Engine is not starting... tried almost everything...

[djpast]

Well heres the situation... my car has been running great... i was driving around all day when i get to my friends house i turn the car off, the turbo timer does its 30 second thing (it was a short drive) and i walk inside. no more then 15 mins later i walk out and get into my car... give it a crank... and it just cranks..... and cranks,,,, and doesnt fire.

So,,, i get out some tools and start doing some checking...
*Fuel Pump: GOOD
*Fuel Filter: GOOD (Replaced just in case)
*Spark: GOOD (shocked the crap out of myself *NOTE* remove hand from frame when doing spark test)
*Compression: GOOD (same as it was two weeks ago (155-160))
*Spark Plugs/Wires: GOOD (but i changed them to another known good set i had around)
*TIMING is perfect

Couple things i noticed:
*cylinder 4 spark plug was extremely fouled (not wet, but covered in carbon), while the rest where spotless.
*after all the cranking i did, the spark plugs were not noticably wet... no gas whatsoever that i could see...

SOOOOO i take ecu out and take a look at the caps... crap a lil bit of leakage... not too bad but noticable.... So i take the ECU to a friends house and throw it in his 91. After 1 try it starts right up. so i am thinking crap, its not the ECU after all, back to the drawing board. so i wanna test again if the spark plugs get wet... so i go back to the car, throw in the ECU, and bam, it fires up first try.... i am like WTF?!?!? i restart and turn it off for the next half hour trying to duplicate the problem and it doesnt come back.... Hmmm

Soooooo we fast forward almost 24 hours... i get home, turn off the car... not even left it for 30-45 mins, and it wont start again.... same exact symptoms! So as of right now, i have checked the following to be good:

Fuel Filter
Fuel Pump
FPR
S-AFC Connections
CAS
MAF
Compression
Timing
Spark & Components
Coolant Temp Sensor
Battery
Starter

So i am left with the ECU as far as parts left for combustion. i am pretty damn sure its the ECU because:
1) the leaking caps
2) the injectors dont seem to be firing or opening
3) there is lil to no gas smell in the exhaust to signify fuel is being sprayed
4) the spark plugs are dry as far as i can tell
5) niether one of my dataloggers will connect to the stupid car


CAN it be anything else BESIDES the ECU?? Like a malfunctioning turbo timer or such? (i wouldnt imagine so)

A friend is coming over with his talon to change out ECUs to see if thats the problem... If not.... what other option is there???

 

[djpast]

UPDATE: cleaned Cap poo off board with some rubbing alchohol and qtips... put it back in car.... lil more of a fuel smell this time and 1 of the sparkplugs got a lil wet (not enough to be that noticable) but still doesnt start up... could just be a coincidence...


do you think its too late to change the caps? or do you think the ECU is salvagable? (its an EPROM so i damn hope so)

 

[djpast]

update: it was the ecu. i threw in my friends and it started right up. i have another ecu on the way and hopefully i can fix my old one cuz its an eprom.

 

[djpast]

update number 2: so maybe it wasnt the ECU! 3 days of perfect running later after throwing the new one in it has the same problem... dammit back to square one. i even got it to start up once.... ran and idled perfect. turned it off and tried 30 mins later and back to no start again. WTF?!?!

 

[REDBLUR]

Check the relay on your fuel pump rewire. I had a similar problem last year which came down to a loose wire. You should hear the relay clicking when your trying to crank over the vehicle. Grab the wires by the relay and pump, and move them around as someone is cranking over the engire, it could be a loose/broken wire.

 

[teme]

U should always read fault codes from the ECU before making anything... It's alot more easier that way

read em' codes

 

[djpast]

Check the relay on your fuel pump rewire. I had a similar problem last year which came down to a loose wire. You should hear the relay clicking when your trying to crank over the vehicle. Grab the wires by the relay and pump, and move them around as someone is cranking over the engire, it could be a loose/broken wire.

i have my fuel pump rewired, and i tested it already by jumping the factory wire up in the engine bay to turn the pump on thanks for the suggestion

U should always read fault codes from the ECU before making anything... It's alot more easier that way read em' codes

i have 2 different dataloggers, TMO and PNS and niether one shows any codes from the ECU nor a CEL thanks for the suggestion! keep em up.

 

[REDBLUR]

How did you check the CAS? I would pull it off (make marks for timing and on tabs so it isn't put back in out of phase) and with the ignition key on spin it manually. Test for spark in each cylinder and you should hear each injector firing.

Could it be that you have a small fuel leak which is bleeding off pressure making it not start? I would check the FPR too.

 

[djpast]

So i was thinking in order to diagnose this, i need to know EVERYTHING that is required to start up a 1g DSM car. I think this is everything. What boggles me is that after i threw in the New ECU is that it worked for 3 days and then stopped completely... same with my old one, it worked for a couple days and then stopped completely... and both times everythign was runnign fine til i stopped the car and let it sit and then trying to restart it agian.

Compression
Correct Crank/Cam Timing
Spark
-Spark Plugs
-Spark Plug Wires
-Coil Packs
-Power Transister
Fuel
-Fuel Pump
-Fuel Filter
-Fuel Pressure at Rail
-Fuel Pressure Regulator
-Fuel Injectors
MPI Fuse
MPI Relay
MAS (plugged in and working)
Sensors
-Coolant Temp Sensor (plugged in and working)
-CAS (Cam Angle Sensor)
-Intake Cam has to turn
ECU
-plugged in
-no bad caps
Starter
Battery (good charge)
EXTREMELY LARGE Boost/vac Leak

 

[REDBLUR]

Looks like that pretty much covers it. Although you should be able to start the car and let it idle without the MAS plugged in, wouldn't get to hung up on that one.

Good luck,

 

[igopoopy]

do you have gas jk

 

[djpast]

update 3: well i get to my friends house where the car has been sitting all night (i had tried to start it when i left his house last night one last time to no avail) and bam it starts right up. i drive it the 30 miles home and the car is still up to par as far as as fast as it ever was, smoking my friends h22a civic on the way home.

i just got her home and will check it over the next couple of hours to see if its gonna do it again.

ps - intermintent problems blow to diagnose.

 

[tsunari]

Hmmm. Sounds to me like perhaps one of your sensors is a bit flakey or maybe just not completely connected. I know when I first rebuild my engine, I did not QUITE get the connector to the alternator plugged in FULLY (it wouldn't fall out, but still wasn't plugged in ALL of the way) and because of this, I had weird charging problems. After I plugged it in all of the way (by a stroke of luck) everything was fine and have not had a problem since.

The tests you've done so far seem to be fairly thorough . . . a couple of things I would suggest is check the connectors to your cam angle sensor, crank angle sensor, coil pack, etc . . . one may be loose.

Another is, next time it wont start (if you have the time), check and see if your fuel rail has pressure/fuel.

Give that a go and let us know if anything changes. I'll continue to wrack my brain for ya and maybe come up with something else. (Gotta love intermittent problems . . . )

 

[djpast]

This morning it would not start. i am hoping when i get home that it will not start again so i can start diagnosing.

Interesting developement however. When i was leaving my friends house to drive her home, the check engine light remained on for a couple minutes and then disappeared. I made a note of it to check it out when i got home. when plugging in my datalogger, i got two codes.... speed sensor (24) and fuel pump (42)... when checking out my haynes/chilton manual, the 42 code is the one that concerns me, as it says check the harness (already did) and the MFI relay... hmmmm

I pulled the battery and cleared the codes, when i started it back up only the fuel pump code came back on. now heres my theory... from reading on here and other forums, the mfi relay gives the ECU its power... so if the relay is freaking out, the ecu might not be getting power intermintently. or it might not be sending the signal to the injectors to open. I am going to the wreckign yard to pick up another one to see if it helps...

 

[djpast]

update 4 and final i hope: sooooo. i replaced the MFI relay and still the same problem, but it seemed to be dumping a S__load more fuel into the system.... hmm. so i figure what the hell i will check the coolant sensor wires one more time....

i check the wires.... 0v... wtf... mind you, i checked that damn thing at least 4 times previous... i checked it at the ecu... 4.7v... wayyyyy withing spec. i spliced into the wire about 2 inches above the harness and bam, 4.7v. the DAMN plug was bad. sooooo i go about making my own harness out of female spade connectors, wrap em up real well and test fit them on the sensor.... cool they fit. i take the top one off (the one with the voltage) to check a second time to make sure the thing still has connectivity and bam.... of comes the male spade part of the sensor... DAMMIT time for a new sensor. ARGHH...
and my datalogger telles me the coolant is -70*F, so we know its bad...

soooo we fast forward to today... a new sensor and some wire cleanup later...

[we pause at this moment in the story for a side story- yesterday when doing all these checks with the datalogger and such, i had my car in the ON position. when i get home today, what is my car still in 24 hours later.... THE FREAKING ON POSITION!!! ARGHH ON DEAD BATTERIES!!!]

so like i was saying... a new sensor and some wire cleanup later... AND a jump later... the car is running again perfectly again (currently *does cross*) and things are looking up in the world.

 

[Golden GSX]

I'm having this exact problem. Put in the new sensor, still no go. How do I test the wires for voltage at the ecu and at the sensor?

 

[djpast]

i usually unplugged the sensor and put the positive probe in one of the two sockets in the plug and the negative probe on a ground. til i find the one that is the positive.... and then i pull the ecu out to the passenger side floor panel, leave everything plugged and poke the positive probe into the plug (pin whatever, check the vfaq) and the negative on the ground and check again.

 

[Golden GSX]

thanks for the reply. I got 4.6v on the wire. New coolant temp sensor, good battery, new spark plugs. Still the car just sputters for a couple seconds if I get lucky. Guess I need to wait for my logger.

 

[tsunari]

thanks for the reply. I got 4.6v on the wire. New coolant temp sensor, good battery, new spark plugs. Still the car just sputters for a couple seconds if I get lucky. Guess I need to wait for my logger.

Just an idea . . . if it's the O2 sensor, wouldn't you be able to floor the throttle to get the ECU to kick into openloop mode and the engine should run fine once there? I know this isn't exactly a GOOD thing to do on a cold engine, but just an idea to help troubleshoot . . .

 

[djpast]

more then likely its your ecu then.

 

[Golden GSX]

The ECU will cause the car to have problems starting if it's cold?