Very difficult starting

DJM1972

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#1
Make
Hyundai
Model
Elantra
Year
2011
Miles
100000
Engine
1.8
We bought this car back in February I think. One car owner. My girlfriend really wanted this car. And we were tired of looking.

It had a clean car fax, how could we go wrong.

And those were my last famous words. Figured out that the car had been wrecked.

Over the last 5 to 6 months its been hmmm. I had high hopes for this car.

The main issue right now is. I had it check for codes a few months back and there were none. No check engine light either. But over the last few months its began to start very difficult if at all.

What its been doing lately is when you try to start it. It will crank a dozen time and it won't start. Then you try again and it starts right up.

Oh yeah I just put new plugs in it too.
Oh I haven't done a compression test either yet. Not sure when I'll get to this.
Also something else I still have to check into. I noticed recalls on the car fax. I'll look into these more at some point.
 

Bruce

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#2
Good morning.. Happy 4th..
Well, just because this vehicle was involved in an accident don't let that cloud your ownership of the vehicle. Accidents happen all the time and when they do one or vehicles are always involved. I deal with this every day.
Your no start problem.. the compression test.. wait on that.. don't replace anything at this point and put the accident fact in the back of your mind. When the no start is occurring you are going to have to find out what isn't there. Most likely no spark, no fuel.. that simple. So, what diagnostic skills and tools do you have to go the next step?
 

nickb2

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#4
If you find it is to complicated, give to a kid with a phone and he/she will hook it up to the car in no time. Also, if your good with a laptop, this opens up the elm 327 capabilities, but for that, you have to make sure it does PC as well as android. Usually 15$. Sometimes they don't work straight out of the box, return it, try another one. Sometimes these chinese clones don't work, but when they do, way better than a mickey mouse code reader from walmart.

Bruce wrote above well what I think also. (hello to Bruce BTW, welcome back).

What its been doing lately is when you try to start it. It will crank a dozen time and it won't start. Then you try again and it starts right up.

You said this in your initial post, so checking fuel pressure key on engine off on first prime is essential, you may have a loss of fuel pressure or initial fuel prime is not enough. Could be a restricted fuel line due to accident maybe, or something else, but once a second prime gets it going, it is enough to combat it.

You can maybe rent a fuel pressure testor at autozone or simialar, or buy a cheap one at same time you order a elm 327. Both are available on amazone or e bay.


From my experience, when a car starts hard the first try, but starts right up after second try, fuel pressure is often the culprit way before a coil, ckp sensor etc, and if overlooked, could send alot of ppl on a wild goose chase if they overlooked if the car had at least 46psi to start. Best would be 50or so. Speck is 46.9 to 52.6psi.
 

nickb2

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#5
Checking fuel pressure is easy if you have some tooling.

Here is where you tap in with the tester. See "B" of picture below. You will need a fuel line quick disconnect tool, available anywhere they sell parts. But first you need to remove the fuel pump relay, start the car till it dies, then install the tool. Put back in the relay, and proceed to wait a few hours, have a few beers or so. Then just prime the key on and note first fuel pressure. Then shut key off, wait a few more minutes, note leak down of pressure, this will help establish if you have leaking injectors possibly.

Then start the car as usual. If it doesn't start right up, don't try it again, note fuel pressure at time of no start. Then start it again, if as you say, it will start right up, note pressure at time of engine running at idle.

You will see a check engine light appear, no worry, you just bought a elm 327, you can clear the fuel pump circuit code later that was caused by you when you started the car with no FP relay. :D

Screenshot (238).png
 
Last edited:

nickb2

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#6
For leak down pressure, reading should hold for at least 5mins after shutdown of engine.

Here is where the relay is, and it's fuse also. But remove the relay, it's safer to do that than the fuse in case something else powers it once the engine is started, There are some car that bypass the fuse portion and still control the relay. I am not saying this is sure for your car, it is just a precaution I take since getting caught a few time with some american oil pressure switch bypasses and such.

Screenshot (239).png
 

nickb2

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#7
Forgot to mention, the fuel pressure tester needs to be installed in "series" at that location to allow engine to run AND read actual fuel line pressure on pressure side.

Reading here also lets us know if the regulator is working well also. If my memory serves right here, the regulator also serves as a check valve to keep residual FP up when engine off. Since this a return-less system, the regulator and fuel filter is part of the FP assembly in the tank and not serviceable as a single part like back in the day when they were bolted onto the supply line to the injectors. But that is for another discussion in the open forums. Older carb systems had a check valve in line with the fuel supply just before the carb to keep the floats up for quick start. Same applies to injection systems, but just located in different places.

Sadly, this type of system is harder to diagnose since you can't pinch a return line to help rule out leak down from crusty injectors, or a bad regulator letting fuel back into the tank over night or at a stop at grandma's.