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Prv engine?

Jonny4

New member
Joined
Mar 16, 2020
Location
Arizona
How?s it goin I?m brand new on this forum and don?t really know what I?m doing. I have a Volvo 240 and a 78? 265 wagon with the PRV engine. I replaced both fuel pumps, fuel accumulator, fuel filter, cleaned out the mechanical injectors(they spray). I am getting fuel tobthe engine and I am getting spark to the engine. The car will crank but still won?t start and I?m stumped. Anyone know what it could be? Thank you so much in advance!
-Jonny
 
Good next steps to consider would be checking fuel and ignition timing, I'd suggest starting off with the ignition, and then looking into if somehow the mechanical fuel timing can be tuned. You've gotten the spark and fuel, now get them together;)

p.s. Volvo has a history of using various systems to retard/advance certain timing setups for emission purposes, if you have access to a manual getting an idea of how the whole system works will save you a lot of possible confusion later. I'm unfamiliar with the prv, but that should get you a better idea of where to start and/or if some vacuum system is working against you.
 
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Good next steps to consider would be checking fuel and ignition timing, I'd suggest starting off with the ignition, and then looking into if somehow the mechanical fuel timing can be tuned. You've gotten the spark and fuel, now get them together;)?

Thank you! I do have a manual so I will get to seeing if how that work! I was also thinking it could be compression, do you think that would have anything to do with it? It ran before I replaced the fuel pumps and did the injectors. Thank you for your help!
 
newbie

Hey welcome to the forums !!! About your wagon, Try dumping some fuel through the intake and check the sparks to see if they are wet. This is based on your comment that you have spark and fuel. From there you might need to check belt timing and compression.
Best of luck , you are in the right place.
DZ
 
Hey welcome to the forums !!! About your wagon, Try dumping some fuel through the intake and check the sparks to see if they are wet. This is based on your comment that you have spark and fuel. From there you might need to check belt timing and compression.
Best of luck , you are in the right place.
DZ

I did that and the plugs did come out wet. I tried it a few times to see if it was a one time thing it happened each time. Thank you for your help I will check both compression and belt timing which I honestly didn?t even think about:lol: thank you for the warm welcome!
 
It ran before I replaced the fuel pumps and did the injectors. Thank you for your help!

No problem welcome to the forum;-) Are you sure the injectors are getting enough pressure to crack under cranking, if it ran before and you did not touch anything else, I'd first double check my work there, before touching other stuff. Fuel filters are also sometimes directional, possibly that's something else to check, I know I've made that mistake before:-P
 
No problem welcome to the forum;-) Are you sure the injectors are getting enough pressure to crack under cranking, if it ran before and you did not touch anything else, I'd first double check my work there, before touching other stuff. Fuel filters are also sometimes directional, possibly that's something else to check, I know I've made that mistake before:-P


Okay I?ll check that thank you! And they should be getting enough pressure but I?ll make sure to check that as well thank you!
 
'78 PRV - I am thinking K jet (untimed) fuel injection??? As I recall from my brief period of owning a car with the K jet system, starting fuel delivery does not occur through the port injectors. The K jet needs significant air flow through the fuel distribution thing to get fuel flow through the port injectors and that is not happening during cranking. As I recall, the K jet was like the D jet and had a separate starting injector which was time and temperature controlled. Check the operation of that injector and its thermal timer.

That pretty much sums up my memories of the K jet system.
 
Take the air cleaner assembly off. Turn key on. Push the pie plate looking disc down. Do you feel any resistance? Do the injectors “sing”?
 
Just moving this to a better spot - no harm, no foul.

Welcome to the board :wave:
 
Once you have wetted down the spark plugs they are gas fouled and you need to clean the gas off them and then check the gap and make sure it is correct per the manual. You can use a brass wire brush to clean the plugs and get a bosch spark plug gap gauge.

I would also verify that you are getting spark all the way to the plugs. That and the suggestion of checking the cold start injector. Also be aware that this engine is very sensitive to vacuum/air intake leaks.
 
Welcome,
I have been wrestling a 1978 264 PRV for a year now. I would suggest like others have to ensure the ignition timing is correct and the cold start injector is working. I know when I first got mine I couldn't get it to start and found that the thermal switch, cold start injector, and frequency valve were all either not connected or wired wrong. After correcting this it would run, just very rough. Also, the auxiliary air valve gave me an issue where it wasn't opening to let in the extra air needed on start up. If the CO adjustment is off and if its far enough out of spec it could prevent start up. Wish you the best!
 
First thing to do in a starting problem chase is to use starter fluid to determine fuel or ignition. Runs on starter fluid gotta be fuel. Doesn't run look to ignition or other.

You are going to need fuel pressure test equipment shortly. Here is a homemade set thread: http://forums.turbobricks.com/showthread.php?t=289775

I assume with the pump/filter work that you have good gas in the tank.
 
OP if it doesn't run on ether it is ignition.

Pull the coil wire. Hold it 1/2" from the strut tower and crank with the key on. Nice hot spark that audibly makes a snap-snap-snap? If so it is making enough spark. Pull a plug wire from a spark plug. Philips screwdriver in the wire held same 1/2" from a valve cover. Get same spark or none? Ignition secondary parts are a common failure. Chinesium replacement parts look like OE but are dead right out of the box more often then not.

I have seen too many times the hose that goes from airflow sensor housing to auxiliary air valve get popped out.... Takes exactly one 'sneeze' in the intake for this to happen. Then Elroy gets to work on it and twists the CO adjustment screw until it idles. The car is given up on months later to be sold for next to nothing.
 
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'78 PRV - I am thinking K jet (untimed) fuel injection??? As I recall from my brief period of owning a car with the K jet system, starting fuel delivery does not occur through the port injectors. The K jet needs significant air flow through the fuel distribution thing to get fuel flow through the port injectors and that is not happening during cranking. As I recall, the K jet was like the D jet and had a separate starting injector which was time and temperature controlled. Check the operation of that injector and its thermal timer.

That pretty much sums up my memories of the K jet system.

'K-Jet' Continuous injection. One injector over each intake port. Volume of air 'sensed' (poorly by today's standards) by airflow sensor flap which operates plunger in 'Fuel distributor' to deliver fuel to injectors; corrected for engine temperature and O2 content in exhaust stream.
 
When doing the ignition timing note that the PRV #1 cylinder is the one at the firewall left side. A previous owner's ASE certified oil change technician messed with the gear teeth and vacuum timing of distributor and got it within 30 degrees but it still didn't run right for some reason.

Any results with the fuel or ignition test?
 
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