for about 5 minutes or until it gets warm. I thought it might be the Engine coolant sensor, replaced that. Now it is a little better, but when it first starts it doesn't want to GO, it will move and respond to throttle, but feels like it's being held back. Then 4-5 minutes it roars to life and acts like nothing was wrong.

I'm wondering if it could be a cracked distributor cap that is getting some of this philadelphia humidity into the cap? The longer the car sits (let's say a week instead of 1 day) the rougher it runs when I get around to firing the car up.

Ideas?

 

How can you crank for five minutes without killing the battery? I would check a spark plug after cranking it a couple of times. They could be flooded with fuel and take five minutes or so to finally clean up enough and get a spark...

 

Sorry for the confusion burnstains. The car usually starts right up, but doesn't run smoothly and responsively for about 4-5 minutes. Then it runs like it has 30,000 miles on it.

 

engine temp sensor.

 

Is that the sensor between 2 and 3? I did replace that. Not very helpful, if at all, but I thought for sure that would solve the problem.

Is there a difference between engine temp sensor and engine coolant sensor? I replaced whatever was between pistons 2/3.

Thanks though for the suggestion pierce.

 

Here, I'm being lazy, but I really don't know much in this area. this is from these guys and what I would follow.Engine Sensors

Diagnosing ECT Failures. [Response: Don Foster, adapted to 700/900 series by Editor] Your engine has two temp sensors -- one for the gauge (it's mounted in the head about under intake header #2, and one for the FI (it's mounted in the head about under intake header #3). The latter is the ECT sensor.
The sensor is an NTC thermistor -- negative temperature coefficient. As the temp drops, the resistance rises, and as the temperature rises, the resistance drops. Thus, if you have a broken wire, defective sensor, or bad connection (I've seen it happen) the resistance measured by the ecu will be very high or infinite. The ECU interprets this as minus a zillion degrees and pours in the gas

The car I saw filled the oil with gas and certainly wouldn't run. And the problem was only a displaced spade lug in the plastic connector housing. According to Chilton's (you may choose to disregard this):

The coolant temperature signal to the control unit has a great influence on the computed injection period... For example, when the engine is being started and is cold, the amount of injected fuel must be relatively large. [Editor:] Too rich a mixture because of a failing ECT may lead to idle surges, high idle, poor warm running, or other symptoms of too much fuel. See Engine Tune and Performance; Symptoms for more examples.

If the control unit receives a signal higher than 302F (150C) or lower than -40F (-40C), it will interpret the signal as a fault...the control unit will assume a substitute value corresponding to 32F (0C) on starting and 68F (20C) when the engine has started.

With the control unit connected, connect a voltmeter across LH ECU terminals 13 and 5 (ground) for Bosch LH 2.4 systems or terminals 2 and 5 (ground) for LH 2.2 systems. This unit is in the passenger side footwell, under the plastic cover. Remove the cover of the large electrical connector to access the backs of the pins for the test. Turn the ignition switch ON.

At 68F (20C) the voltage should be 2.0 +/-.5v volts.
At 104F(40C) the voltage should be 1.2 +/- .3volts
At 176F (80C) the voltage should be .5 +/- .2volts.
The resistance values between ECU pins 13 and 5, or between each of the pins on the sensor and ground, are (by eye from the chart):

32F (0C)-- about 6000 ohms within a range of +/- 10%
68F(20C) -- about 2300 ohms
104F(40C) -- about 1300 ohms
140F(60C) -- about 600 ohms
176F(80C) -- about 300 ohms
212F -- about 190 ohms
[Response: Steve Ringlee] ECT resistance cold for LH2.4 systems should be around 6k ohms at 32 degrees F (0 deg C), 2300-2700 ohms at 68 degrees F (20 C), and 200 at 212 F (100 C). However, try checking your ECT wiring: Between pins 13 and 5 at the LH ECU (with sensor DISconnected) resistance should be infinite. Voltage with the ignition ON and sensor connected, measured between pins 13 and 5, should be:

0 C=around 3 volts +/-.5v
20C=around 2 volts +/- .5v
100C=around .3 volt +/- .1v
If these aren't correct, check the connections in the ECT wiring harness. Check engine ground connections at the intake manifold. If the voltage is zero, your ECU is at fault.

ECT Wiring/Connector Failure. [JonP] my 1990 LH2.4 still ran rich, smoked, stumbled, and set codes 1-1-3, 2-1-3, and others refering to rich mixture. However, during disassembly I discovered the female connector for the ECT was damaged by one of the sensors spade pins when someone pressed the connector on incorrectly. The pin missed one of the female clips and mashed it. The local Volvo dealer parts manager has been very helpful: I described the ECT connector problem and he gave a new connector to me with a couple of insulated pinch connectors and his tips for how to make the splice....no charge. He did say if this splice didn't fix it then he thought it was a failed ground in the ECU (ECM) for the fuel injection. He said the bad connector could also cause a bad ground problem at the ECU.

 

Burn stains, Thanks for the info you found. Good stuff and I'm still looking into it.

So last night philadelphia when through Irene. Wasn't too bad, lost power for about 12 hours, nothing major. BUT.... when I tried to drive the car it STRUGGLED to get going. I'd start it and the car would rev up, then stall out. Did that about 3 times immediately after starting. Then, it finally stabilized and would idle but wouldn't accelerate. Would just kinda putt around, almost felt like if I gave any more gas it would die. Slowly it got better and better and about 5 minutes later drove like nothing was wrong. Weird. Wondering if it had something to do with all the rain we got, and if the rain is getting somewhere.

 

I might be wrong here, but I think an 88 240 is LH2.2 not LH2.4. There's a number of differences, the 2.2 system is simpler.

that said, your symptoms almost sound like the air mass meter could be sketchy. thats the primary input that tells the LH computer how much air the engine is sucking in, so it knows how much gas to squirt in.

or as we said before, the engine coolant temp sensor, the one that goes to the ECU, not the one that goes to the needle on the dash. a cold engine needs a richer fuel-air mixture, once it warms up, the ECU leans it out. if it doesn't know its cold, then it could be trying to run lean when it starts. I believe the LH2.2 has a separate cold start injector, while the LH2.4 just opens up the main injectors more to do the same thing.

88 may be one of the years with bad "biodegradable" wiring. you pull back the sheath around a bundle of wires, and discover all the insulation underneath the outer cover is flaking off. bad juju. very expensive to repair.

 

Hey Pierce,
- 88 is 2.2
- MAF, when I unplug it while it is running, the car dies. Don't know what that means really, should I grab one from a yard and test it?
- ECT sensor was replaced. I'm 99% sure it was the one to the ECU, way hard to get to the thing under between 2/3 intake manifolds.
- I'm pretty sure that volvo had the biodegradable issue resolved by 88. At least that's what I've heard. I really hope that's not the issue here, but I would think that the car would have more issues than just at start up. Again, it's only when the car is "cold". Otherwise it runs like a top.

I'm almost wondering if it is the wiring for something like the MAF or the ECT sensor. I'll look into it a little more.

 

its supposed to be very bad to unplug the MAF when its running. can kill it permanently. key off, disconnect, key on, and it should run in 'limp home' mode.

if you have a compatible MAF to test with, sure, its easy to swap them.

oh, hey, does this car have the metal 'dryer hose' from the airbox to the exhaust headers? make sure the airflap in the bottom of the airbox is wired permanently shut. the thermostat in those dies and they stay open and let the car run on hot air which kills your MAF in short order.

 

The wiring was upgraded by Volvo sometime in '88, supposedly... Source http://www.nuceng.ca/bill/volvo/database/sources.htm#[HARNESS]
Humid air going across the film in the MAF can and should cause it to think it is really cold, thus dump more gas into it, so maybe some rain got into the intake with high winds??? Kinda unlikely since you say it gets better as time goes on, but just a thought.
They also note in the article where, if you have a bad ECT, it will eventually send a normal operating temperature signal and/or the ECU will take over and set a standard temperature for the fuel injection to work off of (it detects it as a fault so it doesent pour in the gas thinking it's below absolute zero). Basically, no ECT, the ECU takes over and sets it's own temperature. The quick diagnosis: Try disconnecting the ECT (after disconnecting the battery) and see what happens. If it acts differently, it might be the ECT or wiring.
The smart diagnosis: check all the voltage and resistance readings in that article, the ECT might be failing, and read cold until the car really heats up and the resistance finally drops.

 

Burn Stains, I love the avatar man.

Ridiculous. It's gotta be something with the wet weather. Or I'm dealing with 2 seperate issues here.

Today I came home and hadn't driven the car for 24 hrs, more than enough for the old thing to cool down I figure . It fired up and drove much better. No Stalling, no feeling like it was going to die. Still kinda sluggish until it warmed up a bit, but nothing like yesterday after the rain.

The rain seems to be the common denominator when this issue really makes itself known. I'll do the ECU tests as soon as I get some more time. In the meantime, anyone know where rain could be getting that would cause some issues? I hope the ECU isn't getting wet, but I don't know why the car would drive better after a while. I think I asked already but could a cracked distributor cap be causing the wet weather to condense inside the cap?

Another detail is that the car is parked on a 20-30 degree slope with the hood lower than the trunk. Don't know if that would matter at all, but thought I would throw it out there.

Thanks again for the help. Would love to get this figured out.

 

I'll get that wired stat. The car does have the dryer hose.

 

Hey thanks, I like it too. Plain yet sharp.

The drier hose could spell problems like Pierce said, eventually toasting your MAF if the flapper is in the hot intake position. If you are driving in rainy/humid conditions, that could be telling the engine to pour in the gas. Seeing you have the heater hose still hooked up, and it is most likely allowing some, if not all the hot air from the exhaust into the intake, the moisture problem would soon go away due to the intense heat.
Also, your ECU should not be getting wet unless you have a major water leak on your passenger fender well.

 

check your o2 sensor and wiring.