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F5A Problem (engine died while driving)

35K views 8 replies 5 participants last post by  JamesGeorgie  
#1 ·
I have a suzuki multicab with F5A engine. It always ran well until last week. I'm driving from work when it started to sound and behave like the engine is not getting enough fuel. Rather than accelerate when you press the gas pedal, the engine sound will go down, choke then die :eek:. After a while, it starts again but will only run a few meters and will stop again the same way before. The same pattern went until the engine would only start but not anymore able to move the vehicle as it dies when you try to.

The mechanic have already checked the gas line, replaced fuel filter and fuel pump, clean the gas tank and carburetor. Upon replacement of fuel pump, it ran smoothly for about 20 kilometers and the same problem came back again :mad:.

Is there anyone who knows or have idea on the most possible cause, and solution to this problem? Please help me :(. Thanks.
 
#3 · (Edited)
I second that motion! You have eliminated the possible fuel supply problem, now it's almost certainly a clogged carb jet. But before assuming that- disconnect the fuel line at the carb, point the hose AWAY from the engine (at the ground if possible) and turn on the key. If the fuel pump is electric, the gas should shoot out like crazy. If it does not, then either the pump system is defective (it is possible that a surplus replacement can be bad) or your pump is mechanical. If mechanical, then you will need to crank your engine to get the gas to squirt.

I have seen a car that had a little leaf in the gas tank- the car would stall periodically, then magically start and run fine. After overhauling the whole carb, etc, they found the leaf in the tank and that fixed it. So you may want to check the tank again with a flashlight. Even if you swish the gas around to clean the tank the object can stick to the side of the tank and not come out when you empty it

So if the gas does not quirt out of the hose, don't just automatically assume the pump is bad- maybe something is blocking the intake intermittently

I have also seen a slime, looks like greenish-brown algea inside the float chamber of carbs. Also gum can form in there. Any of that stuff can break away and float around, periodically getting stuck in the jet. When you stop the engine, the object dislodges, only to do it again later.

Hope that helps
Craig
In the mountains of Cebu
2003 Suzuki F6A Drop-side pickup 4WD
 
#4 ·
I'm wondering if the OP ever convincingly solved this problem.
My F5a does the same. It had run perfectly for about 6 years.

Then about 6 months ago, it started intermittent dying. Sometimes ok for 20 miles, sometimes just one mile. Wait about five minutes and it would restart. Maybe keep going, maybe die again. Rev up ok in neutral, but die when in gear.
Over time, the problem got worse.

I thoroughly cleaned the tank, pressure checked the steel line, replaced hoses and filter.

At one time after this it wouldn't start at all, which was down to the fuel pump. I replaced it (could only get a surplus one), and it started and ran.....but the original intermittent prob was still there.

I stripped the carb (as far as I dared without a kit at the time), and as far as I could tell it was mostly clear. The problem persisted. And progressively got worse, till the vehicle became unusable.

I fitted a new fuel pump. The available new has an orifice bypass. Whether this is blocked or free to spill, the problem persists. I'd noted anyway that the carb needle valve spills via the accel pump for cooling once the bowl is full.

I got a replacement used carb. It ran fine...then the problem returned.

Incidentally, the replacement has a slightly different design. The original had an extra vac diaphragm on the bottom centre of the bowl, opening an additional jet. And a different needle arrangement. But when the vehicle ran, there was no difference in behaviour or performance between the carbs.

So what's next. I've obviously checked the plugs, points, timing etc. I'm 4 hours from the city (Cebu), but have just visited and bought a new (as in new!) coil in case it's breaking down. I've also bought a DB71 carb kit, and can strip it properly now.

And at least I've found out how to bring on the problem. If I drive on generally flat roads, it may be ok for various numbers of miles. But I've noticed that as soon as I drive up a 1 in 5 hill near here, the problem starts straightaway. After it dies, I have to wait. Then restart, and gingerly accelerate in neutral, and hope I can make a yard or two. Great fun.

I'm reckoning it's something to do with the main needle and piston or jets, and I'm xxxx! well going to find out.
 
#5 ·
Same thing happened to me. The mechanic put on another fuel pump but it had a cracked plastic housing over the electronics. He installed a USED surplus fuel pump! 3 days later it happened again. Luckily I was within walking distance to an auto parts store and bought a brand new pump for about 400p. I repaired both old fuel pumps and sealed the cracked housing on the second used one (water got inside and shorted it).
I keep those with me as spares. I would bet you 1000p he installed a used, surplus pump and it went just out again. Those fuel pumps are crap even brand new.
It's a good idea to flush your gas tank in case there is a leaf or something in there but if thats the case, the car will start right away and just stall again later at random.
Buy a NEW fuel pump. Examine the one your mechanic installed. Chances are it is a very old unit and just died on you.
Good luck
Craig
 
#6 ·
Your problem could also be electrical. Those vehicles are notorious for connections getting corroded or the high voltage system shorting when you spash thru a little water puddle. Make sure the ECM connection on the side of the distributor is sealed. Use silicone sealer if in doubt.

To check if the spark of your ignition system is shorting, spray WD 40 all over the distributor cap and park plug wires. If that fixes it, then it's time for a full tune up. New distributor AND spark plug wires. They will get fine cracks and short even with only high humidity.

One day my engine would not crank, for no reason. I just hot-wired it at the solenoid and it started. One day I decided to fix it. I just started wiggling and pulling on wires n the harness between the starter and the ignition switch, and suddenly it cranked again.

I suppose a connection got corroded and when I wiggled the wires around I got it to reconnect.

Regards
Craig
 
#7 ·
Thanks for your reply iesnes. All information is useful, particularly as the mightyboy manual which is often mentioned doesn't cover some stuff, like the carb and some electrics.

Anyway, I stripped the carb off yesterday. Of course, the rebuild kit was the wrong one. The place in the city said it suits all 6 valves, but when I looked closer is said DA not DB in rather faint printing. Should have checked and questioned that myself there and then.

Being somewhat fed up with the engine dying, I had a right go at the carb anyway. And guess what? I pulled out the needle valve seat, (a bit of a tug) and hiding underneath is a tiny strainer! I washed it onto a kitchen towel, and got a mess of tiny rubber debris.

Today, the vehicle behaved itself, including up the 1 in 5 a few times. It also was more tractable and smooth.

It's a possibility that this debris "unpacks" itself when the engine is stopped, and slowly repacks and eventually blocks. Also, the extra smoothness and tractability seems to indicate that I was not maintaining the correct float level before.

Fingers crossed.

I think Mikuni-san could have put his strainer in a more accessible and obvious position.

My next operation will be to try to replace the auto choke water-heated cylinder thing with a manual cable. Not that it's needed much in the heat here.
 
#8 ·
If anyone here is into British comedy, they may know Victor Meldrew and his reaction to yet another calamity.... "I DON'T BELIEVE IT!!!"

But here is a cautionary tale for all owners here.

After feeling reasonably happy that I was on the right track in my last post, the vehicle obligingly ran well.....for a few days. Then the same problem described above occurred. A few curses thrown at the thing didn't make any difference so I knew it was carb off, dismantle, clean internal filter.

This time, I was going to leave out that annoying internal filter and put an external one at the carb inlet. I found a steel Purolator inline one that would do the job.
Stripped carb....yes debris in filter. What? Everythings new or cleaned thoroughly. See above posts. Reassemble with new external filter.

Took for a test drive....ok for a few miles, then same problem!

Checked on the road....new (as in new)fuel pump output only occassional spits. Visions of a dud pump, cam worn, cockroach in the tank. Managed to crawl back home with some pushing too.

Checking through immediately, the hose from the chassis filter to the pump was virtually blocked. Took it off, just about got a wire through it. Cut it open. Then insides ressembled swollen plasticine with bits crumbling off.

The point is.....I bought the new hoses from an established parts store in Dumaguete. Unmarked, but that's common here. Rare to find SAE, BS or ISO markings with application. I doubt the store or even their supplier knew the construction of the hoses. Just believed them to be fuel hose.

A friend is going to Cebu city today, so will look for marked hose.

So be careful....stick to marked hoses whatever the store may say.
 
#9 ·
I encountered the same issue as the original poster.

My solution involved opening the floor "cover" of the engine to ensure normal airflow to the carburetor. I replaced the air filter and adjusted both the air intake and idle mixture of the carburetor.

However, the best approach is to clean the carburetor thoroughly.