4Y missing and no power

[BryneF]

Hi i have a 1990 4Y 2.2L luxi. I have just set the cam timing and the crank timing right but there seems to be a miss on luxi. I have checked all spark plungs and all are firing 100% and timing is 10 degrees btdc according to the full brospeed 3 specification. I have an electronic ignition system. But some of the vacuum pipes have been blanket off and idno if that could be cauzing the problem. The bakkie still has very low power and a miss. Can anyone please give me some advise to fix this problem

[Mud Dog]

Hi and welcome Bryne!

Was it missing before you adjusted the valve timing? If you're one tooth out on the cam sprocket it will still run but give you the symptoms you've described, i.e. low power and missing with a 'lumpy' idle.

That's where I would start my trouble shooting checks. I've done it before myself where I thought I was on the mark after replacing a timing chain, only to find I was in fact a tooth out.

Hope that's all it is.

[Mud Dog]

P.S. An ignition timing of 10° BTDC does not sound excessive with a modified cam ( IIRC the standard setting for the 4Y was 8 or 9° BTDC).

A cut cam with a longer duration will almost always result in a lumpy idle depending on how wild or mild the cam is, but then it should smooth out as soon as it comes off the idle and power would typically be affected negatively at low revs but stronger at higher revs.

[JAMES399]

I have had a similar problem on both my '98 tacoma and my '03 hilux. The truck would idle ok, but miss under acceleration and be low on power. I checked the plugs and wiring. Both looked ok. A closer inspection showed carbon tracking lines on one of the plugs. I replaced the plugs and the miss was gone but returned a few weeks later. Replaced the plug wires and the problem is gone and has not returned after almost 250 kms. Evidentally, the carbon tracking was shorting out the one plug, but only under heavy load. I have had several problems where I thought the worst, but the solution was really easy.

- JAMES

[BryneF]

Yes the missing was there before i done the timing but luxi is still not running 100%. I have slightly more power but still not like the 2.2 should run. I have also noticed that my plugs are all burning white. Im thinking it has something to do with my carb. Does anyone know of a place it PE where i could send in my carb.

[Mud Dog]

Plugs burning white indicates an AFR that's too lean. Get it sorted because you're running the risk of burning valves.

The cause could be that it's sucking air through one or more of the vacuum pipes that have been "blanked off', sucking air somewhere else or with the carb itself (air screw / float level / jetting).

Hope you get it sorted soon.