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Good Crank/Have Fuel pressure/NO IGNITION

51K views 14 replies 10 participants last post by  AUTOSPARK 
#1 ·
Hello fellow Hyundai users/owners.

First I must say I have learned much from all the posts in this forum. I am not a mechanic, just one with common sense with an analytical mindset.

I am attempting to repair my sons 2004 Sonata EF 2.4L Manual Transmission:


I have read all posts relating to the no fuel/spark issues, and I am now leaning towards ECM/ECU replacement. Also leaning towards a used one due to financial situation.



I will start with my Question? Will any ECM from another 2004 Sonata Hyundai EF with manual transmission swap out without reprogramming or any other needs?


Here is where my problem began. Driving to work and vehicle just shut down. Seemed like a lack of fuel, slight sputtering, then just dead.


Vehicle WILL crank over, yet no ignition of fuel. Left for an hour or so..then restarted fine. Revved up for a few minutes..all good...sputtered and died a few hundred feet down the road.


Started my investigation:


1) Checked, double checked, then rechecked and verified that ALL engine compartment and passenger compartment fuses are GOOD.


2)Fuel diagnosis:

Fuel pump getting voltage, checked all wiring all good.

Fuel pump pressurizing fine(found this out as I removed the supply to engine..sprayed all over) Interestingly like many other users I could NOT find a separate fuel filter as shown in my ALL DATA schematics. Traced entire line inch by inch...NOT there. Must be combined on the top of pump assembly...or this vehicle only relies on the "sand filter" attached to bottom of pump? Also there is NO separate fuel pump relay for the manual trans, as it combined with the engine control relay or ECR.

3) Injection diagnosis:

Followed ALL DATA testing and inspection of ignition coil. Checked all wiring harnesses for loose wiring..all good.

Initiated "spark test"..removing coil pack, remove spark plug, reinstall plug on coil, grounding plug to ground, have helper(wife)crank over engine...NO SPARK!!! hmmmm, a place to start!

Primary coil resistance specs=0.78 actual =0.57

Secondary coil resistance specs= approx 20k Ohms, Actual=20.2/20.9k respectively.
Spark plug wires resistance: specs=5.6k Ohms/m =- 20%, Actual=5.7/5.4k respectively.

Power supply to injector harness = battery voltage good!

Spark plug looked good, proper gap. ALL GOOD!



Sensor checks:

I am getting a DTC of P0335(checked with my new INNOVA 3140 OBD1&2 scan tool) which is the CPK or Crank Position Sensor.

Hmm.. didn't really want to deal with its removal due to amount of work.

Marked all belts and pulleys and removed CPK. Followed ALL DATA CPK test and procedures..IE Battery voltage to harness, ground to ECM less than ohms, ECM disconnect and ground resistance to CPK harness= open circuit as specified, disconnect CPK, ECM connected ignition ON, voltage to CPK harness terminal 2 approx 5v..ALL GOOD. Ending answer from ALL DATA...replace CPK. CPK replaced with NEW.

While I was at inspected all belts...Timing belt bad, Alt belt bad, AC belt bad, balance belt good...Replaced all four. Followed ALL DATA and Hyundai USA instruction manuals for timing belt replacement. applied and replied all belts till ALL timing marks were in perfect sync.(even made my own "tool to hold Cams in place.. two small pieces of old timing belt, epoxy to two small wedges, worked great.)

Reassembled all, cleared code… can hear fuel pump working/smell fuel to injectors, engine cranks…NO SPARK, NO IGNITION, NO CAR START? Hmmmmm.

CPK code comes up again? Hmmm, apparently no 4 second CPK and or CMP sensor signal.

Move on to Camshaft Position Sensor. CMP getting Battery voltage, resistance from ECM /CMP terminal ground less than 1 ohm..good! CMP harness to ground less than ohms.. Good. Hmmmm.

Just in case checked the IFS Ignition failure sensor:

Readings good…yet replaced any way as I was getting desperate. Good crank STILL NO SPARK/ NO IGNITION.

Broke out the electrical schematics: MFI Control / Power Distribution / Starting System…can’t see anything I really missed. Can You???

One final thing I should mention. The vehicle was in a minor fender bender. The drivers front panel was badly damaged as was the inner wheel cover housing. When I got the vehicle, the plastic molded wheel well cover was severely damaged and appeared to be rubbing against the engine compartment junction harness leading into the passenger compartment block. No wires are severed or visually damaged. Did a quick continuity test by poking the wires at far ends…all good, no breaks or shorts.

Also I have not be able to gain access to the Engine Control Relay to check. It receives power from main fuse..it sends power to Fuel pump, it sends power to the Injector fuse, and all those are getting power. which leads me to the only logical conclusion that it is OK. ( I do not want to disassemble the counsel to get to it. I can see it touch it..just cannot remove.)

Thank you very much for any help you may provide. I guess I am looking for validation to my findings as I am not a certified mechanic. Also I posted this to help others with a step by step on things to check if they may be experiencing the same issues..

Thanks GGarcia
 
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#2 ·
A very common problem is an intermittent Crank sensor... Usually works when the car first starts than fails shortly thereafter. A scope tied to the pulse lead will show the pulse and then no pulse shortly thereafter. They also can become sensitive to vibration and work/not work... It can also become heat sensitive and intermittent because of this...Check the wiring from this sensor also and move it slightly when the engine IS working...Does it quit?
The ECM relies on this pulse and when it's gone will not provide a pulse to either coil and therefor no spark is generated...
Your ECM is just fine and you will probably have to replace the crank sensor...
Dave
 
#3 ·
Run a compression test. It's possible that the cylinders have been washed down with fuel, causing a loss of compression. A crank sensor can cause this condition.

If the readings are under 100 lbs, pour a couple of spoon fulls of oil in the cylinder, turn over the engine a few times, and check the compression again. Not too much oil, but you need enough to get oil past the dish in the pistons.

If the compression has came up after doing this, replace the plugs, and the engine should run.
 
#4 ·
I appreciate the responses "Yardbird and MyKids04Sonata".
Apologies, I have been working and also repairing my daughters VW Beetle.

Yes Dave as stated in initial post, I have checked all wiring and harness connections. Also I have replaced the CPK or crank sensor...(twice) i installed the gold timing plate backwards the first time). When you say that my "ECM if fine" I have gone through all the motions and inspections... would you be inclined to now think that it may be???

Yardbird, I too worried about the fuel wash down. I have since ran a compression test on all 4 cycl. disconnected ignition coil and fuel pump.. 90-91 psi / 89-90 psi / 88-89 psi / 85-87 psi respectively. I did dry and then 2tsb oil and compression differed by about a 1psi.

I cannot see anything I have missed...Can You??

Freaking ECM is my only last conclusion! going to order a used one ASAP

Thx All...GG
 
#5 ·
It's almost never the ecu. I thought 2.4L engines had a problem with the wiring harness of the crank sensor getting hot and cracking because of the route it has to take out of the timing cover?

Anyway, sounds to me like your ecu is doing its job. You have no spark, the ecu says it's cps failure. If you replaced it twice, then I'd strongly be looking at wiring harness.
 
#6 · (Edited)
I believe jsinton is right with the wiring harness..
I would be VERY suspicious about the wiring harness that was rubbed by the inner fender liner. I'd remove the tape in that area and visually check each wire for physical damage. Two wires touching may "look" OK by checking resistance (open/short) but you might have missed the combination of those two. Can you check for pulses at the crank sensor plug while the engine is cranking? Can you check for pulses going into the ECM also?
Most of KIAs 4 cylinder engines have much higher compression readings than under 91PSI . I'm not sure about the 2.4L but those seam quite low.
There was a recent post about a RIO with problems similar to yours. It would run sometimes and just die..(I'm a moderator at kia-forums.com) The owner finally found an engine motor mount broken putting strain on a harness close by and damaging it. He replaced the mount and repaired the wiring harness...No more intermittent dying... Look closely at ALL the under hood harnesses for any kind of cracked or worn insulation.
I still don't believe it's a bad ECM/ECU... The odds are against it.
Look for the pulses from the Crank sensor...If they are missing you will get no spark from the ECM.
Dave
 
#7 ·
The compression is too low to start. About 100 lbs too low. The cylinders have been washed down. The pistons have dishes in them, so you will have to put in more oil than I posted earlier. You will need enough to fill up the dishes and have it pour onto the rings, then turn the engine over with the plugs out to blow out the excess oil. Taking an air hose and blowing into the cylinders will also help get the excess out.

Keep checking the crank sensor. That was where my problem started.
 
#8 ·
Maybe check this.
I have a 2004 Sonata 2.4 engine.
Have you checked the main belt drive or serpentine belt.
I tried to replace this myself and after 3 installs finally sent the car to a certified Hyundai mechanic.
It would run, but rough when I replaced. Runs as good as ever (rough idle) now since belt now has proper slack between cams.This is an interference engine.Be careful when doing any belt work.
 
#9 ·
Once again thanks for all the input.
Yea, gonna re-re-recheck entire harness wiring that was pinched and fender under the Air duct that was smashed during impact. straightened out metal/frame and all plastic.

Will put more than 2tsp of oil when ready to refire...

Also replaced serpentine with proper spec deflection.

PS: DID try a new/used EMC...Not the problem. #%&*

What are you thoughts on the engine control relay/fuel relay, has any one been able to remove this?? how?? I cannot seem to be access it.

sorry for any delayed responses, as I have been repairing my daughters Beetle, as well as my new ride, A GMC truck
 
#12 ·
Idk if this helps anyone but I thought I would post this because no one ever seems to respond after they have found the fix! I've been working at a Hyundai dealer as my first job in the car business. So at home I've been working on a 2004 sonata 2.4l crank but no start. At first thought the fuel pump was bad because I wasn't getting fuel. Checked spark just for good measure. Nothing. No crank and no spark lead me on a massive pinpoint test chase after confirming the circuits to the ignition and fuel pump were good, my next step was replacing the crankshaft position sensor. So I pulled off the power steering bracket and moved it to the side removed the timing cover, harmonic balancer and timing belt swapped sensors and re- timed the motor. The wires just out of the sensor were indeed chafed Turned the car over and got nothing!! Same problem no spark, no power to the fuel pump. After Piss'n n moning for 15mins and a brief nap I pulled the wiring diagrams back out for the MFI system. And after looking at them for a few minutes realized the crank sensor and cam sensor are powered by the EGR fuse(also ecu fuse) (engine bay fuse box fuse#10 15A) pulled the fuse...BLOWN!! Deffinately popped when the wires from the crank sensor arced out. Replaced fuse and voila she lives another day. Hope that helps anyone else with the same problem! Best of luck
 
#14 ·
Hello my XG 350 V6L turns over but wouldn't start, i've had ignitor sensor changed and it started later went off refused to start again till date. Electrician detected no current in the coils, could not read ECU to ascertain possible problem. Again, While the ignition key is on, other warning lights on the dashboard would come up except 'CHECK ENGINE' which goes off after few seconds. Coils have been changed, plugs and cables are fine, fuel supplies normal. i'm quite sure if light comes stable on the ignition line it would start. Pls house any help? Have been stressed with this whole experience, thinking of shifting my love for Hyundai...should i?
 
#15 ·
could not read ECU to ascertain possible problem. Again, While the ignition key is on, other warning lights on the dashboard would come up except 'CHECK ENGINE'
No comms between the diagnostic tool and the engine ECU, and no engine check light being displayed, is more often than not caused by an ECU power supply issue. The very first thing I would do is switch the ignition on and use a voltmeter to check ALL the fuses, on the dashoard & engine bay fuseboxes (see below). Pay particular attention to the EGR & INJECTOR fuses located on the engine bay fusebox. Are those fuses being supplied with 12V? If not the engine power supply relay probably isn't being switched on.
Circuit component Automotive lighting Product Font Cable


If I helped you fix it, why not...

Your support is greatly appreciated
 
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