So I was driving home a few weeks ago and the CEL came on. It felt like my car was running on 5 cylinders. I pulled the ECU reading and aw yes, the good old code 51. Heres are the things I did:
1) I did the balance test and found out it is cylinder #1
2) used the stethoscope and heard the injector clicking away
3) swapped coil packs and the problem still remained on cylinder #1 (with a known good one of course)
4) Changed the spark plug with a new one and nothing, same problem
The few things I didn't check are:
1) Ohm reading on the injector
2) corrosion on the injector and the harness
I can't get the stupid clip securing the connector on the injector off (and trying not to break it) for the life of me. Any how, when I do get the clip off and if it turns out to be a bad injector it looks like I will have to pull out the plenum. So my question to my good brethren.
1) While I have the plenum off what things should I do (maintenance, cleaning, etc)?
2) How hard is it to remove the injector without pulling out the whole fuel rail or should I just pull the rail to replace the one bad one?
3) How do I check of the coil pack is truly creating a spark?
4) What other things should I check for?
Code 51
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budget300zx
- Posts: 199
- Joined: Thu May 29, 2014 9:11 pm
- Car: 90 300zx NA
Re: Code 51
Id recommend using a pick set to get the metal clip off.
if your going to be doing a plenum pull id recommend
1. replace all the injectors
2. Convert to phase 2 injectors if you dont already have them
3. replace the egr, plenum, and valve cover gaskets(make sure you remove, clean, and re-silicone the vtc selinoids if you do valve covers)
4. replace the coolant and fuel lines under the plenum
5. replace all the 20 year old vacuum line while your there
if you have the plenum off and pull the fuel rail you will have the chance to replace the fuel rail seals as well, injectors are also easier to remove this way.
check the fsm for coil testing.
if your going to be doing a plenum pull id recommend
1. replace all the injectors
2. Convert to phase 2 injectors if you dont already have them
3. replace the egr, plenum, and valve cover gaskets(make sure you remove, clean, and re-silicone the vtc selinoids if you do valve covers)
4. replace the coolant and fuel lines under the plenum
5. replace all the 20 year old vacuum line while your there
if you have the plenum off and pull the fuel rail you will have the chance to replace the fuel rail seals as well, injectors are also easier to remove this way.
check the fsm for coil testing.
Re: Code 51
hold your horses buddy. why do you think it's your fuel system? run the car for a minute, take picture of your old spark plug 1. was it clean when you took it out? burnt? it's more likely to be the ignition transistor unit or a loose wire/connector.
I'd recommend checking the condition of the wiring harness before doing a plenum pull and doing it anyway. the wires that run over the top of the plenum to the injectors tend to burn. just break off the wrap and look at the color of the wires. if the white ones are brown, time to cut it back to the harness and replace the conectors. better to have spare connectors before touching them first. they tend to crumble.
I'd recommend checking the condition of the wiring harness before doing a plenum pull and doing it anyway. the wires that run over the top of the plenum to the injectors tend to burn. just break off the wrap and look at the color of the wires. if the white ones are brown, time to cut it back to the harness and replace the conectors. better to have spare connectors before touching them first. they tend to crumble.
Re: Code 51
I'll see what i can do, but more than likely be on the weekend. thanks for your input guys. i'll keep you posted.
Re: Code 51
So i managed to remove the metal clip with a metal pick, thank you btw, and i did a ohm test and it only shows a 1 on the meter. I'm going to test the other injectors to see what they produce. thanks everyone and i'll keep you posted.