97 3.0 Grand Caravan starting problem

:banghead: I have a starting problem i get no spark to my ignition coil.... i replaced the fuel pump,all the relays,fuel,filter,ignition coil, and car battery... i am pretty good with cars but this is just stuping me. the car needed these items thats why i replaced them but what is happining is i go to start the van and the engine turns over but no start. if i try back and forth to turn on the van it eventualy turns on but not all the time. i replaced the pump and fuel filter this weekend and the van drove perfect but all of the sudden i came home and waled back out side and it wouldnt turn back on . i tried for 15 min but had to stop battery was getting low. and when i put my spark tester on the spark plug wire and ground it i see no spark and then it just comes back all of the sudden...PLEASE ANY SUGESTIONS
Thanks
Bill

Do you know how the ASD circuit works? If the PCM doesn't see a good signal from the crankshaft and camshaft sensors as you crank, it will denergise the ASD relay. This cuts off power to the coil, fuel injectors, O2 sensors and fuel pump relay. The engine will crank all day. Just won't start. First I'd recommend inspecting their connections and wire harnesses. If they look good I'd go with changing the crank sensor first then the cam sensor. They are infamous for causing intermittent problems. They cost around $30 each. If you decide to change it make sure you leave the paper spacer on the tip as you insert it.

http://www.autozone.com/az/cds/en_us/0900823d/80/1a/40/96/0900823d801a4096/repairInfoPages.htm

Thankyou for the info... i changed the crankshaft sensor and i drove the car around a bit and it seemed find.So i took the car on the expressway to see how it handles and when i got on and accelerated it was fin around 50mph when i was able to get up to about 70-80mph the van started to buck.There has to be something small that i am not seeing....

I have replaced the following items:
Fuel pump
fuel filter
ignition coil
vechiel speed sensor
crank shaft sensor
fuel pump relay

These parts were replaced because they were going bad but there isnt to much more to change. I am thinking to replace the iac and tps sensor and coolant temp sensor cuz then everything will be new except for cap rotor and wires and i did look at the cap and rotor and they look fine. I am still at a loss so any other advice would be appreciated.

Is it starting consistantly now? Is the Service Engine light coming on?

Can't see the IAC causing stumbling at 70 mph. Rough or no idle maybe. Once you press on the gas pedal the throttle plate opens in the throttlebody and the IAC is no longer in play. The TPS can easily be checked with a multimeter. http://www.autozone.com/az/cds/en_us/0900823d/80/1a/40/4b/0900823d801a404b/repairInfoPages.ht

Tough call to make but, for now I would just drive it around a couple days and see if it goes away on it's own. Maybe the pump needs to break in or the PCM has to get used to the new sensor. If you just can't wait I would go with a new camshaft sensor.

Ok i replaced the iac,tps,.... the iac broke into 4 parts when i took it out, so replaceing that was a good idea. The tps i replaced cuz i have been doing everything else.Now whats going on is the car starts and runs, but when i get onto an express way it starts to buck at 60-75 mph. Its very odd cuz it has never done this before. Also for some stupid reason i kept taking the cap off and looking on the inside of it and it looked good but I must of hit a wire in the right way and it came off the cap. Well the number one was blue on the inside. So I also replaced the cap,rotor and wires. The van is running but its almost like its missing but i have checked it several times since saturday and it all correct.

Also I forgot to say was that I am under the impression that on a 3.0 which i have, the camshaft sensor is part of the distributor and from what i can see you have to replace the hole thing and its a little pricey. Please let me know if I am wrong

Yup, you're right. I forgot that nasty detail. Put the cam sensor on the back burner for now. So to sum it up: the crank sensor fixed the starting issue and now a new problem popped up that it has never had, stumbling at highspeed.

Three questions:> HAVE YOU EVER SEEN THE SERVICE ENGINE LIGHT COME ON during this whole process? > Besides the high speed stumbling is it running great? > When it stumbles does the engine die or just hesitate and run again?

Since you say you've never experienced the high speed bucking, I'd lean toward the theory you induced the problem with one of the parts you changed. High speed bucking/stumbling is usually caused by a weak fuel pump, faulty crankshaft sensor, or a weak coil. You've changed all three. What to do now? You could put the old coil back in. You could connect a fuel pressure gauge and monitor pressure at high speed. You could reseat the crank sensor or try another new one.

My best guess would be low fuel pressure at high speed, especially if the engine just hesitates and doesn't die. Tough to say. Outside my theory, another possibility would be the MAP sensor. It's a big player in determining the air/fuel mixture.

Just to CYA I'd recommend you go to Autozone and have them connect a scanner and check for fault codes whether you're getting an SE light or not. It's free. It would be a shame to spend days troubleshooting only to find out there was a code that could have saved many headaches not to mention $$$$$$.

Well since my last post I took everything that put on the van off. I cleaned everything and made sure nothing was broke. I also replaced the map sensor. I drove the car for 3 days without incident until last night when the check engine light came on. So I took out my scanner and got the code P0300 multi cylinder misfire. So I am at a loss again if any suggestions they would be appreciated.

Do you ever think the world is out to get ya sometimes? I've gotta hit the hay. I'll look into this tomorrow PM. Maybe somebody else can give you a hand in the meantime. Here's a little info: http://www.obd-codes.com/p0300