[pete_79]

Sorry this could end up being a long one, I'm chasing a pretty specific issue with my G13ba and I think I've narrowed it down to the carby.

I've only just bought this car and it has been sitting in a shed for the last 2 years without being started. It's completely stock standard and was apparently a daily driver before being stored.
But it was running like a real bag of balls when I first got it. I got the line of "it was running fine when it got parked up, but must just have a bit of crap in the carby now".
So I have been fixing up all of the 'fixes' that had been done to the carby before and I'm now down to the last step which is what I assume they where trying to sort out with all that dogyness.

I'd rather avoid changing the carb if I can, it's such a specific issue that I'm pretty confident I can get it sorted with a bit of patience and hopefully some advise from the more experienced heads around here.

This is where I'm at now;
It starts fine (hot or cold), auto choke is working correctly, idles no dramas (at about 1100 cold and around 800 hot), it revs up pretty smooth (responsive to the throttle with no obvious misses or dead spots) and shuts down properly.

The issue;
It stops dead under load when in gear and feels like it's getting starved of fuel.
But it's only when under load, out of gear it's fine.

* It rolls off from a standing start while releasing the clutch with normal revs, but right as the clutch is fully engaged it stops dead, even when rolling down hill.
* rev it pretty hard and it has enough power to drive off, but even once moving as soon as I completely back off the throttle it stumbles and dies.

With a bit of practice I managed to find the right amount of throttle that it didn't stall and wasn't racing off. But it's a bucking bronco ride.
It's a really dramatic surging between diving normal for a second, then starved of fuel and just about dies for a second; then kicks back in and takes off for a second, then starved again, over and over.

What I've done so far, in order of completion (with test drives between most steps);
* Sorted a whole heap of dodgyness on the fuel cut off solenoid.
* cleaned out some gunk from the fittings and flushed out all coolent lines in and out of the carby.
* adjuster screw on the idle up solenoid wound back to where it should be.
* Throttle cable adjusted back so the warm idle screw actually adjusts something.
* flushed coolent system and refilled, set valve clearances and also fitted new plugs, leads, dizzy cap and rotor, then set timing.
* Pumped 2 cans of carby cleaner through it and revved it's tits off for a while.
* Swapped leads on plugs 2 and 3 and made a few good big spits back out the top.
* checked all vacuum lines, checked switch on the clutch peddle and checked sensors etc where all connected properly.

Tomorrows list;
* Drain fuel tank and fill with fresh 98, install new fuel filter and add extra filter between fuel pump and carby
* Oil and filter change
* use the 2m of vacuum hose that I bought today to swap over as many old lines as possible.

But after that I'm out of ideas.

Any suggestions for other things that could be causing such a specific issue?

[MrRocky]

Ive had a similar thing happen where the pickup in the tank was being blocked by debris

[HarryHoudini]

MrRocky wrote:

Ive had a similar thing happen where the pickup in the rank was being blocked by debris

Yeah,also check for crushed or blocked fuel line from Tank.
Emission era Carbies can be nightmare on all models & makes,i posted elsewhere about my Brothers 1980's Celica, 2 rebuilds from different Çarby 'specialists' didn't fix the problem,over a $1000 later we solved it by bolting on a Carby from a genuine wreck.
Good luck,hope you sort it.

[pete_79]

So is there any dramas with back-flushing the tank pick up from the line into the filter?

[MrRocky]

Take the sender and pickup assembly out the top of the tank and inspect the inside of the tank. I normally use vinegar and blue metal (stones) and shake the hell out of it for the duration of the day to remove rust and scale, then clean with metho and re-install

[Gwagensteve]

Fuel pump. These seem to last 21 years almost exactly, so you've had a good run. Fit a new SGP pump.
Agreed - check pickup and blow the lines through. Junk in the tank can cause horrendous and difficult to trace drivability problems.

Be aware the old pump has probably been dropping bits of rubbery goodness through the carby.

Confirm operation of the vacuum advance. No vac advance will give some of the drivability problems you're experiencing. It could be seized up.

Don't bother with 98 octane. It's harder to light so it places larger demands on the ignition system, which can exacerbate off idle performance problems. In any case, unless you add more timing advance it's just a waste of money - you're just burning the "extra power" down the exhaust not in the chamber.

[pete_79]

The saga continues....

So today it was;
*Replaced fuel filter, found the rubber hoses in and out of the main filter where pretty ratty so replaced those too.
* Connected a meter of rubber hose to the tank outlet line, then blew into the tank with the cap on and pressurized the tank. I let the fuel push back out. I did this a couple of times and was happy the pickup wasn't blocked.
* Checked all fuel lines from the tank to the carby, no other squashed lines or split hoses.
* Added the second filter after the fuel pump.
* Replaced all vacuum lines on the carby.
* Basic oil and filter change with new air filter (apparently the old one was installed in 2001 )
* One last squirt of carby cleaner just for good measure.

But....
No change to the problem.

This time I took it for a decent run on the road. It was surging and pulsing all the way through the rev range and at all speeds.

It's making decent power, had no worries going up hill at 40km/h in 4th gear. It just surged while doing it.

My heal and toe driving isn't up to scratch these days and I couldn't keep the revs high enough to grab first at intersections, so it stalled at every corner.

I'm thinking Steve is on the money again.

Gwagensteve wrote:

Fuel pump. These seem to last 21 years almost exactly, so you've had a good run. Fit a new SGP pump.

But I can't find any SGP pumps online. Heaps of fuelmiser around, but I've read plenty of reports in the last few days that these are noisy and perhaps not the greatest.

Any tips where I can get a decent replacement?

Repco retail at $248, I got a super special offer from the dude at my local store of $165. But had to order and pay today, I'm hoping there's better deals out there.

[Marko_SJ]

FWIW I think I have a Goss pump in my sierra. Maybe its the rattle/tick my sierra has. But it runs strong enough. My only carby woe towards the end of a few years of daily driving was the lack of a decent throttle return spring, the way around this was to tap the pedal and the idle would settle back nice and low.

Dumb question but have you tried a suzuki dealer for SGP?

[MrRocky]

U wont be able to check the condition of the tank or if the pickup gets blocked unless you drop tank, remove sender/pickup and check inside/drain tank

[Gwagensteve]

Agreed MrRocky. We had a car in the club years ago which had little pebbles of fuel tank putty in the tank. it would roll around and plug the pickup. Turn it off, restart it, and it would drive fine for 5 minutes. Or an hour. or 5 seconds.

$165 seems a little rich for an SGP pump but not out of control - I was quoted mates rates of circa $130 many years ago. Noise isn't the issue with aftermarket pumps, it's short life. A local suzuki specialist, who sells loads of cheap aftermarket stuff, won't sell an aftermarket fuel pump.

[pete_79]

Tank is on it's way out now...

Just had a quick look at fuel pumps online while having beer this arvo. Didn't really think the dealers would take my call on a Sunday arvo.

Will shop around during the week for a pump, but will clean the tank up properly first.

[sideways]

US$81 plus shipping for genuine. Google the part number and you might find other options.

https://www.megazip.net/zapchasti-dlya- ... l-89328205

See if someone will swap pumps with you. When my fuel pump died it did pretty similar but at first it was just like an ignition cut.

Checked the secondary jet is there/unblocked ect? It's easy to pull the jets out, there's bungs on the side of the float bowl.

[Gwagensteve]

I would have thought no secondaries would just make the car very flat, not surging, but still its worth checking.

Steve.

[pete_79]

sideways wrote:

US$81 plus shipping for genuine. Google the part number and you might find other options.

https://www.megazip.net/zapchasti-dlya- ... l-89328205

See if someone will swap pumps with you. When my fuel pump died it did pretty similar but at first it was just like an ignition cut.

Checked the secondary jet is there/unblocked ect? It's easy to pull the jets out, there's bungs on the side of the float bowl.

I'd be happy to run with this option.
That pump in your link is all good to go right?
Sorry I don't know the part numbers, but at $120 delivered for a genuine pump it's not worth messing around with eBay crap in my mind.

Edit;
Never mind, a quick google search confirmed that's the one I want.
Ordered and on it's way.

Got a couple of weeks to get the tank cleaned up and double check the jets.
Though it did backfire a couple of times through both sides of the carby when I swapped the leads, it's still worth making sure there's nothing funny going on in there.
At the moment it's still just a process of ruling out possibilities for me.

[losfer]

Disconnect the 2 wires going to clutch pedal switch. Cut off the sockets and join the 2 wires together. Seen this prob a couple of times.

Sent from my SM-G935F using Tapatalk

[pete_79]

losfer wrote:

Disconnect the 2 wires going to clutch pedal switch. Cut off the sockets and join the 2 wires together. Seen this prob a couple of times.

Sent from my SM-G935F using Tapatalk

So I could just pull the wires from the switch and short them as a test?

[Marko_SJ]

Gwagensteve wrote:

Agreed MrRocky. We had a car in the club years ago which had little pebbles of fuel tank putty in the tank. it would roll around and plug the pickup. Turn it off, restart it, and it would drive fine for 5 minutes. Or an hour. or 5 seconds.

$165 seems a little rich for an SGP pump but not out of control - I was quoted mates rates of circa $130 many years ago. Noise isn't the issue with aftermarket pumps, it's short life. A local suzuki specialist, who sells loads of cheap aftermarket stuff, won't sell an aftermarket fuel pump.

That is what my Sierra did when it had a blocked fuel pickup. Exactly as you say. 5 minutes, maybe an hour or play up immediately.

pete_79 wrote:

Tank is on it's way out now...

Just had a quick look at fuel pumps online while having beer this arvo. Didn't really think the dealers would take my call on a Sunday arvo.

Will shop around during the week for a pump, but will clean the tank up properly first.

Well it's Monday now. Either it'll be reasonable or outrageous. You'll know after a phone call.

Edit: sp.

[pete_79]

Marko_SJ wrote:

pete_79 wrote:

Tank is on it's way out now...

Just had a quick look at fuel pumps online while having beer this arvo. Didn't really think the dealers would take my call on a Sunday arvo.

Will shop around during the week for a pump, but will clean the tank up properly first.

Well it's Monday now. Either it'll be reasonable or outrageous. You'll know after a phone call.

$168 from Cricks in Maroochydore (in stock in Brisbane).

Megazip had a 10% off coupon last night, so it came to US$90 delivered (~ AU$120 at today's rates).

So there's $48 difference between having it tomorrow or in about 2 weeks time.
The difference was the cost of a new timing light, and seeing as I don't need my Sierra running as a daily driver I can wait for the pump and not have to borrow my neighbors timing light next time...

[MrRocky]

How was the inside of the tank ?

[pete_79]

MrRocky wrote:

How was the inside of the tank ?

I'll let you know later this arvo.
It was dark by the time I got the filler pipe off and siphoned it ready to drop out yesterday.

[Marko_SJ]

pete_79 wrote:

Marko_SJ wrote:

pete_79 wrote:

Tank is on it's way out now...

Just had a quick look at fuel pumps online while having beer this arvo. Didn't really think the dealers would take my call on a Sunday arvo.

Will shop around during the week for a pump, but will clean the tank up properly first.

Well it's Monday now. Either it'll be reasonable or outrageous. You'll know after a phone call.

$168 from Cricks in Maroochydore (in stock in Brisbane).

Megazip had a 10% off coupon last night, so it came to US$90 delivered (~ AU$120 at today's rates).

So there's $48 difference between having it tomorrow or in about 2 weeks time.
The difference was the cost of a new timing light, and seeing as I don't need my Sierra running as a daily driver I can wait for the pump and not have to borrow my neighbors timing light next time...

Yeah not to bad considering it's a dealer, rather than just an online parts shipper. I'm impatient and would like to know if that was the fix or not. Really, apart from your pick up there's not much left IMO. If you're patient... winning.

Speaking of which, I need to order some parts myself.

[pete_79]

MrRocky wrote:

How was the inside of the tank ?

Well apart from these weird little foil discs, it's actually really clean.



Unless I'm missing something, that pickup looks fine to me.

[MrRocky]

Ummmmm.... weird little foil discs haha wtf is that

[pete_79]

I'm guessing this is another reason why you shouldn't use additives in your fuel tanks...

The bottle top is just for scale.

[pete_79]

I didn't pay a lot of attention to the fuel gauge when I first got it, I'm pretty sure it was empty but the needle still moved. But I know it wasn't working after I dropped 10L in it the other day.

I've found Steve's old fuel gauge fix thread, but all of the photos in there are broken.

I think everything here is fine.
All parts move normally and the flat plate touches the coil all the way through the motion. But the gauge doesn't move...

[Blkfxx]

If you ground the sender wire, Gauge should read full.

[pete_79]

Blkfxx wrote:

If you ground the sender wire, Gauge should read full.

Thanks mate.
Just quickly tested this and it does read full when earthed.

[MrRocky]

Looks like sabotage

[pete_79]

I'm going to throw out my crazy theory here.

I recon whatever the fault is that I'm chasing now actually started a couple of years ago. Old mate (or his mechanic) had been chasing the same symptoms, they just did different fixes to how I'm approaching it. I think it got put in the too hard basket and he just lost interest in sorting it properly.

They've poked a heap of holes in the wires in the fuel cut off solenoid testing it and messed around with idle settings. Obviously those didn't work.

And judging buy how spotlessly clean that tank is, I'm thinking they also pumped at least 6 tubes of whatever fuel treatment/cleaner through it trying to flush the system to see if that would get rid of the surging.

I'm keen to get the tank back in and test the suggestion to short the switch on the clutch. It could end up being some little random thing like that causing the issue.

But at this stage I'm actually kind of enjoying this little fault finding exercise. Going through each step and taking my time to understand the proper functions and details of systems and components has been interesting so far. Bit of a short course Sierra apprenticeship.

But yes, I would still like to have it drivable sooner rather then later....

[Marko_SJ]

Cant really blame people for turfing the 1.3 for a G16B when faced with tail chasing like this.

Edit: here's a thought. Have you tried jury rigging a temporary tank first just to the carb to see if it runs right, and then to the fuel pump if the carb checks out. Might help isolate the issue?? If they both work it's your lines/pickup/tank vent/breather.