohms. The extra load caused the brain to go into current limit and shorten the "on" time for the injectors.

Measure the voltage coming out of the O2 sensor, when it is warm it should vary between 0 to 0.7 volts if the mixture is right (yours isn't) It should hunt back an forth between rich and lean over a few seconds. If it is giving a rich signal that could be leaning out the mixture. 0.7 volts is rich, 0 volts is lean. Try grounding the O2 input to the brain and see if the mixture goes more rich. The O2 connector should be on the passenger side firewall below the wiper motor and it should have two plugs, a two wire for the heater and a single 1/4" slide in a rubber boot that is the signal.

Check the timing with a light, it should be about 12 degrees BTDC at idle.

Too bad you're an 8 hour drive away. We'd hunt this down pretty quick here.

Oh yes, one last thing. Some 240's had a fuse on the injection system mounted under the hood on the drivers side fender, an in-line plug in style in a cheap holder. These are a known problem and when the contacts go bad all kinds of running problems can happen. The contacts must go to a (relatively) high resistance and that drops the voltage to the brain. Replace the holder and fuse, you can get a similar unit at CTC for a few bucks.

Good luck.

Long shot, you may also want to check compression - I had similar symptoms in my Audi S6 20vt - Head Gasket had developed a break between cylinders...

Vittorio -

Quote
vbares
Long shot, you may also want to check compression - I had similar symptoms in my Audi S6 20vt - Head Gasket had developed a break between cylinders...

Vittorio -

Your Audi had some pop, this is an old Volvo, it goes more Pfffffff.ffff...ffft.
prolly not enough pop to blow a headgasket...

check that fuel pressure, I am still voting main pump, maybe fuel pressure regulator.

Bad gas/ intermittent water in gas?

I'm having a similar problem with the bad running and the high idle.

I just replaced my injectors and seals (leaks and bad spray pattern), unfortunately those injector seals didn't last and I have to replace them again just a few weeks later. Those definitely contributed to the poor running.
I also noticed that there is no signals coming from the CIS box (a little older car than yours) and I hope that its just a bad wiring connection. How is your car's FI brain?