RychGurl

I have a 96 T100 that's running pretty rough and is throwing a P0302. I'm pretty green and I'm looking for a little expertise. So far, I've done the following:
new plugs - NGK
new wires
swapped coils to determine if I could relocate the misfire to a different cylinder
checked timing
None of the above resolved the issue. I don't have any smoke or sulphur odor and the roughness doesn't seem to be better or worse when the engine is hot or cold. When I start the pickup, it fires right up.
I haven't checked the compression in cylinder 2 and that's probably my next step. I'm thinking maybe a bad injector, but I have no idea how difficult it would be for me to change it out myself. I've not even looked that far.
Any suggestions for a newbie-girl from the experts?
Thanks!
PS. In the interest of full disclosure, it's also throwing a P0500 and the speed/odometer aren't working. I can't see that it's unhooked, but it's not working. ?

250000_yota

Easiest way I've found to check an injector is to hold a stethoscope or long screw driver up to the injector in question and see if you can hear it clicking. Someone correct me if I'm wrong, but #2 is the first cylinder on the passenger bank, so swapping it out if it is bad shouldn't be too hard. If that leaves you in the same place, try a compression check to see how that particular cylinder is doing.

And as far as the p0500, the speedometer cable is probably broken. Not too difficult to replace. Try searching on herer for a write up.

ekesz13

I just had a P0305. I cleared it by taking out the NGK Single ground plugs and replacing them with the proper Double grounded plugs. Cleared the light by disconnecting the battery cable and it has stayed off for over a week now. Previously it came back on within a few miles. I found this out by researching forums, like this comment:

Twin ground electrode type spark plugs are used on the 5VZ–FE engine. Due to the employment of the DIS system,the number of spark produced is double that produced in the conventional ignition system. To maintain spark plug durability, the ground electrodes have been made bipolar.

In the DIS system of 5VZ–FE engine, each spark plug is connected to the end of the secondary winding. High voltage generated in the secondary winding is applied directly to 2 spark plugs. In one of the spark plugs, the
spark passes from the center electrode to the ground electrode and in the other plug the discharge is in the opposite

direction, i.e., from the ground electrode to the center electrode...

I see too many "tune ups" that come in with poor performance and fuel economy mainly due to afermarket plugs...

Due the right thing...get some original plugs and make Your engine happy

wowzers

I have the same exact problem only in cylinder 3.

When I hook up the code reader I get P0303 CNF and PND MOD 10.

I have replaced the plug (with NKG dual electrode plug) and wire to cylinder three and swapped the coil to see if I could get the another cylinder to misfire. No luck. you can also smell gas in the exhaust so I don't think I'm getting a spark. Is there any way the other plug that the wire goes to could be causing this?

Any suggestions?

BamZipPow

If yer gonna pull the injector(s) fer replacement/cleaning, you might as well do the valve cover gaskets as well. Don't fergit to use RTV in the cam corners on top of the valve cover gaskets as well on top the cam plugs. It would probably be a good idea to replace rear cam covers with new ones as the ones you have in there are probably cracked and leaking. RTV on them might work (in my case they didn't) but it's not worth the gamble to try it and have to pull everything off to replace them in the end.

RychGurl

Thanks all for the suggestions. My next steps will be to check that injector and check compression in that cylinder. I had so hoped for a simple fix, but it's becoming more involved. Oh well......I'm learning in the process so it's not a total waste.....

wowzers

What do yo mean by cam covers? I have never had the valve cover off of this pickup before.

CJM

There are small plastic covers where the cams ride when you remove the valve covers. They go between the head and valve cover.

RychGurl

EUREKA!!!! Thanks to ekesz13. That was the ticket. Funny.....there's a big sticker in the engine compartment that says use twin ground electrode plugs. Uhhh......duh. When I bought the truck, it had standard single grounds in. When my mechanic replaced the plugs, he put singles in. When I went to a local auto parts store and bought plugs for that engine.....the dude looked it up and sold me single ground. After ekesz13's response here I called my local Napa and asked if they stocked them. The guy didn't even know what we were talking about. Ugh...... I'm just glad that was the ticket. I REALLY wasn't looking forward to tearing into it to check injectors.
Thanks a gazillion! Next, I've got to dig into the speedometer cable issue. Wish me luck!

ekesz13

I just PM'ed you about that sticker. The guy who owns the truck had never seen it before either, lol.

Similar story at our parts store, the guy tried to talk me into the single electrode NGK plugs. He had no idea what double electrodes were.

Glad to help, forums like this have helped me immensely in the past!

RychGurl

Ok, now I'm just flat cranky. So, I was totally stoked because on Saturday, after changing to the twin ground plugs, it ran like a champ. I drove it all over the place with NO trouble. No stumbles, no P0302. I figured I should start driving it a couple of days a week so that I could find any other little "secrets" it had so that I can have it ready for the back country this spring. I hit the highway yesterday morning and it ran like a giant steaming pile....... Engine was rough and it was stumbling badly. I have almost an hour commute and it was a rough ride. When I got to the office, I put the code reader back on it and guess what.....P0302!!!! WHAT?????? How can that be??? I drove it for almost 4 hours on Saturday with no issue. I so thought this was behind me. I'm still thinking maybe a bad injector, but it seems odd that it would have been consistent until Saturday after the plug change.....then run like a champ for 4 hours, then back to crap. Does that seem odd to anyone other than me?

8lugnuts

I have no answer why it ran good for several hours but you have at least eliminated *one* culprit, the plugs. If you have not already seen all of the reason codes for the P0300-PO302 code familiy then go to last post in this thread:
https://www.yotatech.com/forums/f2/p...isfire-277108/

I would start there and check off each one as you eliminate them.

Just curious, what brand of plug wires did your mechanic install?

RychGurl

The "mechanic" (me) installed whatever the dude at Car Quest sold me. I'd have to go look at the box, but I think they were actually Car Quest branded. I know they weren't Bosch.

wowzers

So I spent the better part of my day taking everything apart to change the injector. And since I had everything off I decided to do my valve cover gaskets too. Sure enough it was a bad injector causing my rough idle and code to be thrown. Got everything back together and now I'm throwing P0115 Engine Coolant Temperature Sensor. So Now I get to track that down. I saw in another thread on here that that code comes up when the tranny cooler craps out. Can anyone tell me where this sensor is located? Maybe I just left something unhooked or not hooked up all the way.

Thanks for the help on this. This forum made this project so much easier.

wowzers

I just ran the reader again and it also has a P0325 knock sensor and P0330 bank sensor that it is throwing. I must have definitely left something unplugged. Unless you guys have any other thoughts.

RychGurl

How long did it take you to change out the injector? I've not yet torn into that, but I need to.....

wowzers

Oh you could do just the injectors in a couple hours. I did my valve cover gaskets too so it added a little time. After having done it I had to put new o-rings on an injector because it was leaking and I had the whole thing stripped down in about ten minutes. The thing that helped me the most was numbering my vacuum lines and taking several pictures before I started for referencing.

This thread was a huge help too.

https://www.yotatech.com/forums/f2/f...es-how-109389/

RychGurl

Sooooooooooo...........after much agonizing and nickel & diming..... I finally caved and took the truck to the shop. Turns out it was a burnt valve. Not what I was hoping for, but at least I can address it. Now, after a valve job and a new water pump I got it back. No more P0302, but my troubles aren't over yet. Now it's cutting out badly and the tach will drop and jump a bit and occasionally dying and throwing P1300 which indicates that there's an issue with ignition coil 1 or the ECM. Now, when the shop put the thing back together after the valve job, they broke something. He said it was a clip on the fuel injector. He was a little vague about it. When I look at the connections between coil number 1 and the injector it does look like a piece is broken. When I surfed around checking it out, it appears that it's the housing connector. The part number on the part is 11153 E39. I'll try to attach a picture of the broken clip.
Could this be causing my cutting out and loss of RPM's? I love this truck, but it's rapidly becoming the bane of my existence.
Thanks!
MO

Duke Louis

This is a part that i need. What is the name of this part? A rat chewed through the wire.

Ram1

Misfire problem. I had the same issue with my truck ( 5vz-fe ) also. I had a misfire code on cylinder 5. When I was doing a maintenance tune-up, I discovered that the previous owner had installed autolight plugs, single ground element. I also had a weak coil pack on number 1 cylinder. Had factory wires and I replaced them with a larger wire size and the factory plugs. Swapped out the weak coil pack and solved the problem entirely. The truck ran like it had a new engine in it. On another note, the cam seals should always be replaced with the valve cover gasket. I didn't do mine the first time and had to tear it apart again for the repair I should have done to begin with. Another set of valve cover gaskets and intake manifold gaskets. Learning experience for me. Won't repeat that mistake again. LoL