2002 Intermittent No Start

[illinilefttackle]

Hi Guys-I've been working on cars and trucks since the 50's-but I have a personal vehicle that is driving me nuts! It's a 2002 Hyundai Accent 1.6 liter-4 cyl. automatic. I had it for about 2 years before anything started happening-then it would intermittently crank but not start. I could hear the fuel pump running when I turn the key on-so I would cycle it on and off several times (sometimes this works and some times not). It happens whether cold or hot. No trouble codes. No engine lights. I replaced Plugs and Wires. It has 50,000 on it.
Then I stumbled on to this-if I remove the small rubber hose going to the air intake and spray a small amount of starting fluid in there-it will start right up and run fine-it always runs fine. SO-it's a fuel problem-but which component? It has been to the dealer several times-they cant give me any answers and just want to replace all the sensors and hope it works!-NO WAY. I pride myself in trying fix things myself-but this one is getting to me. It is now starting to get more frequent.
Anybody out there a Tech-or might have had dealings with this kind of thing before? I will really appreciate any ideas-Thanks-AL

[Tractor-Holic]

I know zero about Hyundai's (including how to spell it right!) ,but I have seen a few chevy trucks have the same symptom,a crank but no start condition ,usually after sitting overnight,but a whiff of starting fluid fires them right up and they'll start all day after that usually--next morning the same scenario would repeat..

A friends truck did this and he spent days chasing wires to the fuel pump ,to ensure they were not chafed,corroded,or otherwise "bad",and they were fine--he had 12V getting to the fuel pump,but the advice of several good mechanics said to check the "5 second prime" circuit to the pump,and all involved there checked out good also..he had tried swapping another ignition module he got from a junkyard into it,and for several days he thought that cured it..but it started in again as the weather got colder..testing both modules (original and that used one) showed both as "good"..(The GM ignition modules control both spark AND the pulse for the fuel injectors,and one half can fail while the other remains normal,and do this only some of the time)..

Then one day he asked another good mechanic who worked at a GM dealership and he said "Buy a brand new AC-Delco module,and I bet your problem vanishes..he did,it was nearly 50 bucks,but it started every morning for a year after, that until he passed away from heart disease..

Perhaps your Hyaundi has a similar setup as the GM ??...I'd guess something isn't telling your fuel pump to turn on right away or the injectors..could be a faulty fuel pump relay,or a wire problem..I see lots of rodent damaged underhood wiring around here,and corrosion in weird places deep inside a wire harness,that usually is the source of "computer" problems..too many "mechanics" blame the computer and replace it,or the sensors,when its the WIRES that are defective..dont take much to lose .5 volts in a wire,and a computer senses that voltage loss ,gets a defective reading,and naturally tries compensating for it..

It's problems like these that make me long for the days of points and carbs,and mechanical fuel pumps that two bolts held to the engine,and you didn't need to drop the gas tank to replace one..cars are way too complicated now ,too high tech..too much sensitive electronics on them,IMO..

[merlin5577]

I would also check the battery cables, if one is loose or corroded that would cause a high resistance situation and allow enough amperage to crank the engine but not fire it.... yes, I am speaking from experience.

[RDR]

Does it have a security chip in the key? When you mention turning the key on and off it makes me wonder. Is it just coincidence that when you spray it it starts? Is this multi-port or tbi? If multi-port rig up a test light to an injector wire and see if it is lighting when cranking. Since you have fuel it makes me think something isn't turning it on to the injector. Good luck.

[badfox9389]

I would guess a weak fuel pump, check valve in the fuel pump assy, or a bad fuel regulator. The fuel pump turns on everytime the key is on. So, it thats why it sometimes fires up when you cycle the key it builds enough pressure. Hook a fuel gauge up to it and turn the key to the On but not to start. Fuel pressure should sustain for 30 secs. I don't know the spec for that car but I would guess 30-45psi. If it doesn't hold fuel pressure your problem is one of the things I listed.