i have a 95 dohc...sometimes when i try to start it just cranks and cranks...usually not if its cold outside, its worse the hotter the temp is or if i ran the a/c...usually only does if the car was off for 20-30 min or more...any ideas? i have already changed the plugs and coolant temp sensor and the wires are newer belden powermax.

It sounds like a vapor lock issue, although this isn't a common problem anymore. Vapor lock is caused when fuel in the fuel line turns from a liquid to vapor making it difficult for the fuel pump to deliver fuel to the engine. The fuel can be vaporized after being exposed to hot temperatures. It may be worth checking the operation of the engine cooling fan to determine if excessive heat is causing the problem. I'm not an expert, so I hope someone more knowledgable can weigh in. Good luck.

thanks for the response, apparrently this isnt a common problem with so many views and only 1 response.my engine stays plenty cool though, i have an aftermarket electric fan that is very efficient and temp stays low to mid never high, even at idle with a/c going. my problem only happens regularly when the outside air temp is hot otherwise only every so often if i crank it, it starts right up, but the idle is really low so it will die. then i crank again it starts and runs great. this only happens about once a month though. on the other hand, if its very hot then i will have to crank 2-3 times for 10 sec or so each time then it will usually start idle @ about 400 rpm or so and die. then i crank again, it starts right up and runs great...anyone???????? any help would be great, my wifes 96 villager does this as well but hers does it every day regardless of temp, again ive tried a tune-up and coolant temp sensor but nothing helped! <img src="/forums/images/graemlins/confused.gif" alt="" />

I don't know if our two problems are related, but at random mine will be a pain to start as well. It doesn't seem to be connected to heat or the weather or anything, but then it hasn't happened yet this winter. When this happens the quickest way I've found to get it started is to hold the gas pedal to the floor and crank it (I've heard injected vehicles have a "flood clearing" setting at WOT and cranking?). When it does start it'll run terribly for a few seconds (by now I've let up a little on the pedal) and then off we go as if nothing happened.
Here's a shot in the dark: (input anyone?)
Could a mass airflow sensor stuck open a bit cause this kind of issue? I couldn't hurt to have a peek at it as it may be in need of a cleaning (unless this happened on your tune-up)
I really doubt this helps any but might get others thinking to at least shoot down my MAF theory.
Good luck!

the mas flow sesor is a sensor not a valve, if it is dirty it can cause promblems as well if the throttle body is dirty. use mass flow cleaner on it not carb cleaner ! the problem of the truck running bad when you start woith the pedal to the floor is the computer ecm go nuts trying to figure out what went wrong.

I would replace the fuel filter, clean the trottle body, the mass flow sensor but be easy on it or you will damage it! replace the plugs it not done lately.
? do uou have a high low setting on the fan ? if it is always on high it could be cooling the engine to much.

John

a complete shot in the dark..but could the fuel pressure be leaking down? next time this happens try turning the key from off to run but not start then attempt to start it. chevy astros had a problem where the fpr would leak down the pressure making for difficult starts. i could be your injectors or fuel regulator leaking down pressure so when u go to start it theres no fuel at the rail...again...a complete guess but heck its better then no response right?

thanks for the response guys, looks like i was on the same path as all of you..i have cleaned the maf with crc maf cleaner, plugs were done about 3000 miles ago, ngk v powers, fan has a by-pass switch, no high or low, but i turn it on as the engine gets warm, never let it get hot and turn it off when it cools. ive tried leaving the key on for 20 sec or so before cranking but didnt help..didnt try the throttle body yet forgot about that 1, or the fuel filter on the kia since it seems like a pain, but i did change the fuel filter on the mercury and it didnt help much if at all but guess ill try it when i have some free time and it warms up a bit, its been cold lately <img src="/forums/images/graemlins/baby.gif" alt="" />....any other suggestions would be great, again thanks