coils

We have a 98 Tacoma we got a little while back with a JY replacement engine in it that I don't know the year of. It has the dual coils on it. It started to run a rough when started cold and would clear up within a minute or so like someone hit a switch. Upon some advice from a mech I changed the coolant sensor on the back of the head and I cleaned the TB and the MAF. That cleared up the cold start problem for a bit but now its developed a miss and I got a po302 #2 miss code. So far I have checked the MSD wires and Denso Iridium plugs install by PO. Next step was to check the coil and injector for #2. While checking on possibilities and parts cost I noticed that the some places lable the coils for cyls #1&4 and #2&3. Is there an actual differance between them and can I swap them to check the coil to see if the miss follows the coil? The coils on it are Toyota with connections labled 1&4 and 2&3. I also noticed that the plug wire that is connected to the coil with labled #2 slot (third connector from front to back)on it is connected to the third cyl from front to back and the wire for labled#3 (forth connector from front to back)on the coil is pluged into the second cyl from front to back. Are these backwards and does it matter because its been running with them connected this way since we bought it. If they are backwards and running this way does it mean my missfire is in #3 and not #2? I hope this makes sense and thanks for your help.

 

After fiddling with the truck and clearing the codes I took it for a test run. Still had a miss and CEL came on. Went to auto store to look at parts and ask questions. They put the scanner on it and code 301 #1 cyl miss showed up. With the miss moving from #2 to #1 and looking what NGK plug wires looked like compared to the odd set up of the 8.5mm MSD's on it I bought the NGK wires. Came home and installed new wires and went for test run. Same thing. Will try new fuel filter next. Two parts guys familier with Yotas said to ditch the Denso Iridium plugs and put in NGK platinums. Would this be good advice? They look to be in good condition. BTW its a 2.7.

 

A plugged fuel filter won't just make a single cylinder mis-fire. All cyls. would be affected. If not a plug, or wire, then change the dist. cap and rotor. The cap could have a tracking defect causing the misfire to specific cylinders. Likely still the origonal cap and rotor anyway.

 

LDurchy. Thanks for the reply. I'm going to change the filter cause I haven't gotten around to it since we bought it. Its a yota filter and could be the original so I'm changing anyway to see if by chance it makes a differance. It doesn't have a dist. so no cap or rotor to change. It has two coils with two ports on each coil that I'm assuming is controlled by a cam sensor or something and the ECM. There is one coil with two ports and white numbers labled 1 & 4 on it and one coil with numbers 2 & 3. They are both Yota brand coils. I've never noticed the numbers untill I just unbolted them to clean and check to see if there was a possible grounding issue. Its just odd that the miss according to the thrown codes went from #2 to #1 when all I did was unbolt the coils as mentioned and pull the plugs and wires to have a look see. It was at that time when I switched #2 & 3 plug wires to the corresponding numbers on that bank of coil. Not saying it wasn't possible but as a SOP habit I only pull one plug and wire at a time. So unless I had a serious brain fart I don't think I mixed numbers's 2 & 3 at any point in time. This is my daughter's truck. I'm old school and still have a couple of vehicles with points in them and my DD are a couple of diesels. I don't understand how if I didn't mix up 2 & 3 wires was it running with them mixed up. To clarify could someone with a 2.7 please confirm the plug wire connections for me. Starting from the front of the truck going to the rear. The first coil port on the first dual coil is labled #4 and is connected to the the forth cyl. The second port on the first dual coil is labled #1 and is connected to the 1st cyl. The third coil port or the first port on the second dual coil is labled #2 and I switched it to connect to the second cyl. The forth coil port or second port on the second dual coil is labled #3 and I connected it to the third cyl. Thanks for your help.

 

here is the manual for tacomas--Just in case you did not know we had one here--hope it helps

 

newertoy. Yes I believe I have looked there and it wasn't 100% clear to me. Thanks.

 

I wanted to follow up on my post. I have fixed the problem. I must also admit and apologize that I did have a brain fart just not where I had concern. Before my test run on Thuresday I think I switched #1 & #2 plugs. Number two plug came out very hard so after I cleaned the threads I think I switched it with number one plug to check the threads. During that test run I got a phone call that our daughter was a passenger in a auto accident on the highway. I'm not sure what I did now as some of that time frame is a blur. She is banged up but ok. On Friday I thought about it more with a clearer head so I changed the sparkplugs and the fuel filter. Took it for a test run yesterday and today and the miss is gone. For referance I also talked to a mech and he said that the coil fires the whole coil at a time. I forget what type of system he called it. So #1 & 4 or #2 & 3 plug wires could be mixed and still fire ok. So that answers my question on as to how the truck was running with #2 & 3 wires out of place. Thanks for your help.

 

Glad daughter is ok. Don't blame you for mind blanking out on car repairs after that call. Plugs definately a 'might as well' if you pull one, change the set. And yup, I do just 1 plug at a time to keep things straight. I think the salesman told me my '93 was the last of the distributer type engines. Rusting thanks to Iowa's salted winter roads, but mechanically reliable and doesn't burn oil. I use the Bosch Platinum tip plugs and have been very pleased with their reliability.