G'day, and 504gl economy issues!

[jocksjocks]

Hi guys,

Big G'day
I've been having fuel economy issues in my 79 504 gl, basically it absolutely chews through the fuel where I'm getting a couple of hundred k's out of a tank . Before I take it somewhere I thought I'd run it past you guys to see if there is anything I could rule out in the limited scope of this thread.
Car starts fine, runs smooth, accelerates fairly well, uses 98 octane fuel.
Smells a bit petroley after I pull into driveway and turn it off.
I checked and it has a solex carby, but i have no idea what type etc! The car doesn't stutter, or misfire etc, and it doesn't seem to leak any fuel when parked for extended periods of time.

Has anyone had similar problems and had any obvious remedies/checks that one can do to rule anything out?

Thanks heaps frogs,
Jock

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[peujohn]

My previous 504 had a petrol smell after the car was turned off. It was a bit thirsty too. The problem turned out to be a diaphragm (?) in the carby. Not 100% sure because Paris Jansen found this problem after I sold the (written off) car to him.

[robmac]

Hi guys,

Big G'day
I've been having fuel economy issues in my 79 504 gl, basically it absolutely chews through the fuel where I'm getting a couple of hundred k's out of a tank . Before I take it somewhere I thought I'd run it past you guys to see if there is anything I could rule out in the limited scope of this thread.
Car starts fine, runs smooth, accelerates fairly well, uses 98 octane fuel.
Smells a bit petroley after I pull into driveway and turn it off.
I checked and it has a solex carby, but i have no idea what type etc! The car doesn't stutter, or misfire etc, and it doesn't seem to leak any fuel when parked for extended periods of time.

Has anyone had similar problems and had any obvious remedies/checks that one can do to rule anything out?

Thanks heaps frogs,
Jock

Could be a petrol leak. Have a look under the carby in the block "webs" for petrol. Also check fuel lines and hoses, especially the small piece of hose connecting to the tank.

A jammed auto choke will cause excessive fuel consumption, but normally a very high idle as well.

Excessive fuel consumption can also be caused by a poor general state of tune and/or a blocked air filter or obstruction in the exhaust.

Before diving into the carby too deeply, especially if the car drives smoothly and has acceptable performance. I would give the car an electrical tune up, ie points, plugs check ignition timing, check air filter and check plug leads and plug "tubes".

504 Distributors are known to wear mechanically but normally they don't drive smoothly when very worn.

As a personal opinion, if the carby is the problem, I would not persevere with the Solex. I, and many others, have fitted a Falcon Weber (XE ute) which is a far better carby. They are easy to find and cheap to repair. If your car is a manual the conversion is very straight forward.

[robmac]

My previous 504 had a petrol smell after the car was turned off. It was a bit thirsty too. The problem turned out to be a diaphragm (?) in the carby. Not 100% sure because Paris Jansen found this problem after I sold the (written off) car to him.

Carby accelerator pump? Fuel pump? Diaphragm

[jocksjocks]

Cheers guys, I'll have a check tonight, ie air filter etc.
it's a 3 speed auto, which may make an xe weber a bit harder to fit?
As for rpm, 105 km/hr usually gets me 3500-3800 rpm. I'll take it somewhere to get a tune up(if it needs one) as i have no skills myself!

[robmac]

Cheers guys, I'll have a check tonight, ie air filter etc.
it's a 3 speed auto, which may make an xe weber a bit harder to fit?
As for rpm, 105 km/hr usually gets me 3500-3800 rpm. I'll take it somewhere to get a tune up(if it needs one) as i have no skills myself!

Yes, the kick down cable on an auto would need to be worked out. I've never done an auto, but on a manual it only took 3 hrs.

Other AFers may have done autos.

If you are within a reasonable distance of Brunswick, Paris Jansen has a specialised RWD Peugeot workshop.

Paris has a big range of used parts and is reasonably priced.

Paris is an AF sponsor

[jocksjocks]

Thanks robmac,
I've got his details now if I can't solve it sharpish, I was going to sell the car but I've been driving it more and am having second thoughts, I think I would seriously regret it. Just need to fix economy! 350 km from a tank would be a win!

[jocksjocks]

Ok, so something I've noticed, which may in fact be totally normal, is when i accelerate hard or up a hill, the fuel gauge gets 'sucked' back towards empty, then when i go back to cruising/slowing down it goes back to where it was(pretty much). If this isn't normal, does it mean that something is just letting loads of fuel into the carby etc?
If this is normal, I guess it's off to the mechanic!

[robmac]

Ok, so something I've noticed, which may in fact be totally normal, is when i accelerate hard or up a hill, the fuel gauge gets 'sucked' back towards empty, then when i go back to cruising/slowing down it goes back to where it was(pretty much). If this isn't normal, does it mean that something is just letting loads of fuel into the carby etc?
If this is normal, I guess it's off to the mechanic!

The fuel gauge reading relates to where the tank float is in relation to the fuel level.

It could be fuel sloshing in the tank, but normally their is a delay in the gauge responding.

Either way it seems unrelated to excessive fuel consumption.

[jocksjocks]

ok rob, no worries. a friend mentioned something about the butterfly valve? with the automatic choke, a problem he'd had in renault 4's and the like.
i've posted a few photos, as i am wondering if anyone can identify what type of solex carby it is? i'm clueless!
cheers

[robmac]

ok rob, no worries. a friend mentioned something about the butterfly valve? with the automatic choke, a problem he'd had in renault 4's and the like.
i've posted a few photos, as i am wondering if anyone can identify what type of solex carby it is? i'm clueless!
cheers

Sadly, the R4 is very different to the 504. R4s had a manual choke which had a flap operated by a cable which choked off the air to make the mixture rich.


You 504 has one of the better Solex carbys. It is a Solex 3235 SEIEA . You will notice a assembly on the LHS rearish of the carby with a water hose into the top and bottom. This is the choke assembly. It does two things. First to up the up the idle (by a linkage to throttle butterfly) and second operate a choking flap on the top of the carby to richen the mixture.

Inside the choke assembly is temperature sensing spring arrangement. When cold, the spring applies both fast idle and choke to the carby. As the car heats up hot water circulates around the spring mechanism and causes it to reduce the choke and idle up gradually. At full working temperature all idle up and choke flap is action is removed.

There are essentially two adjustments, one is a needle valve (brass slotted screw) that adjust amounts of coolant water flow, hence heating effect, this adjusts how the choke will be in operation for. Faster flow= quicker heating = less time on choke. The other sets the amount of fast idle and choke flap.

I'm blown away with how clean the carby is and this suggest that regular maintenance has happened
so the carby is probably OK.

You get car up to temperature, remove the top carby hose, and have a look check the choke flap is fully vertical (quite close to), this indicates the choke is fully off.

You have said the car idles normally so there is no problem with the fast idle mechanism.

Also think twice about adjusting anything on the choke they can be a real b!tch to get back to a correct setting.

If you contact me via PM I can send you a pdf manual.

[GRAHAM WALLIS]

Sadly, the R4 is very different to the 504. R4s had a manual choke which had a flap operated by a cable which choked off the air to make the mixture rich.


You 504 has one of the better Solex carbys. It is a Solex 3235 . You will notice a assembly on the LHS rearish of the carby with a water hose into the top and bottom. This is the choke assembly. It does two things. First to up the up the idle (by a linkage to throttle butterfly) and second operate a choking flap on the top of the carby to richen the mixture.

Inside the choke assembly is temperature sensing spring arrangement. When cold, the spring applies both fast idle and choke to the carby. As the car heats up hot water circulates around the spring mechanism and causes it to reduce the choke and idle up gradually. At full working temperature all idle up and choke flap is action is removed.

There are essentially two adjustments, one is a needle valve (brass slotted screw) that adjust amounts of coolant water flow, hence heating effect, this adjusts how the choke will be in operation for. Faster flow= quicker heating = less time on choke. The other sets the amount of fast idle and choke flap.

I'm blown away with how clean the carby is and this suggest that regular maintenance has happened
so the carby is probably OK.

You get car up to temperature, remove the top carby hose, and have a look check the choke flap is fully vertical (quite close to), this indicates the choke is fully off.

You have said the car idles normally so there is no problem with the fast idle mechanism.

Also think twice about adjusting anything on the choke they can be a real b!tch to get back to a correct setting.

If you contact me via PM I can send you a pdf manual.

Sorry Rob, it has an auto choke so is a TMIMA, not a good carby at all.
The earlier one (SEIEA) had the manual choke and worked a lot better, when you opened the secondary barrel there was a noticeable surge in power.
Graham

[robmac]

Sorry Rob, it has an auto choke so is a TMIMA, not a good carby at all.
The earlier one (SEIEA) had the manual choke and worked a lot better, when you opened the secondary barrel there was a noticeable surge in power.
Graham

I though the TMIMA were fitted earlier 505 only. If however this is not the case I acknowledge your wisdom and suggest a weber off a falcon be fitted.

That's strange anyway, because my 504 factory manual makes no mention of TMIMA?
It says SEIEA was fitted with both manual and later auto choke?

[jocksjocks]

Sorry Rob, it has an auto choke so is a TMIMA, not a good carby at all.
The earlier one (SEIEA) had the manual choke and worked a lot better, when you opened the secondary barrel there was a noticeable surge in power.
Graham

should i think about a replacement carby? cheap to buy/easy to find?

You get car up to temperature, remove the top carby hose, and have a look check the choke flap is fully vertical (quite close to), this indicates the choke is fully off.

should i leave the car going when i remove the top carby hose?

really appreciating the feedback guys

[robmac]

should i think about a replacement carby? cheap to buy/easy to find?


should i leave the car going when i remove the top carby hose?

really appreciating the feedback guys

I'd leave it idling to the test.

Paris may have a Weber (Peugeot factory fitted) which would be easier to use with the the auto kick down cable.

[GRAHAM WALLIS]

I though the TMIMA were fitted earlier 505 only. If however this is not the case I acknowledge your wisdom and suggest a weber off a falcon be fitted.

That's strange anyway, because my 504 factory manual makes no mention of TMIMA?
It says SEIEA was fitted with both manual and later auto choke?

The TMIMA was fitted to the 504 post twin carby model, late 1978.
This was the square port engine, the Zenith INAT was fitted in some markets but we alaways got the TMIMA.
It will be in the later model supplement section of the manual, Haynes I think.
Graham

[GRAHAM WALLIS]

The TMIMA was fitted to the 504 post twin carby model, late 1978.
This was the square port engine, the Zenith INAT was fitted in some markets but we always got the TMIMA.
It will be in the later model supplement section of the manual, Haynes I think.
SEIAI are hard to find so probably best to go for the Weber although they don't work as well.
The Weber is a better carby but not designed for the 2 litre Peugeot engine unless you can get hold of the very rare model that Weber sold as a conversion kit for the 504.
Graham

[jocksjocks]

maybe i'm better off seeing what i can do with the one i have and if that doesn't make improvement then i'll look at a replacement, such as the xe falcon one, but i'll look at the choke flap tonight.

cheers heaps guys

[Peter C]

You're right graham. The Haynes manual does specify TMIMA in the supplement.

[jocksjocks]

has anyone done a successful conversion with a minimum of fuss? would be interested to get a quick summary of any issues, even as simple as sourcing carbys in melbourne
cheers

[robmac]

has anyone done a successful conversion with a minimum of fuss? would be interested to get a quick summary of any issues, even as simple as sourcing carbys in melbourne
cheers

I've fitted a Falcon 34 ADM Weber to an 2 litre 505 engine MANUAL in a 404.

[Pug_405_Mi16]

When well tuned and in good nick there is nothing wrong with either the early 504 Solex or the later one also found on the 505.

I've had plenty of good experiences with the carbies and believe that it is usually pretty simple to sort them out rather then resorting to a back of axe fix!

Anyway just my 2cents worth

Ben

PS, I am just going through the process of rebuilding the solex on my '73 504 as it has become a bit leaky after nearly 40 years of service!

[jocksjocks]

some serious food for thought from all sides of the conversion/swap/keep and spruce up debate. i think the best thing to do is look at what can be done with the current carby, then if all else fails get cracking on a conversion to a weber. i might start to see if i can source a good condition xe weber. first ill maintain the status quo, then go from there...

cheers guys

[Morpheus]

I am seldom a fan of modifying from original. My time with 504's had no problems with the standard Solex carbies. I would suggest just finding the problem and fixing it rather than undertaking a retrofit. Poor economy IMHO is likely down to autochoke staying on. If "badly tuned" is the cause then the thing must be running like a festered eye and that should be rather obvious. A carby overhaul and a new set of plugs should fix it - providing there is not something more sinister afoot like busted rings or valves.

[jocksjocks]

that sounds like a good idea morpheus, i'll give myself enough time to sort through this before making any potentially headache-inducing decisions. cheers mate