I am thinking about buying a Volvo from a guy that is about 3 hours from me. It is worth it to me non running but I would rather save the trouble of towing it by getting it running properly first. I've always wanted a 240 and this one is super clean.

This is from the seller

"Basically, it starts up great but after a couple of stops where I turn the car off, it will progressively idle lower. If I'm out for a while it sometimes will have trouble starting again. My mechanic said it might be the other pump. It seems to be something easily fixable, I don't have the time that's why I'm selling it as is. "
He says his mechanic replaced one pump but the one under the car. I'm guessing it might have a fuel pressure issue or a valve adjustment issue. I also thought about the fuel cap or tank breather might be plugged and its pulling a vacuum on the tank. I don't think these cars have a shrader valve to test the fuel pressure. What is the easiest way to install one? Should I plan on replacing the tank pump and also bring a high pressure pump also? I am mechanically inclined I just want to bring everything I need to fix it(as best I can anyway).

 

the fuel pressure test without the shraeder uses a T adapter, you unthread the fuel hose from the fuel rail, connect the T, and connect the fuel pressure gauge to that.

your symptoms don't sound like the fuel pump, they sound more like a funky idle air controller, or maybe coolant temp sensor.

 

Thanks for the input. The coolant temp sensor that is under the intake? I'm new to volvos.

 

I found this and it kind of makes sense. If the injectors are getting less voltage...

adio Suppression Relay. [What is the Radio Suppression Relay and where is it?] The radio suppression relay (as it's called) is in actually a fuel injector relay. The pre 1986 injectors were supplied constant + power to one terminal and supplied a timed ground to the other terminal via the ECM. The constant + power used to come from the fuel pump/injection system relay. In 1986 Volvo decided to isolate the fuel injector circuit because of some radio interference created by the pulsing circuit around the relay tray inside the passenger compartment and near the radio. The solution was to energize a relay - the radio suppression relay - with the pump/system relay feed instead of using the passenger compartment-mounted fuel injection relay to power the injectors directly. The radio suppression relay then supplies the + power to the injectors. The timed ground still comes from the ECM. The reason Alex can't find his radio suppression relay is because it's located on the other side of the engine compartment behind the power steering reservoir, (relay closest to the engine of the two relays mounted there Alex). For the most part the non-turbo engines had the radio suppression relay mounted on the right side (pass) of the engine compartment on or near the coolant reservoir or near the ABS unit. The turbo engines had the radio suppression relay mounted on the left side (drivers) of the engine compartment on or near the shock tower or the inner fender. Not set in stone just as a general rule. The radio suppression relay was used from model years 1987 until 1995 on almost all LH injected 4 cyl and V6 engines and many Regina cars. There may be a couple of exceptions. The 5cyl and straight 6cyl engines do not use one. When it's bad or missing, the radio will work fine, but the engine will not run. Remember even though it's called a radio suppression relay it's function is to supply + power to the fuel injectors.

Problem diagnosis:When this relay fails, it can cause:

• Hot start problems (car won't restart until it cools down)
• Failure of fuel injector system (no injector pulses)
• Backfiring or balky acceleration (insufficient or inconsistent injector pulses)

 

there's three sensors in the head under the intake manifold, I forget the order, but one is a flat thing with its plug on the side, thats the anti-knock sensor, one has a single pin, thats used for the coolant temp gauge in the instrument panel, and the third one has 2 pins, thats used by the ECU (fuel injection control unit) and ICU (Ignition control unit) to monitor how warm the engine is so it knows how much fuel to use and what the optimal spark timing is. its this last one that would affect engine running. they can be tested with an ohm meter, each pin is a separate sensor to ground (the body), the resistance is lower when the sensor is hotter, and higher resistance when its cold.

 

no radio suppression relay on a 240, thats a 740/940 feature, required because the 740's centralized fuel/relay panel brought the injection power too close to the radio.

 

As far as the temp sensor goes for the pcm is this true?

Volvo used 2 different senders; one for the gauge located under the intake by cylinder 2 and another, referred to as the ecs, located by cylinder 3. The gauge sender is further forward and easier to access than the ecs. The gauge sender being out in no way affects fuel mixture; it merely drives the gauge. It's possible the connector is merely loose.

 

Ah ok then I just have the fuel injection relay. I'm tempted to bring one of those, temp sensor, intake gasket, and a iacv with me. Much cheaper than a tow bill home.

 

I don't trust sellers. Sounds like a faulty Fuel Pressure Regulator but why idle progressively lower? Strange symptom! May have deeper problems... Hard to field repair a car for 3 hrs trip...

 

I ended up passing. I bought a 1990 with a ton of miles for next to nothing. It had a bad driveline shake. I fixed most of it with some new u-joints but it still has a pretty strong vibration during second gear(auto). I'm going to flush it shortly and change the filter. I also have plugs coming, wires, cap, rotor, timing kit, power steering lines, accessory bushings, trans linkage bushings, a few trans seals, and etc.

The car came with a full front end rebuild kit, all four shocks, and all of the rubber for the tops of the shocks.

 

Have you tried checking the mounts for all the driveline stuff including the engine? One or more might be bad with a lot of gap, and bam there's the slop where the movement is coming from.

 

I ordered all new mounts from FCP but they haven't arrived yet. Also have new washer parts on order. Hopefully the flush, filter, leak repairs, shifter bushings, trans mount, engine mounts, and etc will fix it. If not I'll start shopping for 5 speed parts.

 

Also this...

https://www.ipdusa.com/products/1005...ing-repair-kit

"

Product Description

A worn tailshaft bushing is a common failure in Volvo automatic transmissions that leads to fluid leaks and eventual clunking under load. Replacing the seal may stop the leak for a few weeks, but if any discernable play can be felt in the tail shaft, the bushing must be replaced to prevent future leaks and more serious damage to the transmission. It is necessary to remove the entire tail shaft housing to press out the bushing and press in a replacement."

 

I would try one thing at a time, going from the easiest to the hardest most likely problem. It's always saved me a lot of time and money...when I remembered to do that haha

 

Well the washer parts are for a different issue. They were missing all the external seals so I ordered new ones. The output shaft on the transmission is def leaking slightly and they say once that starts leaking the bushing is probably bad also. I know the engine mounts and transmission mounts are kind of rough.

 

For anyone who may read this thread about the original issue, check the throttle position switch!!!

My sisters 240 had the same problem. The motor idling slower and slower as it warmed up and eventually stalled. Had to hold foot on the throttle to restart Checked the throttle position switch for the idle circuit and found the switch had failed(open circuit). Swapped for a good second hand switch and the problem was solved.