Offroad-Express

Recently finished dropping a 5VZ motor into my Surf.

Initially we didn't have the fuel lines hooked up right and we flooded the motor a couple of times before we sorted it out.

Now that's all sorted, but it's not running quite right.

Sometimes it can be a little hard to start.

Other times, it starts but it idles quite rough, the engine shakes a lot. It even stalled on me once when it was in reverse.

When I give it some jandle, it runs smoother but I swear it's missing. Kinda hesitates.

When it gets warm, it idles just fine in Park but as soon as you put it in gear and give it a bit of gas it shudders again.

Any idea what this might be? I wonder if we fouled the plugs when getting it going. I've only driven it ~5km since it was running, should I drive it some more and see if it resolves itself?

bent valve or rod would be my guess

Have you checked the plugs to see if they are fouled up?

It might be easy just to replace them, modern fuel seems to foul them up real quick during the setup stage

what is the oil like does it have a strong petrol smell if so change the oil

I think I'll pull all the plugs this weekend.
I don't think it's toooooo serious as sometimes it settles down and runs sweet as. Pulls wayyy better than the old 3VZ when it's running right too

EDIT: Probably worth mentioning the petrol in it is maybe 4 months old and it hasn't had a petrol cap since about July. So it could just be really shit fuel.

SP450andLE wrote:Have you checked the plugs to see if they are fouled up?

It might be easy just to replace them, modern fuel seems to foul them up real quick during the setup stage

I second this, I've had this problem before with flooded plugs fouling.

boon wrote:I think I'll pull all the plugs this weekend.
I don't think it's toooooo serious as sometimes it settles down and runs sweet as. Pulls wayyy better than the old 3VZ when it's running right too

EDIT: Probably worth mentioning the petrol in it is maybe 4 months old and it hasn't had a petrol cap since about July. So it could just be really shit fuel.

Yeah, that could also do it, fuel goes off pretty quick. Although it is more noticeable in old cars, having no cap at all could make the fuel go bad pretty damn quick, so it might be time for a drain and re-fill

i think the whole 'off' or 'stale' fuel thing is pretty far fetched, i started up an old 4hp 2 stroke outboard the other day, hadnt been used in 7 years and it had 7 year old fuel in the tank , ran sweet, so i doubt 4 months is going to do a whole lot unless yourve got 4000hp

From wiki
Stability
Good quality gasoline should be stable almost indefinitely if stored properly. Such storage should be in an airtight container, to prevent oxidation or water vapors mixing, and at a stable cool temperature, to reduce the chance of the container leaking. When gasoline is not stored correctly, gums and solids may accumulate resulting in "stale fuel". The presence of these degradation products in fuel tank, lines, and carburetor or fuel injection components, make it harder to start the engine. Upon the resumption of regular vehicle usage, though, the buildups should eventually be cleaned up by the flow of fresh petrol. Fuel stabilizers can be used to extend the life of the fuel that is not or cannot be stored properly. Fuel stabilizer is commonly used for small engines, such as lawnmower and tractor engines, to promote quicker and more reliable starting. Users have been advised to keep gasoline containers and tanks more than half full and properly capped to reduce air exposure, to avoid storage at high temperatures, to run an engine for ten minutes to circulate the stabilizer through all components prior to storage, and to run the engine at intervals to purge stale fuel from the carburetor.[3]

vinceparts wrote:i think the whole 'off' or 'stale' fuel thing is pretty far fetched, i started up an old 4hp 2 stroke outboard the other day, hadnt been used in 7 years and it had 7 year old fuel in the tank , ran sweet, so i doubt 4 months is going to do a whole lot unless yourve got 4000hp

2 stroke engines would handle old fuel better, because of the fact they have the oil mixed with the fuel.

And 7 year old fuel is of better quality than modern fuel, so may not go off to the same degree.

Several time's I've had to replace the fuel in the tank of my Mini, as when left parked up for a few months, the 98 fuel has gone off completely

Ok, so I'll go put $20 of fresh petrol in it (it's almost empty) and if that doesn't immediately solve everything I'll pull the plugs and replace.

May pay to drain the tank first.

And run it for a while to get the old fuel out of the lines, and nice new fuel into them

Is that an air-flow meter type engine? Might pay to check for vacuum leaks, especially as you have just installed the engine...

pjb wrote:Is that an air-flow meter type engine? Might pay to check for vacuum leaks, especially as you have just installed the engine...

Yup. Found like 4 real small leaks, plugged them up, it's still missing.

Hoping it's just plugs.

It drips a little bit of petrol out the exhaust if I leave it running in 1 spot, so I would say it's definitely a miss.

Is it sparking all good? Could be leads or dissy (coil?)

mudlva wrote:bent valve or rod would be my guess

Got 6 nice new NGK plugs, old ones had a gap wellllll bigger than 1.1mm.
Runs great now

Goes to show it's the simple things that often bring up problems