4age - won't start

[nile]

Just replaced the head gasket on my big port 4age and now it won't start. I managed to get it running but it was only on 3 cylinders (by the sounds of it). I came back to it the next day and it wouldn't run at all.

So I checked that all 4 plugs were sparking and they weren't so I got the distributor cap, leads, and plugs from another working big port and put them on but it still doesn't run.

I've checked the cams are in right, the cam belt is right, and the distributor is toothed in correctly. I have also tried the timing at several different advancements/retard angles at the distributor. I can smell unburned fuel from the exhaust and the cylinders when the plugs are out. When I crank the engine by hand I can hear each injector going. Compressions are good on all cylinders.

Can anyone point me in the right direction as to what might be wrong? Everything I can think of I have ruled out, mostly because I have had it running.

[CAMB01]

Check to make sure your earth's are bolted on

[rollaholic]

did ya plug everything back in, im specifically thinking coolant temp sensor. is it still not sparking?

[nile]

The coolant temp sensor and cold start timing sensor is hooked up. I've also checked grounds to the head and cam covers and it's all grounded. It is sparking, I've checked the plugs out of the head arcing to the cam covers, as well as checked with a timing light on each lead.

[Lloyd]

Plugs fouled?

[nile]

Plugs fouled?

Plugs look fine when I pull them out, and they spark heaps, as well as the timing light showing that they are sparking while in the head.

[l1ttle_d3vil]

...So I checked that all 4 plugs were sparking and they weren't ...

...Plugs look fine when I pull them out, and they spark heaps...

My first thought were plugs are fouled... get some brand new ones and put them in.

[nile]

so I got the distributor cap, leads, and plugs from another working big port and put them on

Plugs went in clean and come out clean apart from a bit of fuel on them. I've been using contact cleaner and a rag to get the fuel off between attempts.

If they still spark outside of the head, as well as the timing light showing that they are consistently sparking. I just put them into my other motor and that still runs fine, could the plugs still be bad? They are only about 1,000kms old.

[Lloyd]

Are the plugs actually coming out wet or what? Fuel, Air, Compression, Timing, Spark. Got those then it should run. Which one is missing?

[l1ttle_d3vil]

I just put them into my other motor and that still runs fine, could the plugs still be bad? They are only about 1,000kms old.

The plugs can foul up in a matter of minutes depending on what they are, if you have access to an air gun blow the crap out of them to make sure all the cleaner is evaporated and chuck them back in dry, don't spray engine start on them or anything.

I use brake clean to clean mine - spray it on and let it sit for a bit, wipe them down with a rag, spray some more on and wipe it down again before blowing them out with the airgun. If I don't dry them out properly before putting them back in it still has trouble starting sometimes and won't idle properly for the first 10 - 15 seconds unless I give it a bit of gas.

[nile]

The plugs can foul up in a matter of minutes depending on what they are, if you have access to an air gun blow the crap out of them to make sure all the cleaner is evaporated and chuck them back in dry, don't spray engine start on them or anything.

I use brake clean to clean mine - spray it on and let it sit for a bit, wipe them down with a rag, spray some more on and wipe it down again before blowing them out with the airgun. If I don't dry them out properly before putting them back in it still has trouble starting sometimes and won't idle properly for the first 10 - 15 seconds unless I give it a bit of gas.

Okay cool I didn't think to blow it out with an air gun, I was just leaving them for a few minutes for the cleaner to evaporate. Will try that and see how it goes.

Are the plugs actually coming out wet or what? Fuel, Air, Compression, Timing, Spark. Got those then it should run. Which one is missing?

Yeah they are coming out damp with fuel. So it's getting fuel, there is no reason why it won't be getting air that I can think of but I'll try taking the plumbing off so air goes straight into the throttle body. The compressions came back really good.

Spark and timing are the most likely problems I think? But the timing light flashes which means it's sparking? Even with the plugs damp they still arc well, if I hold the plug 10mm above the cam cover it'll still arc to the cover. As for timing I'm 99% sure the distributor has toothed into the cam correctly, and have tried various angles as well as with the check engine jumper in and out.

[Lloyd]

Is it even firing or just cranking? Can you see if the spark timing is correct on the crank pulley when cranking with the timing light or not?

If its getting too much fuel (ie dodgy water temp sensor) then it could be flooding quite easily and not starting due to too much fuel also.

[nile]

Is it even firing or just cranking? Can you see if the spark timing is correct on the crank pulley when cranking with the timing light or not?

If its getting too much fuel (ie dodgy water temp sensor) then it could be flooding quite easily and not starting due to too much fuel also.

Apart from when it was actually running it doesn't really fire just turns over. My battery was getting flat and eventually died so wasn't turning over fast enough to use the light, but it's charged up and spinning faster now so will try the light again when i've got someone to help.

I did a side by side comparison of how strong the fuel smell was with the plugs out with my other engine and it was the same so I don't think it's running rich. Are there any ways to test if it's too rich?

[Lloyd]

You wont tell. Have you checked for fault codes? Sort out if spark is in the right place first. If it is then with clean plugs just put in then it should at least fire even if its overfueling

[matt dunn]

Does it even kick at all?


and are you sure the ign timing is correct while cranking?
I take it you have checked it with the timing light while cranking and it's about 10 deg?

[blindnz]

i had much the same after doing my head gasket on 4ag had the timing out 180. Doh!

[nile]

Lloyd, yeah it comes back with no errors though.

It doesn't kick, will try the timing with the light again. I had been setting it to 0° when I put the distributor in, but i guess the rotation of the distributor when it's in can give the 10°?

blindnz, I thought the same thing but I figured if i had it running the timing mustn't be that far out?

[CAMB01]

What blindnz is actually trying to say is that you can have the cams 180 degrees out to the crank when your putting the distributor in.
takes 2 rotations to get the cams back to TDC or firing no. 1 cylinder.

[rollaholic]

there should be a dimple on the cam that you can see through the oil filler to tell you when its TDC on 1

[nile]

Oooh yeah, as in I might have set it to TDC on the exhaust stroke? Cool hopefully that's what the problem is!