As it's gotten warmer in the pacific northwest my coupe has been breaking down. About a month ago its relay began turning off the fuel pump after about five minutes of idling. The amount of time it'd idle before dying varied with the ambient temperature and the amount of time it'd been driving. After dying the fuel relay would not click for twenty minutes or so. The car always had a weak main pump and a dead in-tank pump so I replaced the main pump and the relay, deciding against replacing the in-tank pump. The car's run for nearly a decade without it, the long-time previous owner was as lazy and afraid of messing up large projects as I am.

After that, the inability to idle without dying got worse as the temperature rose. I don't regret replacing it though, the old one caused pressure problems I'd previously attributed to it not having an in-tank pump. But just after replacing the pump, it died for the first time while driving instead of at idle. It began to buck and backfire and the needle on the tachometer bounced up and down. After that the relay refused to click for twenty minutes. It did this on three different relays, which led me to conclude something was killing them. Just this afternoon I got around to testing its voltage, at the switch with which I replaced the relay and having been idling for five minutes without dying it tested at 14.1v, 6.5a. If there are spikes in voltage they are definitely intermittent so I'll have to keep checking it.

With a switch in place of the relay it hasn't died at idle yet but I haven't really tried the thing. What it does still do is refuse to start hot before it's been cooling off for at least half an hour. The fuel pump is definitely running and I smell gas when cranking. I have not been able to check for a spark, there is rarely anyone around to help me with that when it's malfunctioning.

Here is a picture of him. I did not have a better picture.
Aüto


EDIT
It seems that the ignition cylinder has gone kaput. If it's the cause of the hot starting issue (providing a spark strong enough to run but not to start when hot) or even both problems (dies completely when hot, causes weird electrical feedback that prevents fuel pump relay from staying closed) then this is very convenient that it should choose now to die completely. It is worth noting that none of its pump relays appear to be dead for good, just they wouldn't work in the car for twenty minutes after stalling. Does this seem feasible and if that probable? Updates tomorrow.

 

without the in tank pump, the main pump has to work twice as hard, and is more likely to die.


what year is this car? is it a k-jet b21 or what?

 

1978, K-jet, B21.

 

I have no idea what's wrong now. It seems that the timing belt has jumped all of a sudden.

I traced the original problem to a bad ground in the wire that runs from the ignition control module to the distributor, once that and the damaged ignition control module were replaced, I cranked it and it backfired, puffed some smoke out of the intake manifold gasket, and began making that characteristic "i don't have compression in one of my cylinders" noise. Vvvvvt-vvvvt-vrrr-vvvvtt-vvvvvtt-vrrr.

 

re do the timing marks on all three pulleys...then crank it again....or you might need to adjust the "air flow meter plate"? On my 79 242 one of the three rubber grommets, the one attached to the fuel pressure regulator, next to the distributor had broken off and any little bump that I went over it would cut off...once I re-glued it with some epoxy (glued support, weird right) and adjusting the circle inside the air flow meter idle got better....but the compression sounds viable....as I recently had to replace the cylinder head....!!!!!!!!! as it had corroded beyond repair......

I had to replace my fuel pump relay as it was always very hot to the touch.....replace with el chepo one and it blew in a week...got me a used one and going strong.

 

Thank you for your reply c: My timing is cool. It took a while to get back to this thing, I had to work some double shifts. I think I have a bent valve, the intake valve must have stuck momentarily and got smacked by the piston. Looks like I'll be delivering pizzas on three cylinders for a week or two. That sounds terrible but my last Volvo was run for a year and a half like that before I got it.

To complain about my life for a bit, I told my boss this was a bad idea. He wanted to loan me money to buy an old Volvo with which I could deliver pizzas for him. He wanted me to buy an old Volvo because he knew that's all I knew how to fix. I tried to remind him just how long my last car was out of commission the two times it really broke down, but like all bosses he just told me he believed in me.

 

um, all B18,B20,B21,B23,B230 engines are non-interference (unless the head has been shaved more than spec, or they have a non-standard high-lift cam in them). this means the pistons CANT hit the valves even if the timing belt breaks.

have you run a compression test on all 4 cylinders? this would tell you if there's a problem in one of the cylinders like a bent/burnt valve (it wouldn't tell you WHAT the problem was, just that there is a problem).

 

Flat pistons mean interference, is that wrong? I'm still learning about these things. I changed the headgasket on my friend's '78 245, same engine, same year, flat pistons. I've done no compression test, a friend is coming with a gauge tomorrow. But it's definitely cranking like it's got no compression in one cylinder, just like when those people on Youtube invariably try to restart an engine that just died because they were attempting to destroy it, compression stops the starter motor three times then it skips. Also there must be some way for the spark to ignite the fuel in the intake manifold. The timing's fine.

EDIT: I should clarify, the reason I believe the valve couldn't be burnt is that this happened all the sudden, while cranking an engine that had not been run but cranked repeatedly for a week. It also was on old oil, and the thing was overheated by the previous owner numerous times, which could make a valve likely to stick, and strike this presumably flat piston. If I have a non-interference engine, than I've probably just got a stuck valve and my inspection of the valves today, which proved them to move up and down, indicates only that the problem solves itself after leaving the car alone for four days.

 

i've never seen the innards of a b21, but its descendent, the b230f, here's what both the valves and pistons look like...





thats an engine that blew its head gasket, and was overheated enough to crack the head (not evident in that picture).

 

Turbo engines, which you show there, have dished pistons which lowers the compression to avoid detonation at boost. The non-aspirated engines have flat pistons.

Either way, flat or dished, the engine is non-intererence and therefore the pistons should not hit the valves even if one is stuck open.

 

I would say the hot starting issue on your model 78 or 79? like my 79 242....

your thermal time switch is coupled with the cold start injector(I installed a new wire harness made by me and had to painstakingly undo wire by wire and thats how I know) .......my guess this is your problem and the fact your intank pump is toast....

therman time switch is on the last intake manifold port by the firewall costs New: 130 or junk yard

I HAD PROBLEMS WITH MY WIRING TO THE COIL....AND THAT WAS CAUSING PROBLEMS AS ONE LITTLE CONNECTOR ON THE COIL WAS MAKING LITTLE CONTACT...WIGGLED THEM AND VOALA...!!!! THIS AFTER NEW WIRE HARNESS AND GOD KNOWS EVERYTHING ELSE NEW ON IT...I THOUGHT IT WAS MY HARNESS BUT NO, THE CONNECTIONS ON THE COIL