Recently my gf's early 1990s Seat Ibiza broke down yet again. Last time I had to make some plastic fiddly bits out of epoxy for it because of leaks (the older parts had been brittle) but now things are sadly a little more complex. I'll take it from the top:

Initially the battery died then in her various attempts to start the car she flooded the engine and carburetor by pumping the throttle.

The car has been immobile for a bit shy of a month.

I finally had time so I changed the battery on it, then:

1. removed the sparkplugs, cleaned them up a bit and made sure they fired up in sequence, which they did

2. I opened up the carburetor and got as much of the gas out as I could, made also sure that gas did get there from the fuel line

3. used the starter motor to get the cylinders moving with the sparkplugs removed in an attempt to get any remaining fuel ejected from the combustion chambers

Whenever I try to start it up now with the air filter removed there is occasionally ignition happening in the venturi with flames shooting out (much to the alarm of passers-by), there is a kick from the cylinders but then it bogs right down.

Somehow I fear that an output valve is screwed up and one of the cylinders isn't playing game and retains it's unburned mixture thus bogging down the engine. I came to this "conclusion" because I remember in the past that there were days that upon starting the car only 3 cylinders were working.

What options could one have at this point apart from opening up the engine and going for the valves (which I'd rather not unless we haul it to the farm and rebuild the whole thing)?

EDIT:
Ah crap - wrong subforum again... shit - sorry - meant for Off Topic - I doubt this Seat is going for any racing any time soon...

Perhaps the plug leads are on in the wrong order?

Does the engine had a cambelt?, might be worth checking the cam timing.

Spark - Check
Fuel - Check
Air - ?
Timing belt/chain - ?
Could be a stuck valve.
The flames suggest that timing is way off. My POS Ford did that.
Only 3 sylinders firing can be related to a malfunctioning lamda sond. If your car has injection. My -95 Golf did that.


For the har har bit.
It's an old Seat...

It does sound a little bit like the timing belt has jumped a tooth or two (actually it sounds like more, but I don't want to scare you). If two plugs are connected back to front then that is like having the timing way way way out.

Methinks you need to check cam timing, ignition timing and plug firing order.

my cousin has the same car and it happened to her at least three times that the engine suddenly ran only on 3 pots, causing flame throwing and bogging Seems to be a typical failure for that model.

Like everyone else said, first thing I'd check is the timing, then start fiddling with the carb, making sure the air/fuel mixture is right.

I don't have any experience with a seat, but most american cars, I'd check o2 and crank position sensors too. Possibly a really melted/busted honeycomb cat thats all plugged up too.

Don't play with the carbs. Most people haven't got a clue, including mobile tuning companies. If you don't know WHY you're twiddling screws, and don't have the hardware to balance throttles and idles, then leave it as it is. The number of cars I've had to fix because the owner has either had a go himself, or got in a company to do it for him.

Thanks for the tips so far.

I am not about to fiddle with the carb settings, they were just fine previously, the only thing that happened was that it was flooded, which was taken care of with much diligence and I also made sure everything was clean in there. I checked the air, there is intake.

I'll go through the plugs and make sure they're in the correct order.

The reason I mentioned the stuck valve was because of the flame shooting out of the venturi - it sort of hinted that there was no output so after combustion the gas was shot right back through the input valve. But I guess wrong timing would do much the same.

So, I guess it's google/research time to find more about getting timing right in case it's more than just the plug order (which I am 99% certain I put back as they were).

In my experience tuning cars, this is almost always a timing issue. Most recent example; I replaced the bottom end of my Capri 5.0 with a block from a mustang, although identical in nearly every aspect the new one had a different firing order, I had flames shooting 3 feet until I realized the problem and redid the wires/gaps.

Good - I hope I get it right, the distributor is pretty simple - it's a cylinder with a T shaped arm spinning around and making contact with the leads so I doubt there's much I could see about that apart from making sure that it does make contact (which I did).

Actual mechanics, and others more knowledgeable than me, amuse yourself with my cunning plan:

According to what I read the most common firing sequence would be 1-3-4-2 - I suppose I could validate that by checking the cylinder head positions in relevance to the distributor arm. If it's off and not pointing at a lead when the cylinder appears to be at the top-most then I guess it gets more complicated and I have to check the belt. In retrospect, I suppose the smarter-than-me people who designed this thing will have provided with some sort of marking on the belt would they not? So perhaps there is a better/smarter way to figure out the timing/firing sequence and if the distributor arm is not in sync? If not, would it be prudent to use the starter motor to set the cylinders in motion for my tests or is there some other factor I am overlooking?

I suggest that before you do anything major you buy a workshop manual for the car. I've found that Haynes manuals are good.

About the timing.
Usually engines have timing marks on the block that need to be lined up with the ones on the gears the timing belt goes over. These are all explained in detail, with good pictures, on those manuals.
As a rule of thumb:
If the timing is off by one tooth, you get a noicy engine.
If it's off by two teeth, you get to replace your valves.
Not true on all cars, mind you.

Googling for "Seat Ibiza Firing Order" gave the following couple of links you might be interested in. I haven't read them, just very quickly scanned over the first. The second is a SEAT forum.

http://answerpool.com/eve/foru ... /f/834602692/m/1416042375
http://www.automotiveforums.co ... in/forumdisplay.php?f=975

In short 1,3,4,2 sounds correct. Visually seeing which contact the rotor arm (the T-shaped thingy) is on will help decide which connector goes to which plug. If you were local I'd pop down and help

Quote from March Hare :

I suggest that before you do anything major you buy a workshop manual for the car. I've found that Haynes manuals are good.

Yeah, that was my first online search actually when I had to do some electric work and find the reason it was overheating a few months ago. Sadly it seems that no such is to be found and I had to improvise (successfully - I found a leak in the hoses, remade the t-junction with epoxy after getting a cast from the original and rewired the radiator ventilator because it was shorting). Haynes don't seem to care much for SEATs (no surprise) and I'll have to dig around more before I decide to tackle the full rebuild - more for the project itself than the value of the car really.

Quote :

About the timing.
Usually engines have timing marks on the block that need to be lined up with the ones on the gears the timing belt goes over. These are all explained in detail, with good pictures, on those manuals.
As a rule of thumb:
If the timing is off by one tooth, you get a noicy engine.
If it's off by two teeth, you get to replace your valves.
Not true on all cars, mind you.

Thanks - I'll get the muck cleaned off as well as I can and see what I can tell compared to your description and some generic info I've found online.

Quote from tristancliffe :

In short 1,3,4,2 sounds correct. Visually seeing which contact the rotor arm (the T-shaped thingy) is on will help decide which connector goes to which plug. If you were local I'd pop down and help

Thanks for the links and the help offer - I think I had ran across them too last night, the SEAT forum I think was a dead-end sadly, everyone had those fancy new injection SEATs (tsk tsk).

Unrelated to the current problem (possibly) but somehow I have the feeling I'll have to learn about car carburetors sometime soon. I've tinkered with moped and chainsaw ones (which are much much simpler) but what I saw of this one while cleaning it sort of baffled me a bit (also had the fear of mucking up something accidentally).

Success! It lives - I checked the plug cables and they were in proper order, but:

Following the simpleton's practical mentality of "if it's flooded then just get the gas out" I used a large syringe with a wee rubber hose attached and sucked out gas from inside 2 of the cylinders, the other 2 appeared to be dry since I had removed the sparkplugs the day before and let it dry. Then I also redid all the plugs, distributor cap and anything else that looked suspect with some contact spray.

Sadly from my previous attempts to get it started the battery was running weak and I only have a charger for smaller lead batteries (up to 6 amps) so I asked a friend to come around, we put the jumper cables and tada! After a few attempts it started up.

And man did it shoot some smoke out of that exhaust... good thing is that from whatever small care it got the past 2-3 times I tinkered with it many familiar rattles and noises are now gone and the engine has a healthier sound to it (but by far not perfect - ingition is definetely not as good as I'd like it if it was my car and I can hear some tell-tale micro-pops in the exhaust).

So, many thanks for your tips everyone.