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bonylad
bonylad GRM+ Memberand HalfDork
9/11/21 3:14 p.m.

I will update with pics and video once my phone charges.

Car is a 99 NB Miata 1.8.  Car was always down on power since I got it 2 weeks ago. I only ever had  P0171 system too lean code. Over the last few days the following has happened.

1. Excessive crank time. I can crank the car and it cranks and cranks. If i cut the key off and try again it starts. Stumbles in a E36 M3ty idle then idles fine.  

2. Hasnt happened recently but last couple times driving home for lunch, the car would not start, Just cranks and cranks and eventually it would.  

3. Anything over IDK maybe 30 percent throttle it spits and sputters. Until such time you go back to below that point.

4. LOW on power.  I get its a Miata but damn, its bad.

I HAVE REPLACED THE FOLLOWING

New camshaft position sensor

New crankshaft position sensor (adjusted correctly as far as I can say)

New fuel filter

New mass air flow meter

PO installed new NGK wires and plugs

Prior owner stated the car had sat for some years. He replaced the fuel pump with a Denso in tank unit. I suspected foul gasoline but its been driven two hours to me, and I have inspected the fuel that came out with the fuel filter and saw no reason for alarm.

I did pull the valve cover and to my eye the exhaust sprocket was a tooth out. i did not do a timig belt servce, it was just done by PO. I beleive that as it looks fine. I will be doing a complete service once I get the truck back on the road.  I did pull enough off to move it back in time.  
 

 

The results of all this is a E36 M3ty driving car that makes me regret getting it. I believe in the car and my abilities, though I am not so proud to ask my betters for help.

I seek comfort and guidance from the GRM pooba's to direct me. Praise the OMNISSIAH (WH40K reference)!

I will update with pics and a video that accurately shows the driveability issue I am plagued with. The wife is angry with me over this and any help would be ideal.

You can hear the sputtering again this is about 30% throttle any more than that it just gets worse to my knowledge it does not miss firing or rather setting any codes for it

I SUSPECT A TPS ISSUE, EGR ISSUE, OR IGNITION ISSUE.

Please and thank you!

alfadriver
alfadriver MegaDork
9/11/21 3:28 p.m.

Personally, I would suspect the fuel pump.  Get an actual replacement.  It's a pretty easy job- I had to replace mine after it siezed up from lack of use and exposure to air. 

NOT A TA
NOT A TA UltraDork
9/11/21 3:32 p.m.

I'd also suspect fuel pump and would test.

bonylad
bonylad GRM+ Memberand HalfDork
9/11/21 5:29 p.m.

Alright. Sounds fair enough to me. 

06HHR (Forum Supporter)
06HHR (Forum Supporter) Dork
9/11/21 5:34 p.m.

Another vote for the fuel pump, especially if it's been sitting. Down here they will rust solid inside the tank due to humidity  and condensation.

APEowner
APEowner GRM+ Memberand SuperDork
9/11/21 5:41 p.m.

Cam timing looks fine.  If you picture either of them moved a full tooth you can see that it would be way out.  I'd check fuel pressure to start.

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
9/11/21 5:48 p.m.

Yup, check fuel pressure at the rail and take a look inside the tank at the pickup. If it's good, getting the fuel injectors cleaned would not be a bad idea. 

JoeTR6
JoeTR6 Dork
9/11/21 6:02 p.m.

I've had jelly form in the fuel tank and mostly block a fuel filter from alcohol in the gas.  This can happen when it sits up for a year or more.  If the fuel pump checks out, I'd check the filter and lines.

bonylad
bonylad GRM+ Memberand HalfDork
9/11/21 7:08 p.m.

I just ordered a fuel pump. Overkill in size but. Idk.  Figure why I'm there. Lolz. Guy said a shop did it. But the shop also replaced the fuel filter. Which wasn't sooooooo. 

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
9/11/21 7:39 p.m.

Overkill in size can mean it overwhelms your fuel pressure regulator and now you have a different problem.

It's easier to diagnose than to load the parts shotgun. What's your fuel pressure?

alfadriver
alfadriver MegaDork
9/11/21 8:18 p.m.

In reply to Keith Tanner :

Keith- just out of curiosity- where's a good place to get an OEM fuel pump?  I replaced mine with a cheap pump that was the same thing, but when I'm done, I'd like to drop the money on a proper pump.

Boost_Crazy
Boost_Crazy Dork
9/11/21 10:28 p.m.

It also sounds like it could be an intake or large vacuum leak. 

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
9/11/21 10:35 p.m.

In reply to alfadriver :

Mazda is still around, although I don't know who their supplier is :) Deatschwerks makes a good stock replacement in my experience.

bonylad
bonylad GRM+ Memberand HalfDork
9/12/21 6:11 a.m.

In reply to Keith Tanner :

So many people to reply to but you ask a good question as well and the answer is I do not know as you're aware there is no pressure test port for the car so I do not have an easy way of checking it. Also I have heard of people running 255 L per our fuel pumps with no issue on the stock fuel system something to do with the fact that it runs 60 psi at all times and even a 190 can start to lean out at high RPMs granted this is what the Internet says so take that for grain. 

bonylad
bonylad GRM+ Memberand HalfDork
9/12/21 6:12 a.m.

In reply to Boost_Crazy :


I tested it to the best of my ability and found nothing I've actually replace the intake with a shorter design on the passenger side but even before that I did check and found nothing

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
9/12/21 8:02 a.m.

In reply to bonylad :

You tee into the line to check fuel pressure. You can make a tee out of fuel line repair parts fron the parts store so it just clips in.

The NB is more tolerant of an oversized pump than the earlier cars.

bonylad
bonylad GRM+ Memberand HalfDork
9/12/21 2:14 p.m.

In reply to Keith Tanner :

I had read that. Apparently even the stock pump can't maintain pressure near redline. Here hoping!  I will be sure to inspect inside the tank while I'm in there. Thanks!

bonylad
bonylad GRM+ Memberand HalfDork
9/12/21 2:15 p.m.

General thanks to you all for the help! Can't thank you all like I'd like but regardless I AM THANKFUL for all the help!

AWSX1686 (Forum Supporter)
AWSX1686 (Forum Supporter) GRM+ Memberand UltraDork
9/13/21 9:12 a.m.

Another thing to check, possibly the plug boots. I had a really weird misfire that started randomly earlier in the year. It ended up needing a new boot under the one coil. It looked fine, and the spring inside looked fine, but as soon as I put a new one on it ran perfectly. 

Edit: That might only apply to NB2 cars with the different style coils. Looks like NB1 uses the same style as the NAs with all 4 using wires. 

z31maniac
z31maniac MegaDork
9/13/21 9:20 a.m.

I haven't seen it mentioned, but after the fuel pump, my first thought was the O2 sensor. But I know they aren't as advanced on older cars as now. 

bonylad
bonylad GRM+ Memberand HalfDork
9/14/21 11:59 a.m.

No codes other than the 171 system lean.....the car seemed to be running a smidge better today.

 

Then it died. 

 

Went to lunch and 20 minutes of trying to start her it wouldnt - coworker came and picked me up, though not before it started like before (read: crank and try again - fire off on second attempt). Its at the house. The wife kicked it.

Pump should be here Friday.  Truck wont fire off as I have no park signal so thats waiting on that and some parts.  So basically Im using the companies shuttle vehicle to get to and fro.  It starts and ir runs. Life is great!

/my life.  

Prayers and positive vibes my way the pump fixes it. I am gonna be sure to inspect inside the tank while its out!

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
9/14/21 12:08 p.m.

In reply to AWSX1686 (Forum Supporter) :

The NB2 coil system isn't really any different than the NB1 fundamentally. The only difference is that two of the coils have a built-in proboscis to snuggle up to a plug directly and a lead running to a different plug. It's still two coils running two cylinders each.

In reply to z31maniac :

A failed O2 sensor usually makes a car run rich and generally won't prevent a start, as they don't come online immediately.

Stampie
Stampie GRM+ Memberand MegaDork
9/14/21 12:09 p.m.

When it won't start have you tried smacking the rear deck?  Also I had a girl pump relay cause a couple of intermittent no starts before it finally went totally bad.

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
9/14/21 12:27 p.m.

Tell us more about your girl pump relay and how it is used :)

bonylad
bonylad GRM+ Memberand HalfDork
9/14/21 3:02 p.m.

In reply to Stampie :

I can get the wife out there and she can smack it when I make an attempt at starting. Will report back.

EDIT: It didnt work, now her wrist is broken. OTW to the hospital. Will report back.

EDIT EDIT: She is pissed and now I have to cook dinner as she is in a cast. Will not report back.

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