Turbo Engine Died this AM; PLEASE HELP!
 

Hey Guys,

A few months ago I turbo'd my 92 miata with a car mechanic friend of mine. (Please bear in mind that the first time I picked up a wrench of any sort was about two years ago, so I am not a mechanical genius like most of you.) Before I turbo'd, I had a shop do an engine swap, change all the hoses, clutch, tranny, flywheel --basically refreshed the motor. I ran the can for a few months after that to make sure everything was fine with the engine and swap before I put the turbo and IC in. Car has been running fairly well since the install.

This morning, car started normally, but when I had almost reached my destination, the check engine light came on and I lost all power/ engine shut off; I popped it in neutral and coasted to a parking lot. I tried to start the car but it would not turn over. I let the engine cool down a bit and had someone try to start the car while I looked at the engine bay. Looks like the power is working as the alternator belt moves when the key is turned and the radio comes on/cool down fan turns on, but the engine wont start up. I checked the IC hose connections and everything looks tight.

Anyone have any suggestions what might be the problem and why the car wont start? Would this have something to do with a dead starter? Since the car was in motion when it died, I would assume that the starter had nothing to do with the problem. Any helpful suggestions would be appreciated as I am at a loss right now.

Thanks,

Ben

Since you have a CEL, reading the code would be the first step. Open the diagnostic connector (under the hood, near the left shock tower) and place a jumper wire between the terminals "TEN" and ground. Then get in the car and turn the key to the RUN position. The light will flash a code at you. For instance, flash pause flash flash (long pause, then repeat) means 12. Here's a basic primer on what the codes mean: http://www.miata.net/garage/faultcodes.html

It's possible that you have a broken timing belt. Open the oil cap on top of the engine and you can see the exhaust cam. Have a friend crank over the engine while you watch the cam turn (or not turn, as the case may be).

The timing belt was just replaced, and it looked like it was moving appropriately when the car was cranked... could it still be broken?

what do you mean by it wouldn't turn over? you hit the key and *nothing* ? or you hit the key and it spins and spins? if it spins, does it spin at a normal speed and sound normal?

The CEL will be telling. Read the code.

Is the car cranking?

The belt spins, but the engine doesn't start.

it seems to be spinning normally too

Start with the basics, are you getting fuel. Are you getting spark? Check the wiring at the AFM (assuming you have one).

Might help if you describe your setup for us.

What belt spins? The fan belt? Did you look in the cam cover (remove the oil cap and peer in) to see if the timing belt spins?

sorry which belt in the fan belt? is it the one by the alternator? I have not had a chance to remove the oil cap as I am at work. What a crappy day.

There is no fan belt :) There is an alternator belt and a possibly a belt for AC/PS ... depending on how your car is equipped.

I have a stripper model, no ac no power anything

I'd think it was the timing belt since it was just changed. Maybe it was installed incorrectly?

Stripper model? It comes with a pole? :)

Confirm that the timing belt is intact. Make sure your AFM is still plugged in. Do the easy shit first and get it out of the way.

Sorry AFM? (noob) Is this connected to the air box? Thanks for your patience.

Air fuel meter (AFM) Its exactly as you described.. metal piece on the intake side.

Click the link in my signature. At the very top of that page is a picture of an AFM. (It's an RX-7 part, but the Miata one is nearly identical).

Location varies in turbocharged cars, but it's going to be between the turbo and the filter. It has a big rectangular electrical connector on the side.

However, I'd think that even in the absence of an AFM signal the engine would fire while cranking... I'm leaning towards timing belt, CAS, maybe ignitor, somewhere in this neighborhood. (it could even be something amazingly simple like a blown fuse)

Grumble, do you know what modifications have been made to your car to control the fuel and ignition timing?

afm IS the airbox. It has a connector plugged into it.

You get spark without the afm plugged in, but you get no fuel.

Crank for a while and then pull the spark plugs. This should give you an indication of whether there is fuel or not, is the plug wet?

You can try jumping the FP/GND on the diagnostic connector to run the fuel pump.

I also have an RX7 air box. I have fuel injectors from a 1.8 which I have sent to witch hunter for refurbishment. I have a vortek air fuel pressure regulator. Basically a Greddy kit...

is it simple to pull a spark plug? I have never done it before.

Yup. As simple as "righty-tighty, lefty-loosey" :)

Pull the spark plug out, then use the correct spark plug socket and remove. This isn't a sure way to know if you are getting fuel, but if the plug is wet you know for sure you are.

Okay so action steps are:

1. Read code using paper clip to connect to 10 and ground

2. Open oil cap on engine to see if exhaust cam is spinning

3. Pull spark plug and see if it's wet

Thanks for your help and suggestions guys

Not 10, TEN. Short for Test ENable, I assume, but that's what the terminal is labeled.

I agree with the timing belt possible being the problem. If the cam DOES turn when the engine is cranked then it is likely a problem with the ignition or fuel system.

4. Check for spark
4.1 remove one spark plug wire
4.2 insert screw driver into the boot on the end of the wire so that it contact the electricals inside
4.3 ground the screw driver to the engine somewhere
4.4 have someone crank the engine, watch for spark between the screw driver and the grounding point
4.5 repeat on the other 3 cylinders

If you don't have spark first thing to check on a 1.6L engine is the ignitors. Someone else will have to help you with that as I have a 1.8L, no external ignitors.

5. Check for fuel
5.1 remove the rear fuel line where it attaches at the fender (this is the return line)
5.2 hold it near some kind of container and turn the key to the on position (not start)
5.3 you should get pretty good flow, probably about 1/3 of a gatorade bottle in 10 sec.
5.4 repeat with a set of vise grips clamped onto the hose enough to pinch it down, but not enough to close it off completely.
5.5 repeat bottle test

If you don't get very good flow you probably have a fubar fuel filter and/or pump

If you have no flow you have a dead fuel pump, or the switch in the AFM is broken so you arn't getting power to the pump.

6.0 If there is no fuel
6.1 take the rear carpet out
6.2 pull the inspection plate on the rear deck
6.3 unplug the fuel pump
6.4 insert two piece of wire into the chassis side of the connector and connect those to a multimeter
6.5 turn the key to the on position and see if you are getting 12V

If you get 12V at the pump then your pump is toast (provided you got no flow in the previous test)

If you do not get 12V then you have a blown fuse, or a bad AFM fuel pump switch.


Have fun! :)

ok another silly question, wouldn't I have heard the timing belt break if it did break at that point? I wasn't driving the car hard at the time...

Great trouble shooting advice here.

In contrast:
http://forum.miata.net/vb/showthread.php?t=241677

3 replies and already on page 8.

I had one go on a different car, didn't hear it at all. Had no idea what happened until I got home and took a look at the engine bay.

you guys are awesome; thanks for the help.

holy crap you turbocharged your miata yet have never removed a spark plug. Im poking fun at you while you're down, basically rubbing salt in your wounds. I should feel bad about that.

But seriously cars need spark, air, fuel and timing. It's gotta be one or more of the above. Start narrowing it down!

Since your car died while driving it makes me three things... Fuel, Spark and timing belt.

First thing like everyone is saying would be to check the code. Cause for all we know the code is telling us that something broke aka your AFM and now your not getting fuel.

Next thing would be to check the timing belt. Just like everyone said.

The last would be to pull the plug and see if they are wet, and also to check if you have spark. I have always check spark this way, by setting the spark plug back in the plug wire and setting it on my valve cover. Have someone else crank the car and check to see if it sparks. This was normally checked at night or in the shade. I am not sure if someone else has a different way to check. BTW I take no respondabiltiy blah blah lol


Good luck man

I have an alternate method for testing in direct sunlight, however it requires the use of a neighbor's cat. Not sure if the OP can obtain said device while at work.

shoving a spark plug into the wire and setting it against the lifting point hook thing is the best in sunlight.

which wire? and to test what? Unfortunately no cats at work, and since my boss is out of town (I don't particularly like him) I can't ask him to volunteer, and being blond I am sure he would consent if I told him it would increase his likelihood for promotion

Lol

any spark plug would work... I have always used the plug with longest wire, and easiest to get, so plug 1 will work.

I like the cat idea, we have a lot squirrels around here, may have to use them for testing:bigtu:

Grumble just chill out man as the rest of the guys are saying this is dead simple. You know something is wrong so use your brain and the info we have given you timming belt etc, to narrow it down. This is exactly what we all do i hope you get it all taken care of gl man.

I gotta agree with SloS13. Turbo'd the car but don't know how to remove a sparkplug? Is he/she yanking our chains?

If you are serious about those questions get it to a trusted local mechanic. If you really want to do it yourself get a manual like Chiltons and read up. If this is your daily driver I doubt you want to mess around learning how to diagnose your problem, get parts and fix your problem while you ride the bus to work. If it's a secondary car - great, take your time and learn something.

I've always believed there are no dumb questions but then Grumble asked "is it hard to remove a spark plug?"...

Grumble where are you located. if you're close (ie within 60 miles) i'll come and help you

Same here... I'm down with helping if you're in the houston area. I'd be accompanied by at least one other miata... possibly more.

OK so I'm an ass for busting on Grumble. I've seen people flamed for a whole lot less here though. Guess everyone's feeling helpful and perky. Must be taking the right meds.

Well, we've all been there. It's just a little different now that we have internet forums to go check in with.

I remember very clearly the first time I removed a spark plug. It was from the engine of my '71 VW Beetle. Granted, the engine itself was sitting on the ground at the moment... :cool:

Ok,

So I did the first bit of the diagnostic. Removed the oil cap on the engine and had a friend try to start the car. The exhaust cam rotates so I am guessing that the timing belt is working fine. I also pulled the code from the engine and two codes came up:

12: Throttle position sensor

15: Oxygen sensor (output too low)

I checked the O2 sensor and it seems to be wired correctly. Everything is connected to the air box as well.

I spoke with the guy who towed my car and he said there was a possibility that it might be the throttle position sensor needing to be replaced. Is this a possibility? Tomorrow I am going to test the spark plugs to see if they spark.

Thanks for the helpful advice. Not putting anyone on by my extra "noobness", but no one in my family is mechanical at all-- this is all new territory for me.

I'm in the S.F. Bay Area btw; thanks for the offers of help.

I once had a car that had a faulty TPS, it never stopped it from starting, however, it may be different on our cars as mine was adjustable and i dont believe the miata's is. O2 sensor can look good and be wired correct but can be faulty, it's always good to replace, not really the cheapest thing, but, the TPS is a lot more expensive new IIR

grumble the tps could well be the problem test it with a multi meter and see if the output is right i forget the values you need. Also have you verified that the Fuel pump is on this will cause to low a reading on the 02 as you would run out of fuel take back the carpet and listen on the outside to see if you can hear the fuel pump turn on if it turns on then this might not be your problem if it does not. Remove the acces panel and check the wires to the pump, if you get good ground and hot electricity then the problem is the pump. If not then it is the wire. Maybe try to contact medysn he is in the san fran area i believe and is familiar with all this stuff. GL man.

I turned the key to the on position and went outside the car. I listed carefully, and I heard what sounded like the fuel pump coming on; sounded like liquid pumped into the car. When I turned the far fully off, the sound stopped.

I predict fuses or loose electrical connection. 'nuff said. ;)

he has life!
 

So I played around with the TPS connector jiggled some wires, pulled the fuses to make sure they were intact and put them back in, and more throughly checked the connections and then tried to start the car. Low and behold I almost pissed in my paints as the engine came to life. The car is now currently heating up in the garage and is idling normally.

I have tein suspension which rides fairly rough, and part of me is wondering if the car being on is a freak think or if the bumpy suspension dislodged something. Either way, I will keep you all posted. Thanks so much to everyone that commented, for the suggestions, and help. This is a great forum.

So I let the car run to normal operating temp and everything seemed fine. I got into the car and reved the engine really hard I got a CEL and the car died. I was able to start the car back up after this and there was no cel/engine and car were running normally.

I turned the car off and was able to start it back up. Since the car was able to start and idle normally it seems that the fuel pump is working, that the spark plugs are working, ect.

Scratches head. I did some research on TPS's and suppoosedly the car should still be able to start without one. DOes anyone have any ideas what might be happening to make the car run normally and then shut off? Could this be some other electrical problem or actually be related to a faulty tps?

yet again, check those codes, they will tell why it did that. Could be your AFM. Maybe when you rev it up, the AFM doesnt get the signal or whatnot and doesnt allow the air to enter the engine, IE you lose the one of 3 variables needed(gas, spark, air) Keep me updated. If you pay for me, i'll fly haha out

See the code didn't last; maybe the cel just flashed when the engine died. In any case the code is gone now and the car is running normally. I checked the spark for each of the plugs and they are all sparking.

How do you check to determine if your afm is working properly? Is this another check with a multi meter/?

Car is starting and running normally now, for now anyway.

Fyi my timing belt slipped and saw similar issue - car wouldn't start, throwing CELs that were related to CAS and AFM and of course I checked (watching the cam to see if it was turning when the engine was turning over) which can be misleading since in my case it was turning over fine but the belt slipped by 10 deg retard.

got a question, can you just slowly rev the engine???

I am wondering if your TPS is gone and when you apply gas the ecu flips out and dies. Also if you are able to slowly rev, I am wondering if a wire, maybe ground is lose.

You maybe get a bad connect somewhere... most likely TPS or O2 since both had codes. Messing with wires maybe you reconnected then and when you reved it you broke the connect.

im pretty sure there's a multimeter test for both TPS and AFM. Check the TPS and the AFM with the multimeter(i'll look for the variables) and it should determine your prob.

Okay here's what i found. To test the AFM, remove it from the car.


second:

The ports on the AFM plugin (on the AFM) from Right to Left are :

Fc - E1 - E2 - Vc - E2 - Vs - Tha A



using those ports measure using a multimeter. Here are the resistance levels.

Fully Closed: (E2 and Vs) 200 - 600
Fully Closed: (E2 and Vc) 200 - 400
Fully Closed: (E2 and Tha A) -4Degree F 13,600 - 18400
68F 2,210 - 2,690
140F 493 - 667
Fully Closed: (E1 and Fc) Infinite

Now for the Fully open:



Fully open: (E2 and Vs) 20-1,000
Fully open: (E2 and Vc) 200-400
Fully open: (E2 and Tha A) -4Degree F 13,600 - 18400
68F 2,210 - 2,690
140F 493 - 667
Fully open: (E1 and Fc) ZERO

Best of luck, i'll find the TPS and post up again.

TPS time... First: Disconnect TPS connection
2. Connect SSTs or an Ohm meter to the sensor
3. insert a feeler gauge between TPS stop screw and stop lever
4. note the operation f the buzzer or the continuity between terminals.


Feeler size .4mm (.016in) Buzzer: yes Continuity: (between IDL and TL yes) (between POW and TL no)


.7mm (.027in) Buzzer: no Continuity: between IDL and TL - NO
between POW and TL - NO
Wide Open Throttle: Buzzer: yes Continuity: Between IDL and TL - NO
Between POW and TL - YES

Oxygen Sensor testing:
1. Warm engine up
2. Disconnect sensor connector
3. connect voltmeter between O2 sensor and ground
4. Run engine @ 3000 RPM until voltmeter shows approx .55V
5. Increase/decrease engine speed suddenly several times: Verify when speed is increased it reads .5-1.0V and when decreased it reads o-.4V

If it doesn't read this, REPLACE.

BEST OF LUCK
I'm tired of reading this damn manual now.. haha now fly me out to the Bay Area and have me work so i dont have to go to work :)

Dude, what are you using for engine management.
Better yet, post IN DETAIL your entire setup. I don't suppose you have an Emanage, Bipes, or anything that requires splicing into any wires anywhere perhcance?

I've never bothered to check the codes, but your exact symptons are what I experience when my Bipes connector comes loose. The car will die at a seemingly random point. Then it will start and run fine, but simply revving the engine would vibrate the connector and the car would die. A quick push on the connector and I'm back in business. It's only happened on the freeway once though, which is why I have it quick-access style in the glove-box.

Check all your AFTERMARKET electrical connectors.

...and fill out your profile (specifically with where you live) and update your signature with your setup, maybe give us a thrill and post some pics in the vbGarage.

Isn't the 1.6 a open/closed tps rather then a variable one? If it failed I can't imagine a no-start situation. Unplug it and see if it starts. The ecu should set a fixed value for it but failure while running could cause the engine to die.

well i read the manual for a 1990 mx5 so i would assume it's the same for his 92... i dont own one so idont know. Also it should start without one. However is the AFM is faulty it could very well shut him down like that.

To answer your question the 1.6 is an open/close tps(stupid mazda) but it depends on which way the ecu reads the values whether it would start or not. If the ecu read 0 as closed and 1 as open the if the tps is not working it may still read a 0 to the ecu and start but would flip out when giving gas.

now that is all theory