I recently changed my plugs and wires with NGK plugs https://www.autozone.com/external-en...084/505369_0_0 and the new wires are https://www.partsgeek.com/catalog/19...l?brand=walker . I am having trouble now though because I lost power, I can barely make up our slightly inclined driveway in first with a wide-open throttle. My two thoughts are these parts aren't right or maybe I need to tighten the plugs down more because I could be losing compression, any advice or thoughts would be greatly appreciated.

 

Spark plugs should be tightened down to compress the washer on them - don't remember how much, always did it by feel - maybe 20 ft-lbs.

If your spark plugs are loose, they will eventually fall out - but won't cause a substantial loss of compression until that happens.

 

Mine are pretty snug but I plan on going and giving them one more good quarter turn or so. If that isn't the cause of my rough running and loss of power though, any ideas on what it could be?

 

follow up: I snugged them down and triple checked everything and it ran a little bit better but now when I drive WOT in first up an incline I have a weird clunk from around my front axle... and it still struggles up a hill.

 

what year 240 is this? if its a 83-88 with the 'chrysler' ignition controller on the front inside of the right fender, just behind the headlight, check the vacuum line attachment at the bottom of said ignition controller.

if its an 83-87, also check the engine wiring harness for signs of cracking/flaking insulation around the individual wires (often inside the black outer sheaths), those years were notorious for 'biodegradable insulation'.

 

it’s a 1987, i test drove it today and it ended with my cat getting red hot and smoking so i’m pretty positive i’m getting unburnt fuel in my exhaust. i also didn’t have any problems before changing the wires and plugs so i feel like that’s the cause of my problem (i changed wires and plugs because i recently got the car and seemed like a good thing to change)

 

For what it's worth I recommend the Boughicord wire sets sold by ipdusa or fcpeuro or whomever....


Maybe you got a plug wire out of order?

 

that’s possible, i’ll have to mess around with that tomorrow. could you take a glance at the wires i linked and see if anything pops out at you as a problem? i looked at ipd wires but got those ones because they were less expensive (high schooler trying to save money where i can)

 

the ones you got are probalby fine.... the bougicord ones are closest to the original Volvo wires, as they made them for Volvo.

having the firing order wrong would make an engine run terribly, with no power.

make sure the distributor rotor is pointing to 1 on the cap when the engine is at #1 TDC

 

ive never worked on a distributer, could you explain what i should do a little more?

 

rotate the engine the timing mark on the camshaft is at the marker... then take off the distributor cap and note what direction the rotor inside is pointing, it should be to the #1 cylinder on the cap. then check all the spark plug wires to ensure the firing order is correct, 1-3-4-2 (looking down at the distributor, it rotates clockwise)

visually inspect the inside of the cap, and the rotor, there should be minimal signs of carbon tracking on the cap, the rotor should have minimal erosion. also many people neglect the 'disc' shield that is under the rotor, this should be renewed every (long interval) or when it looks like it has had carbon arcing. the cure for any of this is new rotor, cap, disc as needed, quality Bosch parts only.

after its run poorly for a few minutes, stop the engine, and pull out all 4 spark plugs, keeping them in order... compare them, is one drenched and not light grey like the rest? that suggests that cylinder isn't firing, maybe its a bad wire? poorly gapped spark plug (should be gapped 0.030", +/- 0.002)?

 

pierce my man, you’re right once again! i assumed the distributor would go in a circle but it’s more of a zig-zag. your diagram wasn’t the right one for my car because my distributor leads are a square and not a diamond when looking from the front of the car but i found one that was right for me and the car is now running like an absolute beast now, thank you so much!

 

yeh, #1 is often closer to the engine than as shown in that pic.

if the firing order was 1-2-3-4, an engine would be very un-smooth. its 1-3-4-2 so the pistons going up and down are balanced (when 1 and 3 are going up, 2 and 4 are going down...