Sportrak ELXi misfire

Forum: 

On my way down to London last weekend my Sporty suddenly started running a bit rough. It's not hugely noticable at speed on the motorway except for a slight lack of power. But it shows up more at slower speeds.

I've now investigated the ignition system and found that when I pull the plug leads off in turn, they each make the engine run even worse EXCEPT for the lead on number 3 cylinder.

So I swapped the plug in number 3 into number 1 and still the problem persisted on cylinder 3. So I guess it's not the plug then!

Next I tried the no. 3 lead on plug 4 and again that worked OK.

I've now put no. 3 lead back on no. 3 cylinder and there is a pretty good spark jumping to the block, but when inserted the cylinder still does not fire.

I'm non too familiar with electronic ignition systems, so I'm now stumped for clues.

The spark seems to be getting to number 3 plug, but it's not firing.

The only other thing I've noticed was that plug 3 was a bit oily when I took it out. The others seemed to be ok. Could this be someting as the car uses a lot of oil?

Hopefully someone out there can point me in the right direction.

Andy.

Misfiring Sportrak

I had exactly the same problem on my 91 ELXi Sportrak.

I did the same as you did, swapped all the plugs and leads, and even swapped the injectors, but that made no difference.

It turned out the head gasket was leaking into #3 cylinder.

I would do a compression test and see if it shows up a problem.

Is the engine burning oil, you might see some blue smoke from the exhaust.

Check the oil filler cap for a mayonaise like gunge.

Check the coolant bottle for bubbles when the engine is running.

That was kind of what I was afraid of!

That was kind of what I was afraid of!

There is a lot of oil disappearing somewhere. I've not seen any mayo on the dipstick. But when I've driven about 100 miles I don't see any oil there either!!!!

Looks like time for a compression test.

Thanks for the reply.

Andy.

Plugs or distributor.

Before you go dismantling the cylinder head you must take a close look at the high-tension electrical system.
1. If you have a good spark at the plug cap when shorted to earth, then suspect a dud spark plug. Plugs might look OK but the internal electrode colud be broken and breaking down under compression. Renew the plugs. The plug gap must be set to 1mm.
2. If the plug cap spark is suspect then remove the distributor cap. Pull off the rotor arm and clean the rotor arm - its important to use non abrasive cleaner : do not use abrasiove paper! Then look at the distributor's carbon contacts .... look inside the cap. You will see four carbon tips. Each must be 100% perfect/clean. If they are burned or each has any sign of damage, renew the distributor cap and rotor arm. Get new rotor and distributor cap from a diy motor shop and not from expensive daihatsu.
3. Before replacing any old distributor cap, take a very close inspection of its surface. If any hairline crack is seen the cap must be renewed.
4. If you car is burning loads of oil it might be loosing oil into the cylinders due to weak cylinder rings. Its then burned and comes out the exhaust as blue smoke.
If the oil is due to a failed head gasket then oil or exhaust fumes are likely to appear in the cooland reservior.

All the plugs and leads are

All the plugs and leads are OK as I tried swapping the dodgy looking plug and lead from number 3 cylinder onto another cylinder and they then worked ok, with previously OK plug and lead from number 1 cylinder not firing when screwed into cylinder 3. So I'm pretty certain it's not either plug leads or the plugs themselves. This has been proved by getting a good spark from the suspect lead to the cylinder block.

There don't seem to be any signs of anything untoward in the coolant. But I do suspect the head gasket as the problem began part way down the motorway, after a fast run for about 100 miles. I'm going to take the car to the local garage for a compression test next, just to try and confirm if my fears are correct.

Don't want to alarm you here

Don't want to alarm you here but I was suffering oil loss, nothing showed on a compression test so it was diagnosed as worn valve stem oil seals. Before I had chance to get the work done the engine let go on the way home and was very sick indeed.
It turned out to be two burned valves, hardened and crack stem oil seals and a cracked piston rings (possibly from the engine going ker-bang! at 70 mph)
Ended up with needind a head rebuild, cylinder deglazing and piston oil channels reaming out plus new valves, seals and rings.
All up with labour it came to nearly £1500 - yikes! Shok
Hope yours is not so serious or costly, good luck.

Stone.