Need help on my 4g32

[allentot]

guys i really need your help right now, i am having a problem with my engine right now..ok to the topic,..
my engine (4g32 stock internals with single side solex 40) runs and idles smoothly without any problem at all but when i came from a long drive and shut it off i am having a hard time to start again the engine, i need to pump the gas pedal for a while to get it running again...and just to add, engine gets really hot right now and when i'm driving with a/c on or without it my rpm drops like the engine will die..
so the question is this, is the carb that is having the problem or is it my engine??
i've noticed this when i recently changed my carb into a single side solex 40...
i am really not good now when it comes with the jets of a carb
thanks

[tandanus]

My guess is that your original carb had a fast-ilde setup that was triggered 1/ When the aircon came on and 2/ When the automatic choke came on.
T.

[shuggy]

my guess is you have the stock fuel pump yeah?
is it only when you engine is really hot?
i had this problem and it was a pain in the ass

my fuel pump was getting vapor lock where the fuel pump heats up and the fuel inside vaporises causing the pump not to work, have to wait untill it cools to start again.. so i changed to a Facet pump and no more issues. next time the engine is really hot and wont start take off the hose off the bottom of the fuel pump and i bet it will be empty..

With the aircon thing yeah T is on the money at my guess, as the compressor puts strain on the engine and if there is nothing to compensate this on the carb then you engine will die. easy way out is just to put the idle up a bit.

good luck

[allentot]

@^^^ yes i still have mechanical fuel pump that i just recently replaced a few months ago..so do you think changing my pump into a electrical will help solved this?? and lessen the engine heat?
and yes it happens when my engine's real hot...i'm just wondering why my engine gets really hotter now compare before when i was still having a stock solex carb??
and just to add to the a/c thing, my engine idles at 1.4kRPM but still when it gets hot( with a/c on) it goes down to 6k RPM...
help me please, i'm really desperate now in solving this problem before it gets worst...
whats the best thing to do....?

[allentot]

next time the engine is really hot and wont start take off the hose off the bottom of the fuel pump and i bet it will be empty..

but my fuel filter has gas in it the last time my engine won't start...

[A112H]

Sounds to me like a head gasket, nothing to do with the carb at all. He is using the fast idle to keep it running, what he said was it will die without the ac.

engine gets really hot right now and when i'm driving with a/c on or without it my rpm drops like the engine will die

but when i came from a long drive and shut it off i am having a hard time to start again the engine

probably cooked it.

i need to pump the gas pedal for a while to get it running again

because the cylinders are getting wet once that pumps out it will fire.

engine gets really hot right now

because it is passing and burning coolant.

Let it sit over night, first thing in the morning pull all the spark plugs out and check if they are wet. Then crank the engine with the plugs out and see if coolant comes out of any of the cylinders. You can have a cracked head or blown gasket without the oil and coolant mixing.

[galant573]

Interesting topic, had my share of this vapor lock thing, thinking about getting an electric type soon.. What would be the recommended pressure for a factory single down solex/mikuni carb, 'coz I'm looking at this Facet fuel pump on-line & one has a 4-6PSI, 30GPH rating while the other one has a 2.5 to 4.5 PSI, 30GPH rating..

[allentot]

Sounds to me like a head gasket, nothing to do with the carb at all. He is using the fast idle to keep it running, what he said was it will die without the ac.

engine gets really hot right now and when i'm driving with a/c on or without it my rpm drops like the engine will die

but when i came from a long drive and shut it off i am having a hard time to start again the engine

probably cooked it.

i need to pump the gas pedal for a while to get it running again

because the cylinders are getting wet once that pumps out it will fire.

engine gets really hot right now

because it is passing and burning coolant.

Let it sit over night, first thing in the morning pull all the spark plugs out and check if they are wet. Then crank the engine with the plugs out and see if coolant comes out of any of the cylinders. You can have a cracked head or blown gasket without the oil and coolant mixing.

whoa!!! thanks for the tip, i'll check the plugs first thing in the morning...hope this isn't the problem...
any other ideas??
and to add again, i can't pull the idle down to 1kRPM without the a/c on...

[krohny]

i think either pump will cover you, carbies dont need pressure from the pump they just need a good supply of fuel so you should look at the flow rate more then pressure, and everyone will have a different answer on what pressure to run, i think anything from 2-8psi will work, i had twin dellorto's and had about 3 running to them and was fine, but my pump was like 120 or 140 GPH i think..

[shuggy]

yeh i had a 4g33 that had this problem really badly, overheating was causing vaporlock, and it all came down to an old radiator..

is the radiator original?

[75wagon]

so the question is this, is the carb that is having the problem or is it my engine??
i've noticed this when i recently changed my carb into a single side solex 40...

So it ran well before you changed the carb?
If so has it had the problem since you changed the carb or did it run properly when it was first put in?
What condition in the Solex 40 in ?(that is a Solex C40 I imagine?) Has it recently been rebuilt? Was it sitting unused before you put it on the car?

Sounds to me like a head gasket, nothing to do with the carb at all. He is using the fast idle to keep it running, what he said was it will die without the ac.

allentot, do you know how to check for a blown head gasket? It's certainly a possibility.

Dave...

[allentot]

@dave
my engine runs without any problem before we replaced the carb and the solex 40 we just put in was never been rebuild before and it was sitting in my friends garage for quite a long time...
regarding the gasket, i just finished this morning checking my plugs for coolant leaks and there wasn't any trace of it on my plugs and my exhaust isn't experiencing smoke or drips of water in its tip..

[allentot]

and to add dave, my engine heats up alot since we put the carb (solex 40) in it even in the first place...

[tango76hardtop]

Sounds like the carby is your problem seeings thats with the stock carby it was fine and problems only started when you used the solex 40. when a carby has been sitting in a shed for a while they tend to need a rebuild to run right, you should try rebuilding the carby and tuning it and use the stock carb in the meantime or maybe even swap and leave your stock carby on it.

[75wagon]

and to add dave, my engine heats up alot since we put the carb (solex 40) in it even in the first place...

When you put the carb on, what temperature sender unit (bottom of intake manifold) did you use? The one on the original manifold or the one on the side draught manifold?
If the temperature sender is different maybe this could explain some of the motor temp problem?
Also, the thermostat, is it new, old or same as what the car had before?

my engine runs without any problem before we replaced the carb and the solex 40 we just put in was never been rebuild before and it was sitting in my friends garage for quite a long time...

Have you checked the float level in the carb? and I also wonder the condition of the gaskets?

regarding the gasket, i just finished this morning checking my plugs for coolant leaks and there wasn't any trace of it on my plugs and my exhaust isn't experiencing smoke or drips of water in its tip..

I imagine you also checked for coolant in the oil and oil in the coolant? And for bubbles on the bottom of the dipstick?

Sorry, I have more questions then answers

Just added:

Sounds like the carby is your problem seeings thats with the stock carby it was fine and problems only started when you used the solex 40. when a carby has been sitting in a shed for a while they tend to need a rebuild to run right, you should try rebuilding the carby and tuning it and use the stock carb in the meantime or maybe even swap and leave your stock carby on it.

I was also wondering if it was worth changing the carby back to see if it fixed the problem? At least that way it may eliminate the new carb as the source of the problem?

Dave...

[allentot]

the sending unit we use is the unit that comes with the side draught dave...
and what if i remove the thermostat?? will it bring more issues on my engine??
no trace of oil in the coolant and coolant on oil dave...
and can you teach me how check the float level on the carb?? i'm not that good when it comes with carbies..

[shuggy]

hang on.. on your original manifold versus the new one, are all the water lines the same? like the one that comes out between 3 & 4, you havnt blocked it have you by any chance with the new manifold?....

[75wagon]

the sending unit we use is the unit that comes with the side draught dave...

Try changing the sending unit over so you still have the same one as before. The senders may be different? Worth a try.

and what if i remove the thermostat?? will it bring more issues on my engine??

I wasn't suggesting removing it (although if you did it would increase coolant flow), the reason I asked about the thermostat is, if it is old (and not been used in a while), then maybe it is not opening up fully? I would try a new one if you haven't already replaced it, they are quite cheap.

no trace of oil in the coolant and coolant on oil dave...

That is good, so it doesn't seem like a blown gasket or cracked head. On this point still, have you ever had the head off your motor? What condition is the rear water jacket holes in (behind cylinder no.4). My old head had them corroded and about every 8000kms I had to replace the gasket. The metal rim in the head gasket was rusting away and allowing coolant into cylinder no.4. There was no coolant in the oil, and no oil in the coolant. You could tell the head gasket needed replacing when you ran the motor with the radiator cap off whilst warm. The coolant would flow erratically, and was easily noticeable when the radiator cap is removed. It would start running hot and using coolant. It would idle a little rough, and was down on power. No other signs of a blown head gasket were evident. Not even coolant out the exhaust.

and can you teach me how check the float level on the carb?? i'm not that good when it comes with carbies..

Sorry, I'm not familiar with the workings of the Solex side draught carbs.

Dave...

[colta51]

and to add dave, my engine heats up alot since we put the carb (solex 40) in it even in the first place...

there is a hose that runs from under the intake manifold to the metal pipe that cums round the back of the block
if this is bent or worn out it will cause over heating baddly! you must hav a good flow thru all water hoses!
or is the block off you used to block the water line from the carb to the head leeking? just a few things i thort shood be mentiond....?

[allentot]

^^^ is this the hose near the alternator that is connected on a small pipe going aroung the back of the head??
if this is it, i saw droplets of water on hose but not that much..
@ dave , thanks and will try to change my sending unit..

[colta51]

^^ yes thats the one it goes around the motor and conects to the heater (If fitted) and to the bottem of the carby manifold if this isnt correct you will get over heating problems... if you can see sum drops of water you might want to inspect all youre hoses...?

[oldn64]

Ok , let us look at a few things.

1. Dont remove the thermostat all you will do is increase coolant flow and only cool cylinders 1 and 2 ,3 and 4 will miss out and the carby will experience the same issue.
2. You only have this issue once changing the carby, so is the temp sender correct or not.
3. Vapour lock occurs usually because of the latent heat from the top radiator hose is penerating the fuel line. Mech pumps and even electric pumps running at 3-4psi will still suffer the same issue because the heat will still effect it unless you can get it away from the radiator top hose. Vapour lock occurs because of the low pressure of the fuel. if you increase the pressure of the fuel then it will tend to not vapour lock as much BUT the carby will now leak past the needle and seat so it is not an option. This is why EFI will not vapour lock, due to the increase in fuel pressure. Make sure you have the plastic shield around the fuel pump as this is important.
4. I have a gut feeling that you have a lean fuel mixture and thus the jets or metering is not right for your motor. Seeing that the carby is the only thing you have change this would seem the most logical. Have you tuned the carby correctly and does it have flat spots, runs on or backfires?

Cheers