1987 245 with a hard or no start cold. replaced fuel pump relay, not it. fuel pressure ok. does any one know what the specs are for the injection coolant temp sensor. Thanks, Jim.

Hi,

Can you tell us where you are with past troubleshooting?
Timing belt to no sparks are a real no starter!

There lots of things that cause no starts but you saying “when cold?”
Are you running Rich or not getting gasoline to the cylinders? Did you check plugs for a condition reading?
When you Check the AMM, as the other post suggests, do it while connected.
You want to see 12 volts on the orange wire as this feeds the injectors from that system relay, that you replaced. That relay does two functions besides the pumps.

The specs for the sensor area in the Bentley manual and of course, temperature dependent.

There is this post on the BB from Art that gives voltages and resistances on the ECU pins by back probing while is getting warmed up. It’s very helpful.
https://www.brickboard.com/RWD/volvo/1655709/220/240/260/280/ecu_suspect.html

I can say that if the problem just jump up in front of you. it might be the best way to go!
Because if it’s a wiring harness problem, you are in the middle of the circuit and can see it changes happen if the wires are wiggled.
A clue is if the wire is off the sensor, it’s a very high resistance to the program and it will think the car is in Siberia! (:/)
I think these cars even had a cold start injector? Could be leaking?
You see, lots of causes.

Worth a shot!

Phil

Firsr things i checked were for fuel and spark both. all cheked out ok. did find a bad coil wire and thought i had it. no such luck. Going to replace the injection coolant temp sensor. Also going to clean it up real well and fix the oil leaks.It 's leaking pretty badly. Could have something to do with it.

Hard starting when the engine is cold, but starting and running fine warm is a sign of a failed coolant temp sensor, so you are probably onto something there. If it has failed you may also see unusually low readings on the temp gauge. As far as oil leaks are concerned, first clean or replace the flame trap (aka PCV system), clean up the engine, and see if the engine still leaks oil.

COLD--not start

take off the cnxtion to the AMM---see if it starts without.

Report results

yes.unplugged it and still started and cont. to run.

hotbike650,

Does a silver hose connect the exhaust manifold heat shield shroud to the bottom of the air filter box? What region do you reside in?

If not emission control device inspection happy state like CA or NY, replace the air temp thermostat that is part of the air filter box flap valve or remove the silver accordion hose and remove the air filter box thermostat. You can choose to block ait filter box lower intake port. (I did not block it as I'm in pollution happy MO-state, the toilet. Yet my 240s will pass emissions in CA, WA, NY, OR and elsewhere.

I'd preserve the preheater function if you reside in a cold climate.

IN the air filter box is a preheater flap valve to blend ambient temps with heated air coming from under the exhaust manifold heat shield. A few years in hot summer will bring ruin to the AMM / MAF. You can test the AMM / MAF for voltages and futz with the AMM / MAF CO adjustment screw, I guess, unless Art Benstein says no.

You have the Chrysler MPG ignition. The ECU computer box is attached to the washer fluid mnetal basket frame.

I've not ever owned a 240 with LH-Jetronic 2.2 and older LH-Jet. If you have an electric digital multimeter, you can test connected sensors and devices as LH-Jet 2.2 and older has no OBD to relay engine control fault.

Also, 1987 is the final year of the rotting wire insulation harness? Inspect the wire harness for failing wire insulation in on the exhaust side of the engine and behind the engine.

Though a CeeBee guided you your AMM / MAF probably the fault after sometime of hot air only in the summer time passing through that AMM / MAF.

Thing like MAF's you want known good spares on the garage shelf and in the boot, fuel injection relay, spare fuel pump relay, spare ignition control module (thing obscure by the battery that amplifies the spark signal from the ignition ECU and send it to the ignition coil.

Find the Mitchell Service wiring diagram here for your 1987 240:
http://www.v8volvo.se/mekartips/volvo/index.html

Questions?

Hope that helps.
--
Beh.

so It Started with the AMM UNPLUGGED--- and ran.

When you unplugg the AMM you are now in what is known as the "Limp-Home Mode"

the FI computer is no longer getting a signal from the AMM -- it goes into the default mode.

Which means you have a bad AMM

There is plenty of Info on this Site about that---- Do a search --- failed AMM, Limp Home Mode, How an AMM Fails, Why AMM fails------as Keywords.