HELP!!! Issues after new engine! (Not Resolved Yet)
 

Okay well its not me with the issue, my friend's 8 motor blew so she had to get a new one. The motor is finally in but its having a lot of stalling issues at the moment and any diagnostic tools are unable to connect/communicate with the car. It's a 2004 GT with everything but the nav system and roughly 84k miles. what could be the problem/where should we look? :dunno:

EDIT: Update to the issue, this is where it stands on 6/8/2011, everything else we solved.

Did you reset the e-shaft profile?
Commonly overlooked after a motor swap.
1) Turn the key to 'ON' (do not start).
2) Pump the brake pedal rapidly until you see the oil pressure gauge sweep to the middle and back down.
3) Turn the key to 'OFF'
4) Start the car.

If the dealer installed it, bring it back to them. Even if she has past 100k miles there should be something like a 12month/12kmile warranty on the engine they just put in.

If there is no warranty, start simple, check fuses and grounds make sure they are all ok.

i had her do this. these issues are still occuring with the stalling. plus what about the inability to communicate with the vehicle?
the dealer did not install, another shop did. ill let her know to check that if she cant get the car in my area so i can get my hands dirty.
could the possibility of a vaccum leak be the cause of rough idle/stalling? this would be so much easier if the obd-II port was working :icon_no2::rant: lol

Verify the ignition wires's coil-to-plug order is correct:
Attachment 172305

thanks for the help guys. i'll look into this stuff asap. and thx for putting up the post ricky. :)

Bump.
Anyone else have any ideas why nothing can communicate with the car?

3 fuses can upset the ECU - the 'room' fuse in the footwell, and the two 10 amp'ers underhood, marked 'engine'.

Try a hard reset, disconnect battery for ten minutes.

Check the vacuum nipple just behind and below the throttle body - if it's got it's hose connected, disconnect and cap it to check that the VFAD system isn't the cause of your stalls.

^+1
The ROOM fuse supplies the constant voltage to the OBD-II port and other devices such as the PCM.
So verifying all of fuses and air/vac connections would be a good start.

Capping off that vacuum line for the vfad leaves it always open, correct? If so I might do that either way. Any other vacuum lines I should check? And how do I check them?

Yes, you can cap the VFAP nipple and the valve will stay open.
I would then remove the hose between the nipple and vacuum chamber so you don't have a loose line dangling.

Where the VFAD nipple is under the UIM, run your hand around the intake curve and you'll find another nipple (and hopefully another vac line attached) for another vacuum chamber.

Then behind the oil filler neck you'll see a line with a blue disconnect attached under the UIM, make sure that line is secured and then follow it to the other side (close to the brake booster) and ensure that is also connected (that end also has a blue disconnect).

This is the thing that sucks about someone else doing a motor swap... its had to tell what they did or didn't do.
Hell... they could have the fuel injectors connected wrong... so many possibilities.

Man, just soooooooooooooo many fricken things it could be!
Which I wasn't 5 hours North, I could maybe help out some.
Anyway...................gotta get that OBD port working so at least you will have somewhere to start.

So is the only real issue(besides the OBD port), the fact that it just idles rough and stalls?
Has anybody gone back and verified that the air intake track is as it should be?
That both screens are in place, that the MAF was put in correctly?
Do you know if new coils, plugs, and wires were put in with the new engine?

From my understanding new coils plugs and wires were not. Though I could be wrong I'll check with Diandra later on that. I'm far from mechanically impaired (studying to be a mechanical engineer) so tell me what to check and where it's at incase I do not know

Might as well download the service manual... you're gonna need it:
https://www.rx8club.com/showthread.p...service+manual

thanks for that link. as soon as i can get my hands dirty ill use all the help from you guys to trouble shoot. if anything comes up, or if i check and note what i did check but the problem persists, ill post it here. thanks for everything so far everyone

Thanks guys. Seems like we might have gotten it figured out. Not positive yet. I'm gonna wait till tomorrow when the car is cold to take it out for another drive and see if problems persist. But thanks for all your help. And especially you for coming over Ricky. I don't know what I would do without you guys and this forum. :)

Not even a hint?

Not sure yet and I don't want to be the girl that sounds stupid so I'll wait till tomorrow and let the suspense get to you. :)

I hate being teased...

bro i didnt have the tools i needed to look further into the car (left them at home by mistake) and its real frustrating cause im here losing sleep cause i wanna work on that damn car!! -_____-

if the car is running at all and you cant communicate with the computer through the ob2 port---check uour tool--you may need a different one.

What tool? And today I'm hoping to check out the ecu and coil to spark plug and stuff.

hey everyone, some good news and then possible bad news, not sure.

Managed to get the OBD-II port working, and were able to pull the engine codes to see whats wrong. The issue is the Neutral Switch. ill ask Diandra for the actual codes again but we were able to narrow it down to that switch as the culprit of the stalling, rough idle, and CEL. Stupid radiator light is on too but thats just the problematic sensor in the reserve tank up top. Ill keep everyone posted so you guys might be able to help us finish the problem

why did you not take is to the shop you got it installed?

its kinda hard for her to make time to do that. she goes to school and works full time. the shop is about 90 minutes away, and she would be stalling out the whole way there. every stop, sometimes when decelerating, etc.

I already talked to the guy at the shop where I got it installed. He said it's a simple fix if that's what the problem is. And what Ricky said was right. it's over an hour away and a hassle to drive. Plus if it's as quick a fix as it seems then there's really no point to take it just to waste gas for 2 hours on a 5 minute fix.

The code is P0850. There are 4 connectors coming from the tranny. Two black and two white. They're connected black to black and white to white but there's two of each so i don't know how to tell if the black is plugged into the correct black and vice versa with the white. I'm still doing some research on it but if anyone has any info on how to tell which four males go into which four females that would be great. (no jokes or pun intended. promise)

This switch is what's supposed to be making my idle go crazy like it has been for the past few days.

And sorry for the tease boys. I wanted to keep it going for a day longer but Ricky messed that one up by posting before me. -___-

Thanks for the help so far guys!

damn Didi, if i was your boyfriend i might hang myself with how much teasing you do! ;P lmao Emil must be REALLY patient xD lol jk

These connectors take quite a bit of effort to connect improperly. The blacks go together and the whites go together and there are only two of each.

so youre saying the neutral switch would have to have gone bad?

What? How do you make THAT leap......?

I am saying that there are only two white connectors and two black connectors for the reverse and neutral switches on the transmission. I am also saying that someone who works on cars for a presumed living has to be pretty stupid to mix those up and connect them improperly.

If the harness is correctly connected, then we can presume one has a bad neutral switch. Until then, one cannot make such presumptions.

except that there aren't only two of each. it's 4 of them. let me break it down:

black 1 with black 2
black 3 with black 4
white 1 with white 2
white 3 with white 4

what's to say that white 1 doesn't go with white 4 instead of white 2? get me now?

ISO, that's what. Then, if things are still not clear, the FSM.

what didi is trying to say, there are four pairs total, two white and two black, for eight plugs total, four male four female.

IF the sensor is still good, there are 3 other pairing possibilities that may make it work (unless which ____ color male plug can be connected to either ____ color female plug in the event that doesnt matter)
I need a lift so i can figure this out -___-

You're fine as long as you don't mix the colors.
Just connect the males to the females of similar color... don't make these simple circuits complicated.

You can verify/test the sensors easily if you want:
https://www.rx8club.com/series-i-do-yourself-forum-73/diy-test-neutral-reverse-switch-200453/

Hey I could check that. Damn thanks for that helpful link. So if I don't get a reading in neutral or I get a reading while in gear, the switch is bad and gotta get a new one. Sweet thanks for that help.

I'll check on that stuff once I figure out what happened with my clutch now.. Ugh. I swear I'm spending more money on repairs than I am on gas to drive the car.. That's sad.. I had to be a rotary-loving puertorican didn't I.....

You might have popped a line with that race clutch. Damn thing grabs tighter than a virgin xD
Find the issue so we can finish getting your car broken in and we can worry about getting me into/getting a stick shift or your ridiculously yellow headlights :P

Jeez, I've been gone a few days and still not fixed?
Not given you both a hard time, just saying............and I know it can be frustrating.
Look like you got a lot of good info in the past few days and have made headway, so that's good.

Now, go test that neutral switch!!! :)

if didi was still living down the road from me i wouldve had her car up and going, but sadly shes living a little further away now and she has a pretty hectic schedule. (i dont blame her) but we're working on it little by little.

WTF?

There are TWO white female and TWO white male.
There are TWO black female and TWO black male.

Hook the whites together. Hook the blacks together. Just think Birmingham in the 1950's. You'll be fine.

That said, a bad neutral switch will make the idle crazy, but it shouldn't make the car hard to start.

hahaha!!! and yes thats what i mean.

so its connected that way, so simply put the switch is bad. damn Didi is pissed, her radiator blew and engine blew at the same time which made for a costly repair bill. replaced her clutch with a performance clutch while she was at it. gets the car started runs shit cuz of this switch and other stuff. got the communication problem fixed and find its the neutral switch. before it can be solved, her clutch goes on her. not sure what part but now thats shot = more money. shes pissed right now lol

Sounds like she is hooked by a pretty shitty mechanic.

Who knows :dunno:

Meanwhile, I'm trying to find a way to get my autotragedy under the knife and come out manual. Issue is I have no job and no DD so I can't put her under the knife just yet. When I do I plan to sell all the auto parts I don't need to go towards the cost of the manual ones.

ooooook.. It's been a couple weeks but here's whats going on. Finally got the clutch fixed. It was losing pressure because the clutch line had split right down the center. Got it replaced with a Russel Stainless Steel Braided clutch line, bled the system, and got my pressure back. Clutch working great. Took a look under the car at those damned switches as well. What happened was that one of the white ones seems to have gotten caught somewhere under the car and also split. So my boyfriend fixed that and no more check engine light.

So everything is almost good......

Except that the car is still idling low and stalling on me everytime I decelerate or stop the car. Well it's trying to. I can keep the car running by slowing down without the break and making sure i keep tapping the gas periodically. But if I leave the car in neutral with no pedals or decelerate without keeping the revs up over 2000rpm it just stalls out. What else can it be? Can those connectors maybe still be bad and have to replaced? Does the idle have to be moved up? If so how do I go about doing that? :scratchhe HEEEEELLLLLPPPP!!! :(

I'll give you a hint:

Go to the very first response on the first page of this thread, and follow the instructions. In fact, you might want to start at the beginning of the thread, and go through the first several suggestions and start over.

BC.

Nice hint genius. Except that I don't need sarcasm. I need help. Even though I'm a girl I believe I'm still smart enough to have tried everything on the thread and, well, being that I still have the same problem was open to more suggestions. Because after all that's what this forum is about. Helping people and getting info from someone who might know something more than me.

So if anybody else has any information that maybe wasn't covered in this thread previously please let me know. I'm taking the car to Mazda tomorrow anyway so I can have a tech drive it and see why I'm so frustrated. Once I get my news I'll post it up.

And again thanks for those of you who have been helpful. Means a lot to me.

Hey dick mouth, how about you shut your trap and take your heckling to another thread, she is having trouble with her car and merely asking for help, she isnt asking for word vomit from the town crier, last i checked this is PUBLIC FORUM, where questions are asked and answers presumably found, so lose the smart ass ego and if you dont have something productive to add to the thread, then do not anything at all you pedantic piece of _____________< fill in the blank with insulting word of choice......

- Emil (MiaS13) Diandras Boyfriend :git::git::git:

Comin in late and without all the info but have you checked the intake by chance? Gummed up MAF or intake screen from the boiled coolant would cause a crap idle.

My replacement engine had an erratic idle (surged, fell, surged, fell, stalled).

The dealer replaced my SSV (probably unrelated) and did some sort of Mazda service which cleaned not only the injectors, but also the throttle body, air intake system and intake valves.

It idles perfectly now ;)