P0301 after rebuild please help
 

:sad:Hi guys. After spending two days rebuilding the rx8 engine due to low compression I now have a misfire on front rotor. It dose not start properly first time idles a bit rough but once it is going it is perfect. all I get is error P0301.

The only thing I had trouble with when rebuilding was what injector plug go's where. Is this what is causing the error and bad idle? and if so can I have help plugging them in the rite place?

Thanks

Changed crank sensor. Cat is glowing hot. Ne ideas ?

Did you reset the ESS ?....

This is why you need to label every connection when you pull a harness.

yes this can and will cause a terrible misfire, Are you sure you got the firing order for the plugs/coils in properly?

Yep did the ess and plugs/ coils are fine. So must be injectors I guess. I can see one set of plugs for the injectors has a label round them. What set is this for? The only set I mite have got mixed up is for the two primary sets. Going to swap the coils and leads round today and see if the code gos to the rear rotor just to make sure.

How do yo know the coils are fine? The engine harness (connection from the engine harness to the coil pack) and the plug wires (connection from the coilpack to the plugs) both have a firing order that needs to be followed they need to match eachother.

Its easier to screw up the coil pack order than the injector order. the injector connections are shorter and have less play. you would need to stretch a connection to make it fire a different injector.

Yep coils are all good. It seams like its flooding on one rotor and dry on the other. The first main injectors ( the red ones ) I have the plugs with the tape on the wires. Can some one look at there set? Thanks.

LOL...might want to re-think that :)...ask Charles ;) This has caused more than one difficult to diagnose poor running thread :)

If you have any questions about the wiring of either the injectors or coils...you need to back up a step...and start tracing the wires to make sure they are correct. This sucks...but there is no easy way

Coil plugs only fit one way and I have info on the net to check it with. I know there fine. I'm sure its the injectors. The only difference in the injector plugs is one loom has tape around the wire before the plugs. Can some one check there's and tell me how they are. Pleaseeeeee!

You likely have the P2 or Sec injector plug for the rear rotor plugged into the P1...I think that is the easiest ones to mix up :)

You need to check the wire colors...and the harness position to make sure they are in the correct place ( there are 2 plugs with the same color wires :) ) You will need a wiring diagram to do this...there is a pdf one around somewhere..if you can't find it easily I have it someplace. PM me and I will look for it if you can't find it

Thanks. I'll try and swap them round 2moz and see what happens. I have found that diagram before but it's a bit hard to see the colours when there in the car. Thanks for your help

DON'T SWAP WITHOUT FIGURING THINGS OUT

Odds are that you might still end up with them wrong :)

It is worth the 10 minutes it takes to write down the correct colours ;)

LOL well I labeled mine, but seriously after 125k the wires don't like to go in any other way then the way they came out.

I have a feeling his next post will be, "Help everything under my hood is on fire and I don't know how to put it out.

Even the wiring diagrams have the same colours for the same injectors. Front primary2 and rear secondary are the same. Dose the metering pump need to be timed?

Just plug the MOP in :)

You can tell from the wiring diagram ( the pictures of the loom) which one is which...

This step is critical....make sure you are sure that you have the correct plug in the correct place :)

Na didn't touch the OMP but thinking about it there is no way to time it up. I think it's just a pump and the timing is done electronically. All back together and running a bit better. Turns out one of my brand new could packs were dead! So apologies to shadycrew31. It seams to still have a hot start problem aft all that and the water sensor light is always on when it used to come on somtimes. I have not tried to bleed the system properly yet so mite it be that?

Same thing happened to me when I rebuilt mine, I think the sensor goes bad if it dries up for too long. It's built into the coolant tank and is a common problem. You can order a new tank or disconnect the sensor and check your coolant level at every fill up.

Yeah I have seen the other threads on this but would it make the engine run rough? Also my secondary air pump dose not work

No its a dummy sensor does not control anything the PCM does not use it as a reference point. If you still have a cat you should fix the air pump, if you do not have a cat you should remove it.

There are multiple threads for the issues you are currently experiencing. you might want to search and find solutions to them.

Thanks guys but how come I still have starting problems after a rebuild ?

Did you build it?

Yeah but I'm not some guy in his shed and iv done and rx7 before. When its going it's perfect. Ne ideas ?

I'm using the lights on the spark plugs to get an idea of what is going on. When its turning over to start the following spark plugs (the top ones) don't light up very bright when its trying to start. I have tried swapping to coils over but same thing happens . Is it normal for secondary plugs not to be used on start up?

Is there a way I can test the crank sensor? what reading should I get using a meeter?

using the H/T lights you can get. it seams the following plugs are not as bright as the main ones when trying to start. Is this normal?