I know I must have forgotten something or done something retarded, but I just got done changing my spark plugs and now the car will fire over but not stay running. 98 GS300. 130k. This started because the car threw a code recently, P0306, cylinder 6 misfire. I read on here that it could be just the plugs so I changed them today. After cutting up my hands and finally getting them in I start the car and it fires right up, tries to idle and then just dies. Could it be a vacuum issue? I've checked all my hoses and I don't see any off or lose or damaged. I also used single electrode platinum plugs, NGK BKR5EGP. I heard that single electrode would be fine, but is this my issue? There was also oil on plugs 1,3, and 5. Valve cover gaskets? Any and all help would be appreciated. I have a funeral to attend in the morning and need my car.

*****UPDATE*******

The car will run now, the alternator has been changed, the coil for #6 has been changed and the plugs are now iridium. However, the car is still throwing P0306-Cylinder 6 Misfire, and now P1128. Is this TCM lock? Intermittently the throttle will go out and you have to push it to the floor to get the car to move. APPS sensor? TPS sensor? Dirty throttle body? How do I know for sure if the sensors are bad? Any help would be greatly appreciated. What about adjusting the TPS?

Thanks in advance!

Matt

 

Coil pack?

 

Yea, but I would assume that if that was the issue then the car would start and run as before, just throw the code again.

 

I allways check my gaps even when there pre gaped. what did you have them gaped at?

 

Check the connectors going to the coil packs and double check to make sur there are seated in. You may have a broken connector.

Good luck

 

I did have a broken connector, however I noted the wire position and connected them without the clip. I had to do this on my Supra while waiting for a new clip and it worked fine. I didn't think that would be the issue, however I'll double check the others to make sure they are properly seated as the car and the clips are considerably old.

The gap, I didn't check. :facepalm:

 

It's not a matter of gap or anything, you probably just forgot to plug something in. Are you 100% sure you plugged everything back in when you put the throttle body back on?

Also, it's probably not a plug connection (though you should check them) as the car would run relatively fine even if one plug wasn't firing, it would just have a rough idle. If you bought the recommended plugs for the car they should also come pre-gapped so you dont have to worry about that.

Did you plug the Mass Air Flow sensor back in down by the airbox?

 

MAF's plugged in. All connectors are plugged in. The TPS sensor connector?(front of throttle body) isn't snapping in like it should, however there appears to be no damage to it and no wires out of place in the connector. I don't think that could be the issue, however I could be completely wrong.

 

A large vacuume leak will cause a car to stall. I went through this recently when rebuilding the motor on my '89 T-Bird Supercoupe. Would start right up and die. In my case it was due to misaligned intercooler tubes, and when I found the issue and corrected it, the car started and ran like new.

If the MAF module has to snap in and isn't, as you say, you could be seeing a leak there.

Not too familiar with that motor since I have a GS400, but do make sure your air inlet system is sealed well, and check that all hoses and vac lines are going to where they should.

Good luck!

 

That could be the issue. Take a light and look into the connector on both sides, make sure there is no dirt lodged in there. Also make sure that there are no bent pins etc....if it's a really loose fit you may try neding the pins yuorself just a little bit so they make better contact.

 

doesnt the hood say stricktly use dual electrode... not single double check that, and yes that would be the valve cover leaking.. u sure it u didnt swap them wires around and see if your coil was the issue as well.. i dink u can swap them around correct me if im wrong...

 

If your valve cover is leaking you probably just need to tighten the bolts a little, try that before replacing the gaskets. The valve covers tend to work there way loose over time, when you tighten them don't crank down on them however as they are cast and will break. Just make them snug, kind of like doing a sparkplug, just turn it to snug and then a little bit more, not to the point where it's not turning anymore.

 

You are not suppose to gap them.

 

Bump. No solutions yet. Has anyone used single electrode plugs before without problems?

 

Nope, I've read, always use the stock Denso Iridiums.