P1300 Code, Replaced Spark Plugs Now Won't Start

Hi, new here and need some help.

I recently bought a 2000 TRD for my son knowing it had recently had a P1300 code (Igniter Circuit Malfunction), where the PO had changed the coil pack and said he had no further issues. We paid $3,500 for it, making it more than worth it to do some baseline maintenance. Custom front and rear bumpers, sliders, factory e-locker, BFG ko2 @ 90%, 286K.



Anyway, CEL comes back a week or so later, and it stalls a couple of times while at speed over the next week. Change all three coil packs with factory Denso, new NGK wires, all good for a bit and then CEL is back with another stall at speed.

Install new NGK spark plugs, noting the old ones had some oil contamination, particularly cylinder 1. Starts very rough, then won't start at all. We do the entire valve gasket procedure as there was obvious leaking, and clean oil out of the spark plug tubes (presume leaking plug gaskets as they were most likely original). 4 of the new NGKs are oil fouled, so install an entire new set expecting everything to be good now, and no change. It seems to fire and then dies, but only once unless you take the Key back to off and start over. It will just crank without firing at all after it dies.

https://vimeo.com/234583203

Engine flooding due to the new plug fouling seemed likely, but the plugs aren't covered in fuel pulling one back out to inspect and the usual tricks to overcome flooding aren't bearing any fruit. So outside of the valve gasket job and cleaning up the spark plug tubes, the only change was the new plugs and it had the NGKs in there before, although was time to change them.

Changed the battery and have checked the EFI fuses. Appreciate any thoughts as to what this might be as it seems a big coincidence that something else failed given the P1300 code makes total sense with oil in the spark plug tubes prior to the valve gasket job. Yes, plug gaps are good.

Thanks!

 

I am having what looks like the same problem judging by your video. After changing the ignitor coil and all the spark plugs, I saw no change. I finally took it into the shop because I am sick of throwing parts at it. Should know whats wrong by Friday. I'll let you know what I find out.

 

Thanks, really appreciate it.

 

Just what code are you pulling PO300 or PO1300 quite a difference

 

Yes, P1300 is not cylinder 1 misfire. It's Igniter Circuit Malfunction. P0300 is random misfire.

P0300 could be caused by a lot of things like a bad fuel pump, bad MAF sensor, or stuck EGR valve. It might be best to go through the flow chart in the repair manual for the code. It explains how to test these.

 

It's P1300, not sure why I said misfire as I've done some research and know it's igniter circuit.

I'll edit the first post. I'm going to focus on the ignition control module (igniter) next after some additional research.

I think what threw me off is the change in operation from doing the plugs, but seems the igniter is in a position to be "affected" when one is pulling the intake tube and that's part of the plug replacement...

 

When I put the JDM motor in my DC and it was in a position to actually hear it run, no alternator, no PS, no nothing on the front, I just wanted to see if it would start and run and it it made any noises. It fired right up and the check engine light came on immediatly with about 15 codes... one of them was the the P1300... how could that be?, its running. When I pluged the alternator harness in the P1300 code went away... is this going to help you, I dont know, I just find it kind of similar.

 

So I think my issue is obvious, and it was pulling the intake tube finished off this already loose igniter wire, turning an intermittent problem into what I have now.

 

eek... how are you going to fix that?

 

I accidently squashed a connector on my truck when i dropped my intake on it doing valve covers.
If you're a patient man you can take the connector apart, 1 wire in your case. That waterproof rubber piece slides back, you gently unbend the metal clip with some fine picks and maybe a rally small screwdriver, skin the wire back and reassemble, being careful to not warp the clip into something that won't go back into the hard shell connector.

I thought it was hopeless and was just going to cut the whole thing off and butt connect and shrink wrap another from someone willing to cut up a harness from salvage.
'Til I couldn't get anyone to part with one.

Edit: The metal clip comes out the front of the connector, make sure you slide the wire though and do all your work on that side or else you won't be able to reinstall into clamshell. (the clip part)

 

^^^^thanks. I still had some wire available as it broke off below its rubber fitting, so I melted solder down in the connector, then stuck the solder gun point in to melt the pool and quickly stuffed the wire back in. We have ignition and the connection holds as I tried to pull it back out (gently).



One final P1300 to clear...



I will still pick up a harness end and igniter (might as well have a spare) from salvage as I can wire in a bit of slack that way and I'm not sure I trust this fix for the long run.

Thanks for the inputs - hopefully this thread will help others. It could hardly have been more obvious, but my first time digging through one of these systems and obvious often arrives late.

 

And just to add some info... The computer sends a signal through the igniter to tell the coils when to spark. The coils send a confirmation signal back to the computer through the igniter. Without this confirmation signal the computer won't pulse the fuel injectors. So it's possible you can test good for spark but won't get fuel even though the problem was in the ignition system (igniter).

 

I have wire ends with pigtails available. PM if interested. I might even have the whole plug with pigtails.

 

Appreciate the offer . Scored this off a '99 4Runner yesterday. Whole thing was $5. Usually just the igniter is left when people pull the engines, but for some reason this part of the harness was cut and left.



Not super stoked to reverse a fully functioning repair, so may let it ride for a bit since the connection is hand test solid.

 

That's good info and what I finally realized must be the issue. If you look at the vid in my first post, the ECU gives it one go, shuts it down, and then it will just crank with zero firing. Key all the way to off and it gets one more go, and so on. Pretty obvious in retrospect that the ECU was shutting down fuel delivery based on lack of ignition signal.

Would be good to change my thread title for future reference since these ignition threads often trail off without much followup feedback. I found 2 or 3 snippets that finally put it together for me after searching probably 20 different ways (not just here).

The very first thing anybody should look at for a P1300 is the igniter plug wires - it's nothing more than an unobstructed visual to rule in or out.

 

Yes. Seems like any problem thread Ive ever started and had solved would benefit from a better search term in title for posterity than "Help, my so and so ain't workin' when I do this!" and it's hard to name a thread for a direction to a solution at the first onset.

They should allow an OP to change it.

EDIT: Op I'm not belittling your title, it's fine and it's where you started. Just that a code can go all over the place.

PS: That particular wire does look ripe for stretching to breakage in hindsight dunnitt?

 

Yea, that wire looks prone to stretching for sure. Not sure why the ICM mount was designed for it to be tight. And I agree on my thread title.

I did end up splicing in the new harness. My fix lasted about two weeks and pulled out again. All is well and I have a spare ICM that works for both the Tacoma and our ‘99 4Runner. Not bad for $5.

 

Super great info in here. Just wished it applied to a P1300 code on my 2.7

 

in my experience most of these type issues are traced ultimatly to bad grounds/wires/wiring. You are going to need a good multimeter and maybe do some reading on the internet regarding voltage drops. I am not talking checking resistance across a wire but the actual voltage drop. Most of the sensors and the ECM are running in the mili-amp range so any voltage drop is not good. I did a quick look through one Toyota manual and I did not see what Toyota says that the maximum voltage drops can be. In that case I would use the following as maximums.

• 0.00 V across a connection

• 0.20 V across a wire or cable

• 0.30 V across a switch

• 0.10 V at a ground

these are DC volts.

My 03 4 cyl Tacoma initialy threw the P1300 code after I put the motor in her and I traced it back to the ignitor bracket to inner fender well mount. The connector on the ignitor was giving me difficultites when I tried to pull the harness off and I didnt want to break the retainer clip so I unbolted the ignitor and when the motor went back in I put the ignitor bolts in only finger tight... it started and ran but threw the P1300 immediatly.

Although not a Tacoma but along these lines... I had a Nissan Pathfinder that had differernt codes set at random times for random reasons and I couldn't get the smog monitors to clear. I was researching each of the codes on the internet and I came across an old old post where the guy was stating that he couldnt get the smog monitors to complete even after thousands of miles driven. What he didnt say initally was that he had tried to cross a river and didnt make it and had to be pulled back out. While the motor did not ingest water the engine compartment was wet up to the inner fender wells and his problems started 6 months after that. Sometimes it would crank and start, sometimes no crank, sometimes a sluggish crank even after replacing multiple starters. This clicked the light bulb on in my head and I started to test for bad grounds/voltage drops on my Pathfinder. Sure enough there was a huge voltage drop from the negative battery cable to the aluminum cyl head. Why Nissan chose to ground the battery at the aluminum head, I do not know. I made a block to battery ground and then checked the ECU grounds at the aluminum intake to battery and had a varying* large voltage drop there. *I checked the voltage drop while it was running. Tacomas ground the ECU in a similar manner, to the aluminum upper intake on the V6's and intake on the 4 cyl's. I wouldnt be surprised if this is a similar problem. On my Pathfinder I made additional grounds for the intake to the battery and motor to inner fender-well to battery. The smog monitors cleared within 5 minutes of driving and all of the random CEL's stopped poping. I did some follow up and got someone from my local Nissan dealer to point out to me that this is such a problem on Pathfinders in that era that Nissan has made an additional ground harness as a factory authorized "fix", for $120.

It might be worth a saturday afternoon and unbolt the ignitor and run a tap through the captured nut on the inner fender well. I forget, is the captured nut exposed to everything the tire throws up or is it behind the plastic inner fender liner? anyway, take the grounds off the battery to block and see what they look like same for the inner fender to battery and the firewall to motor ground.

 

I am currently throwing this code P1300 (#1) and P1310 (same igniter code, but #3) on my 3rz. I just rebuilt the motor and am trying to figure this all out. I do not have an igniter on my year of truck. I have two coil packs and have checked all these ground. I did not remove the harness from the computer behind the glove box and haven't removed it to look at it either. I am kind of stumped as to what could be my problem since I've once overed pretty much all of the connections running to this. I stored my coil packs in the bed with a topper that leaks a little and it rained a few times pretty hard....dont think they got wet though. I am pretty much at a loss as to what to check next. I am going to check spark tomorrow and keep looking at wires. Any suggestions? Someone said check if timing is still good? I have 150+ compression on all cylinders though.