Oh, and I will be doing everything here High-Mileage Vehicle Preventive Maintenance

Although tracking down a ball float for a DIY low coolant sensor is proving challenging. Any help on that is appreciated.

 

the blower motor is a pain in the butt to do, pretty much have to diassemble the whole dashboard to get at it.

noisy main fuel pump usually means the in-tank pump is dead.

 

Thanks Pierce, good to know about the fuel pump.

Fortunately the weather is still somewhat warm, so if I have to disassemble the dash it won't be as big of a PITA.

 

Read the whole thread... sorry I'm late to the party, especially as the car is bought. I just had one question: Has everyone gotten in the 18mpg range for the 740ts? The '89 740T I had got 24mpg new (Yes.... 20 years ago...the parents kept meticulous gas records), and these days is down to about 21-22 (Titan Joe has it now... he might be able to verify... but it was that way 2 years ago). The only difference is that it is a manual (M46). Everyone says the Turbos get worse milage... but my current NAS 240 '91 gets about 24. Are my experiences way right of the bell-curve?

 

I've seen 22-23 in my 92 745T on long highway trips where I drove like a little old lady for the entire tank at a steady 60-65, but I typically see 16-18 around town, depending on how leadfoot I'm being.

our 87 240 gets about 25 around town, and almost anywhere else, although I've seen almost 30 on a long road trip coming home from LA with a nasty hangover so I just cruise controlled it up I5 at 65mph.

 

Okay, that makes more sense. I sometimes forget that about all I do is highway or highwayish driving.

 

I manage to get about 21-23 mpg in city and about 27-28 mpg on the flat roads here (Ohio). I did do a drive from here to a little town north of Toronto, Canada. Averaged about 25.42 mpg and had some spirited driving at points, if that. This is on my 1991 244 with 268K miles on it.

P.S: Canadians were very surprised to see my brickbox rolling through downtown Toronto

 

So!

Got the new brick back, all inspected and ready to roll. Very happy with our purchase.

Question: On these NA motors, do you need to manually adjust the timing? The mechanic noted that the distributor looked like it could be loosened and adjusted, but I think I read that the ignition on these can't be advanced/retarded to any effect (the advance might be electronically controlled).

TIA!

 

what year 740? a LH2.4 car, the timing is completely electronic, using a pulse ring on the flywheel with a 'crank position sensor'. on an LH2.2 car, yes, the timing can be set by rotating the distributor. LH2.4 was on 1989+ non-turbo 240/740/940's and 1990+ turbos (except the Regina non-turbo 940's, they are a rather different setup but also use the crank position sensor for timing).

 

It's '89 740, so maybe it's an '88.5 (I've had 'in-between' year cars before, don't know if Volvo did this or not).

I'll check the engine badge when it's not raining. Almost certainly it's a LH2.4 though, I'm guessing.

Now you have me thinking maybe you could advance the timing by moving the crank position sensor, hmm...

 

no, you can't move the CPS, at least not without modifying the bell housing.

 

I actually thought that N/A cars had LH2.4 starting in 1988. The distributor in LH2.4 cars can move just the same as on LH2.2. The distributor casting is the same, the sensor (an plug) are not on the bottom of the LH2.4, and moving it just really doesn't change anything. So pictures will explain better:

Here is my 89 740 turbo distributor (it's for and LH2.2 system):



Here is an LH2.4 distributor on my 94 940 Turbo engine:



And just for reference here it is with the cap in place:


So you can see that they have the same slots on the side to adjust them whether or not it changes the timing. The 94 engine does seem to have a plastic plug just to keep people from moving it too far.

The quickest way I tell an LH2.2 car from an LH2.4 car is the mass airflow sensor. Here is a picture of my LH2.2 sensor:


The thing to look at it the plastic cylinder just to the right of the connector. There is an adjustment screw hidden in there on and LH2.2 car. LH2.4 does not have that screw, so the cylinder is not there. It's just a flat space next to the connector. So if the cylinder is there, you have LH2.2. If it's not, it's LH2.4.

Okay I just found my LH2.4 mass airflow sensor, so now you can see the difference:

 

the LH2.2 has MAF with a bosch number that ends in 007, while LH2.4 ends in 016

also, the LH2.4 cars have the diagnostic box on the left strut tower, while the LH2.2 don't.