Hi everybody!

I'm in a dire need of group analysis on what to do with my car. I have just gotten my updated remanned engine from Mazmart installed with some new plugs and coils. The car runs great, mayby a little shake when getting down to around 750-800 rpm when warm and idling. It pulls good and steady and starts warm, unlike before the engine swap.

Now, the problem is that I am getting a random misfire code from chamber one ("cylinder one") when accelerating to above about 3500 rpm. I haven't really even accelerated hard once yet, as I've only driven the new engine about 300 km. We are talking a moderate half pedal acceleration. It was like this right from the start, I noticed it 50 meters from the garage and now I've been trying to troubleshoot it.
My garage has checked everything related to ignition. Coils, plugs, wires are all good. The ESS and MAF have both been cleaned. Exhaust readings are good and intrestingly when holding it around 3500 rpm and getting the misfire code, it didn't even change the readings. Needless to say, the cat is good as well because the readings are good. It's like it doesn't even really happen. I don't get stutter or anything, just the blinking CEL and when you read it, it is "misfire in cylinder 1".

Help, I need an exorcist or something!
Any ideas are greatly appreciated.

SOLVED:
Resetting the ESS with the old brake pedal trick worked. If you fail at it first, try slower, but harder pushes. Worked for me.

 

Guys, I don't even know if I should drive my car or not...? What to do??

 

Take it back to the person who did the engine swap

 

I've done that three times now and they cannot find the problem. The local Mazda stealership is also confused with it, but they'd be willing to run around in my engine bay measuring every wire that it has. Needless to say, I'd have to win the lottery before that is a viable option.

Thanks for the response, though.

 

Check the ignition and ess sensor once again. Check the grounding points and inspect the coils and wires individually (i hope you changed them while replacing the engine). I also hope that the spark plugs are fresh.

 

All ignition elements (plugs, coils and wires) have been run on a tester, so they are sure to work. They are all brand new.´

I will check the grounding points! Thanks for the tip!

 

If they're all new then check that the connectors and spark plug wires are in the right order etc.

 

Yep, they are all checked several times. They are in their right place and well secured.

 

How did they check the cat? Did they just check to see if it threw a code or did they drop it and actually looked inside? Sometimes a clogged cat won't set off a code.

 

Just deduction. No codes, gets good readings in exhaust tests and the car pulls really good.
You think it still could be clogged?

 

I wouldn't rule it out until I actually got eyes on the insides.

 

- 104 000 km or 65.000 miles.
- I have driven the car around 200 miles after the swap. Never close to redline yet, though, as I am worried about this issue.
- None that I can detect visually underneath the car or by listening when driving the car. Is there a procedure for detecting exhaust leaks? That is a possibility since I have a stock exhaust and it might've suffered some hits, especially during winter.
- I don't know if the trottle body was cleaned. I'll call the workshop and ask them.
- My intake is stock, air filter is clean and all the hoses are where they should be.

Thanks for joining in, Charles.

I checked and cleaned all grounding points. This didn't help.

Okay, Vlad, thanks for the tip! I gotta get the garage to strip it out. I tried to remove it once myself, but it seemed like the nuts were going to lose their form before unscrewing. No amount of CRC helped. :/

 

I went out to investigate and recheck if the garage really had cleaned the MAF and BOY had they ever!
The MAF wires were clean as ever, but the brown temperature sensor bulb next to it was slightly bent and a piece of the plastic protecting it had broken off. The sensor wires still seemed intact and the bend wasn't big, mayby one millimeter difference from the end of the bulb. Do you think it might not work properly after receiving some punishment, even if the wire still seems to be in one piece?

 

When you drop it, shine a flashlight in one end and then look into the other and see if you see any light.

 

Reset the ESS sensor a few times with an ECU reset....

I have had one that didn't seem to take the reset properly...it missfired until I did the ESS reset a couple of times...and it has been fine since.

 

You know I tried that, but since the new engine, the brake pedal trick doesn't seem to work. The needle just won't sweep. I tried resetting by just disconnecting the battery for about 15 minutes. Will that accomplish the same? If not, do you know another way than the pedal dance?

 

Your doing it wrong.

 

This. I've had similar issues in the past, also, and this worked.

You have to hit the pedal pretty fast for it to sweep (at least in my car). I couldn't even tell you if its 20 presses or not. Just tap it till it sweeps, then cycle the ignition and fire it up again. Test drive, report back.

 

Key to "ON" and pump the brake pedal like it owes you money until the fake oil pressure gauge needle sweeps.
Is that about right?
I'm like a tap dancer on that thing and nothing happens.

 

You have to do it hard and fast... . No but really, my whole car shakes when I do it.

 

 

Damn, that's one disturbing photo! The kid on the left side certainly looks like the bearded dude "tapped that".

--

Vlad, thanks for the advice! I thought I might've done it too fast and gingerly and really went to town with the pedal. "WHY...WON'T...YOU...STOP...BLINKING...AT...ME...Y OU...LITTLE...!!"
Behold! It sweepeth! Did it twice to be sure and I'll go have a drive soon and report.

 

Vittu JESSS!

It works! It runs like a dream on any rev (at least up to 7k that I dared to test) and no blinking CEL anymore!

Thanks to all of you beautiful people with sexy cars!

Thanks to Mazmart for a great engine! It really is smooth as cream.

Funny how the garage I used wasn't able to solve this. You'd figure resetting ESS would go without saying. Even I tried to do it many times and ended up thinking battery reset would do the same as I didn't succeed. The garage is a big chain that is owned by and does work to one of the biggest car sales organizations in Finland. The guy who did all the work to my RX-8 was supposed to have experience on rotarys.

 

Glad you like your Mazmart engine

Often the easiest solution is the most overlooked one. We tend to take too many things for granted from the shops we may have to rely on... this is sad.

 

Yeah, I'm glad you pointed me in the right direction.

Very true. Also I have plenty of experience on garages doing sub-par jobs on one way or another, but by nature I am a trusting person. Frankly, it would seem my trust was partly misplaced this time as they molested the MAF, didn't do this reset and last night I even noticed my front strut tower bar is missing!
I called them and they found it hanging on a coat hook somewhere. Jeesh. They'll install it back tomorrow.

If I had a garage of my own, I don't think there would be a problem on my car that I wouldn't rather learn to fix on my own, than to take it to bunch of strangers for whome my car is just another job. And yes, that includes a rebuild.
Besides, I really enjoy tinkering.