I have a 2004 Pontiac Montana. It cranks but won't start. I changed the fuel filter, and coil packs, plugs and wires. I have good spark and fuel pump works. I'm stumped.... Any ideas?

has water ran down your spark plug wire boots that stick straight up on the heads funneling water into spark plug hole ? this can cause it to not start ) pull the boots up and off several wires look to see if there wet if so dry the holes and wires with papaer towels and stick also is? spark coming from the coil packs check spark see if i jumps from the 2 coil packs check like 4 wires on each coil pack

what you mean is the car turns over won`t fire/start. you need to find out if you are missing fuel or spark. check for codes. if you have no fuel it maybe a pump or plugged fuel filter. if you have no spark then it could be many things. like crank/cam sensor, poor wiring or connections, poor plugs, wires, ignition coil, even possibly a computer. check the first 3 things and go from there.

They are COIL PACKS... No Spark Plug Wires

is the fuel filter clogged?

If this is a sudden occurrence and nothing suspicious happened prior, you most likely lost either gas or spark to the engine. You need to check for both.

Do you hear the fuel pump in the gas tank buzz on for a couple of seconds when you turn the ignition key to ON? Unless the fuel pump turns on and puts gas under high pressure at the fuel injectors, the engine cylinders won't get gas to start. Correct fuel pressure is crucial to know if you have a fuel pump (or fuel filter) problem. If the pressure is correct, it is probably not a fuel problem but a spark problem, although there are less common instances where a fuel injector circuit may malfunction.

The ignition system not producing spark at the spark plugs is the other common problem of no starts. Buy a cheap spark tester at a parts store, plug it into one of your spark plug wires, then crank the engine over and watch for a strong blue spark. You might need a helper to do this. If you see a consistent spark, the ignition system is probably good, although you should probably check more than just one plug wire-sometimes one bad ignition coil in a coil pack will cause no starting. Good luck.

So, do you hear the pump buzz on, when key is on? If that's good, then check your ignition circuit: check for spark at a plug. Use insulated pliers, hold end of plug wire 1/4 inch form engine bolt or ground source. When cranked, you should see a bright blue spark. Yes? Try another plug wire, too. No? Try another plug wire. If you have NO spark, could be your coil, coil pack, crank position sensor, ignition module. I would recommend using a diagnostic flow-chart to go through the ignition circuit. That way, you are not replacing unecessary parts_Expensive! Of course, if you have spark at plugs, your ignition circuit is good! Then you have to look further, like your injector circuit. Good luck.

Yes it is very much possible.But there are many other possibilities too,including starter and spark plugs issue.

If your engine cranks normally but will not start because it has no spark, or it stalls and won't restart because it has no spark.

You can also do a test to confirm the problem .The procedure to do the test is as follows:---

If your engine has spark plug wires, disconnect one of the plug wires from a spark plug and place the end of the wire near a metal surface on the engine. Then insert a small Phillips screwdriver into the end of the wire (the plug boot), or a small bolt or nail to provide a conductive path. Then crank the engine and look for a spark to jump from the screwdriver, bolt or nail in the end of the plug wire to the engine. If you do not see a spark, there is an ignition problem.

OR-----------

If your engine has a coil-on-plug ignition system with no plug wires, In that case remove one of the coils from the spark plug and insert an old spark plug, a spark plug tester or a screwdriver into the end of the coil. Ground the spark plug or plug tester to the engine, then crank the engine and look for a spark. No spark indicates an ignition problem.If the engine has no spark, check for voltage at the coil positive terminal when the ignition key is on. If NO voltage, then problem is on the trigger side of the coil (pickup, crank sensor, ignition module or primary wiring circuit).

But If there is NO voltage at the coil itself, then in that case the problem is on the supply side (the ignition switch or ignition wiring circuit).-----------------

Jeep cranks but no start:----------------

A jeep that cranks over but doesn't start, in many cases will be due to a bad fuel pump, a broken timing belt, an inoperative cam sensor or crank sensor. Also these problems are related to faulty spark plug. Check the spark at spark plugs when you start the jeep. Do you notice any spark. Actually you should see. If in case there is no spark then it's a spark plug problem. Also the coil pack gives power to spark plug. So check the voltage at coil pack. It will show 12 volt. If there is no voltage noticed at coil pack then its faulty coil pack that has to be replaced. If all the possible options checked out ok then check the car starter. The starter gets power from battery to start the jeep. If the starter is faulty then it will not let the car to start. Also check and confirm that there is fuel in the jeep. If its very low fuel then in some cases this causes the problem. Also check and confirm that fuel pump is functioning properly and the fuel filter is not clogged. One of the easiest ways to check for a fuel pump related problem is to spray a little starting fluid into the air intake while trying to start the jeep. If the car starts momentarily, then there's a good chance the fuel pump is not working or the jeep is out of gas. You can also listen for the fuel pump's humming sound when the key is first turned on. Also if a inoperative fuel pump is suspected, a good technician will always check to verify there is power and ground being supplied to the pump, to eliminate the possibility of a bad relay or electrical issue. Fuel pressure can be checked with a pressure gauge and if there is pressure, pulse can be checked at the fuel injectors in several ways including the most common, with the use of noid lights. If the injectors don't have pulse the engine won't start. ---------- This troubleshooting tips will help you to solve the problem. Thanks. Helpmech.

it sounds like either your not getting spark, or fuel at the engine. it could be the coil packs/plug wires or the fuel pump/filter its hard to say what to do first. when you get in the car and turn the ignition on to the position just before turning the engine over you should be able to hear the fuel pump kick on in an attempt the prime the fuel system. if you can smell fuel at the engine after cranking for a few seconds its probably getting fuel. if you have access to an ohm meter with a wire clamp you can test each of your plug wires as you crank it to see if your getting spark. each coil pack sends spark through two plug wires. if you cant read a signal from two of the plug wires trace them back to the coil packs and if they go to the same coil pack that coil pack has gone bad. if they go to separate coil packs you may have two coil packs malfunctioning. this is where i would start i hope it helps.

There are few things that you will have to check. 1) Is the battery properly charged. 2) Are you getting spark at the spark plugs, when you crank the car to start. 3) Is there proper fuel in the car. ---------------- If the battery is not charged properly the car will not start.Check the voltage of the battery .It should be exact 12volt. If there is no spark coming when you crank the engine then its the problem of either the spark plugs or the coil pack.the spark plugs gets power to spark from coil packs.Also check the fuel pump and fuel filter.If the fuel pump and fuel filter are worn out then it will not supply the fuel properly to the engine and this results in no-start problem. If all battery, fuel pump and spark plugs checked out OK then its time to check the wiring connections between the battery to starter and battery to alternator.This will help. Thanks. you can rate this solution and show your appreciation.

Try using some starting fluid in the intake pickup; continue spraying while someone starts the car. If the car starts up, the fuel pump has gone bad.