Running on 3

[Pir0]

Started the car to get it outta the shed and down the road to my house today but it's just not running right

Symptoms:
Sounds like it's running on three, but in a weird way, not as if someones unplugged a plug lead, it sounds really lumpy, sounds like it's running on three at idle only, not as dramatic as one cylinder being not there altogether, sounds a bit fasster, and when you rev it it's still lumpy until about 2k then it's abit smoother but stil not running on all 4 properly. It also fires the odd pop down the exhaust manifold, or up the inlet. Some pretty beefy bangs, others small pops.

Checked:
Checked sprark, plug leads seem fine on all 4, havent took the plugs out just yet. Checked AFM, fine too, checked ecu, also fine. Tried adjusting my FPR and it was fine too.

I'm either thinking one of my injectors are blocked or it's something else altogether.

The reason I think it's the injectors is because I put in a dry tank, literally, barely any fuel, and the fuel pump was lying out of it while it was in storage for about a month and a half.. So i'm guessing some grits got in, a very small amount but it's possible. I only stuck a tenner's worth of petrol in and it barely lifted the needle, so couldit be possible it's just some of the dirt that was at the bottom of the tank?

But then again it was popping and banging the odd time so that kinda sways me away from thinking it's a blocked injector.


Anyone any ideas?

I've a set of leads, plugs, and a rotor arm here waiting for it. Dizzy cap aint old.

Bit dissapointed as I was hoping to have it in my driveway and tucked away for a while. Don't like it being in that shed anymore.

[daewoomofo]

that sounds like your timing is off, check how advanced/retarded your timing is.

[Spider]

that sounds like your timing is off, check how advanced/retarded your timing is.

+1 to that.
The backfiring is your clue here. Valve timing.
But, yes check your plugs first and make sure they are throwing healthy fire @ the gaps.
Unless you have bypassed the fuel filter? I kinda doubt that its your injector/s

Yes, you could have a bad one.. No CEL prior to this ? Check the voltage to each one or just use a test light as you crank the engine over. Process of elimination will eventually take you to whatever is causing this.
Hope you find it soon.

[Pir0]

Timings fine. Was timed properly Not long before i took the engine outta my old car. And it hasnt been touched since.

Nope, no CEL before this.
How do you check it with those lights? Never used one before.

Backfiring suggests to me, seeing as the timings fine, one of the plugs might not be sparking the healthiest. It is getting a spark fromm the plug leads, but I'm not sure. I think its not sparking enough some times and then there's unburnt fuel in the cylinder and it actually does get a good enough spark and ignites the unburnt fuel causing it to backfire?

[Spider]

Timings fine. Was timed properly Not long before i took the engine outta my old car. And it hasnt been touched since.

Nope, no CEL before this.
How do you check it with those lights? Never used one before.

Backfiring suggests to me, seeing as the timings fine, one of the plugs might not be sparking the healthiest. It is getting a spark fromm the plug leads, but I'm not sure. I think its not sparking enough some times and then there's unburnt fuel in the cylinder and it actually does get a good enough spark and ignites the unburnt fuel causing it to backfire?

If you had a valve that was not opening, hanging up, bent or a collapsed lifter ? you can get backfiring that way too.
I have seen this on motorcycle and automobile engines where the (adjustable) valves did not have the proper clearances. Too tight.
Your engine has hydraulic lifters (self adjusting) but if one goes bad your valve 'adjustment' is off. Got clean oil? filter ?

If you suspect a spark-plug or plug/s? Just pull them (one at a time) and check the gap/s, clean and reset and with the plug wire attached, ground (earth?) the spark-plug threads to the engine block and watch the spark jump the gap as your helper cranks the engine. Use safety precautions here. Don't hold the plug in your hand and No spilled gasoline allowed.
Your looking for a healthy bolt of electricity, bluish-yellow. Like a mini "lightning strike"

To test with a test light:

First buy a cheap one at your local auto-parts store. You want one that has the light inline with the current not one that takes a AAA battery. Just a cheap one. Two wires and a light. Take it home and experiment with it on your battery posts. Clip the black to the ground (earth?) post than touch the pointed probe end (red) to the positive post of your battery.
The light will light ! wooo000-whooo000 !.

Now do that to your injector positive feed (wires) one at a time as you helper cranks the engine. All this does is show you if the wire is flowing electricity. I always carry a test-light in my glove-box. you can test fuses (in-place) with it too.

[Pir0]

I'll try the plugs next time i'm up. I've new ones anyway, so I'll just wing them in.

Oil was just changed when the engine went in, as was the filter. Engine was dry for about... a week? As I had the sump off. But what difference would that make, as the car could have been lying up for a week and it would have had the same effect. So i don't think it was because of this.


If the spark plugs, leads, and rotor arm/dizzy cap doesnt fix it, i'll start into the heavier stuff like compression tests and then if needs be, take the rocker box off to check the valves, lifters etc.. Hope it doesnt go down this route.

[MMamdouh]

checked coilpack?

MMamdouh

[daewoomofo]

it has a distributor..... no coil pack

[Pir0]

What he said ^
:P

Surely you should know by now I don't ave daewoo engines, in my daewoos :P