Van help

Having troubles with my fathers 92 plymouth van its got a 3.3V6 thats not starting anymore. It's got all 3 pieces of the puzzle air,fuel and spark.But it just wont fire, some one told me its one of the sensors.

How do you check if a sensor is working? i have a multimeter but i dont know how to "check" a sensor.which ones should i check ,TPS?


thanks

 

You need a code reader to check out the trouble codes first. Then you can check out which problem areas the codes tell you aren't in spec.....

 

His van is an OBD I Chrystler system. For him to read the codes you need to quickly turn the key switch on and off 3 times, (don't enguage the starter, and it has to be done within I believe 30 seconds) and look at the service engine light.

The light will flash the code, kind of like morse code it will do a number of flashes a pause and then more flashes, you need to count the short flashes because they make up your code numbers and the pause between the flashes differentiate the numbers. (in other words 3 short flashes, pause, 5 short flashes would be 35) if I remember correctly it repeates the code three times and from there you can go and look up the codes here
http://www.allpar.com/fix/80s-codes.html

Also the next question I have to ask is how much fuel pressure is coming through the fuel lines. You may be getting fuel but not enough to satisfy a TPI fuel injection system, this will not show up on a engine code. Also another one that will not show up is if your fuel pressure regulator is bad. The fuel pressure regulator is a vacuum diaphragm and if that is bad it will either force too much fuel into your cylinders if it is stuck in the closed position or too little if it is stuck in the open position.

Also check the position of your IAC idle air control valve, it is on your butterfly body they get used and go out of the adjustment range and no longer work. This is what it looks like
http://www.autozone.com/R,2456635/v...partType,00207/shopping/partProductDetail.htm
The solonoid self adjusts the tip so it meters the amount of air drawn into the motor at Idle creating the proper fuel/air/spark ratio. The tip wears out after time and go's out of the adjustment range so you will not be able to start the van, but the solonoid is still operating properly so it will not show an error code.
If you have no check engine lights I am more inclined to believe it is the fuel pump or the IAC valve I have seen similar scenarios and it has turned out to be one of those most of the time.

 

As a note if you have spark both your camshaft and crankshaft sensors are working correctly, they tell the computer when to start the firing sequence...
If your timing is off on the motor then they will operate correctly, no error codes will show up and the engine will not start. If I remember correctly they still used the stupid plastic timing gears on those motors so one of those could have failed or you could have skipped a tooth. Check all of your vacume lines and make sure none of them are broke because they control the fuel pressure and several other sensors, like the map sensors and such....
Also as a note if you don't have a check engine warning light show up then there will be no codes for the code reader to read so if you are on a tight budget make sure there are some codes to read before you spend money buying one, unless you want one, they are always good to have in the toolbox.

 

I just found this site this should help you out

http://www.aa1car.com/library/2003/us60324.htm

 

thanks, the only light that turns on is a "check gauges" light.

 

This site tells you how to check the fuel pump, start there, the last Chrystler product I had required an 85psi pump (jeep wranlger) and it went weak on me, psi dropped to about 35 and it no longer ran. You can buy a fuel pressure tester fairly cheap in comparison to swapping sensors.

http://www.partsamerica.com/ProductDetail.aspx?MfrCode=EQU&MfrPartNumber=3640&CategoryCode=3390

http://www.autozone.com/R,572107/store,872/shopping/accessoryProductDetail.htm

 

I'm going to go get a pressure gauge right now,the one i have only goes up to 15psi.

The engine light finally lit up and i tried the key thing and i got a 1255 code, i'm going to check it on the website.

Thanks again

 

cool I hope you find the problem

 

well my sisters boyfriend came out and checked the fuel pressure and it checked out, but we cant figure out the codes the ones we keep getting are 12 and 55 but on the site this is what they say:

12 Battery or computer recently disconnected (will occur on most cars most of the time, it indicates a low / missing battery happened in the last 50 key starts. Don't worry about it. — Tom Wand)

55 End of codes

 

ok need to get back to basics. first how did you determine that it has fuel (as in fuel geting into the cylinders). B. how did you determine you have spark? At the auto parts stores there is a tool called a noid light. its basicly a light bulb you can plug into the injector pulgs that will flash when the computer is trigering the injectors. if you get one of these you can tell if the compter system is working. Waiting to here some more info to give you more help.

 

First pull the plugs and see what they look like, be it wet, white, brown..If they are heavily covered or too far out of gap it won't fire. If you want to test your spark plugs you can get one of these and it will show it is firing
http://www.jcwhitney.com/webapp/wcs..._ID:2004216&productId=2004216&catalogId=10101

you still might have the wrong gap or a fouled plug though.

 

well my dads getting rid of the van. He alredy got another car its a 96 camry with a slant four.

 

I have had plenty of mopars over the years. Run fine/park it/next start up...no go.Tear hair out for 2 hrs searching for problem...finally just throw a set of plugs at it and viola!!! it runs again.Could be your problem.(recently had a frickin neon do this to me as well)Only took 15 minutes of hair pulling this time though.

 

Quit using Champion plugs and switch to Autolites.