My 1976 242 is hard to start. I lay on the key for 15-20 sec and it starts. After it starts it idles rough....engine bounces around (which may be the motor mounts)....and when accelerator is pressed the car stalls. It sounds like it is being choked out. If I press the gas REAAALLLY slow it wont stall, if I press the gas in normal acceleration....it stalls out. Im a virgin mechanic and just know the basics. I have changed the fuel filter, spark plug wires, spark plugs, distributor cap and rotor, and ignition solenoid. Im wondering if I may have a problem with my O2 sensor or maybe the cold start valve? The vehicle sat for a good year before I got it and started to fool with it. I love this damn car and old volvos period and want this classic back on the road!! I appreciate any help or questions regarding the problem! Thank you!

 

For a hard cold start first thing I'd check is the Coolant Temperature Sensor.

 

Thanks! I'll give that a shot. Im sure its something simple, I would like to avoid the $90/hr shop cost if at all possible!

 

clean the throttle body, the idle air controller, make sure the throttle idle switch is working, and check the ECT (engine coolant temp sensor) with a ohm meter at the ECU connector when the car is hot and when its cold (my suggestion is, get the car hot, test it, wait for it to be cold and test it again, that way you only have to dig the ECU out once and unplug it).

this is a k-jet car, so, thats the extent of my knowlege, I've primarily dealt with LH injection systems.

(digs up the greenbook for a 76)... oh wow. what ECU? hah, what do I know? I don't see an engine coolant sensor at ALL. Looks like there's a temp sensor in the intake manifold that appears to just be a thermostat, if its cold, the cold start injector squirts when the starter is cranked. period.

 

It has been quite a while since I have had a K-Jet Volvo but I have been driving K-Jet VWs for the last few years. There should be a temp sensor with two wire that screws into a coolant flange. The first thing you should check on K-Jet though is the fuel pressure. It sounds like it might be to low if it dies when you hit the throttle. All throttle does is open up to give it more air. As more air is drawn in it moves the flap in the air box and and the flap moves the metering plunger in the fuel meter allowing more gas. I'm thinking it is leaning out when you hit the throttle. If the pressure is to low you most likely need a new fuel pump since you have already replaced the filter. Then again I would check out the fuel line, for kinks, from the pump to the engine also. This should help http://www.k-jet.org/articles/inform...jet-in-detail/ it is about Volvo K-Jet.

 

this is EARLY K-Jet, not later KE-Jet. my 84 and 89 VWs both had KE-Jet aka CIS-E.

 

Refresh my memory, does that just mean it doesn't have an O2 sensor system? This wold mean no frequency valve so the whole system pressure is controlled only by the warm up regulator that should be bolted to the block somewhere. To me KE-Jet means what VW was using on the late 80's Golfs and Jettas when they added a knock sensor.

 

hmmm. wiring diagrams for 1976 US model B21F show no signs of any o2 sensor ('lambda-sond' in volvo speak), or idle regulator ("CIS" aka constant idle system, not to be confused with CIS aka continuous injection system). that stuff was all added a few years later?

says tank pumps weren't used in production until 77 although some earlier cars may have been fitted with them.

 

How old is the gas in the tank?
Any tears in the throttle boot?

 

One of the major improvements was the introduction of the oxygen sensor in 1976 (1977 models), which Volvo called Lambda Sond and developed in conjunction with Bosch. Your's has one

I have a 79 242 "FEDERAL" model with no ac.....if you have ac you have a California model.

1) replace your O2 sensor...will idle super smooth...
2) use 4oz of Marvel Mystery Oil...to a full tank...let it run....see if it jerks/runs rough once at 1/4 tank.
3) engine mounts and transmission mount....my engine swayed like a Japanese skyrise in Armageddon....easy job.

your culprits on hard stars are:
Thermal time switch (back of cyl head by intake manifold)
Cold start injector
Warm up regulator........and nothing else......if your fuel pump relay is ok and pumps ok...

other problems I've encountered are:
bad resistor....under coil
Alternator bushing to block missing...not proper tension on belt...no turn sigs and screws up cluster.
bad Alternator ground...from alt to fender well
EXTREMELY BAD FUEL RELAY.....bought a cheap one and ran smooth for a week then relay quit on me....bought a OE for 15 bucks(used) have not had a problems...

BUY THE CHILTON BOOK ON EBAY FOR 9 dollars VOLVO 1970-89....WORTH IT....LOTS OF PICS OF YOUR K-JET. covers 1800 to 760's...very nice book....
DON'T PANIC THIS SYSTEM IS ACTUALLY VERY SIMPLE AND I FOUND OUT BMW'S AND RABBITS HAVE MANY IDENTICAL PARTS YOU CAN SWAP....CERTAIN YEARS OF COURSE NO LATER THAN 84

 

I have an '76 244 and can state without equivocation that this is not a lambda car. In dubberspeak, this is CIS-basic. Early 80's or Canadian later if you swing that way.

This system operates off of fuel pressure. First, eliminate bad gas and vacuum leaks. The cold start injector can cause the symptoms you speak of, either from leaking or from not getting the signal from the thermo time switch. Remove the connector from the cold start injector and test for 12V when the starter is activated. if no, it is bad wiring or a bad thermo time switch. If yes, remove the cold start injector (get a new seal first), remove the coil wire from the center of the distributor and connect it to the block, then have someone turn over the engine while you hold the injector over a glass container. It should spray for 12 seconds with a cold engine. Afterwards, it should not leak. If it is none of those things, there are more exotic fuel pressure tests and air plate tests. The absolute best manual for this car is the Haynes 1974-1980 owners workshop manual.

There is also a good chance your injectors could be clogged. They can be tested in the manner of the cold start injector (get new o-rings first). You can lever out each injector with a screwdriver or similar braced against a block of wood. Note spray pattern as well. With a new o-ring they just pop back in.


* There are '74-80 Haynes manuals on amazon for $1.98+ shipping- act now.

 

he has a 76, you just said lamdasond was introduced in 77 models, then you said he has one.

 

check your exhaust manifold....best way to know......and if you need to take it out....warm up the engine and use penetrant oil....mine was stuck on there pretty good...

send some picks of the body and engine bay...

 

My engine is doing the exact same thing. I'm curious to see what the problem is so I can fix it. Have you done a compression test to see if all cylinders are proper and even? My best guess is improper ignition or fuel delivery. My Volvo 850 had the exact same engine stuttering when I bought it where it seemed like under load it would stall out and that turned out to be an injector connector not being fully connected. Plugged it in and the car ran perfect after that.

Unfortunately these motor aren't quite the same so I'm in the dark. I'm just hoping we both don't have compression issues.

 

Just so we are perfectly clear. I own a 1980 242 GT and there is in fact an O2 censor located on the exhaust manifold right after the 4 sections merge into 1 on the firewall side.

A single wire runs to the harness attached the the firewall directly above where it connects and runs across the firewall to the driver's side.

 

your cold start injector is connected to the thermal time switch...check the wiring