98 v6.

Never had any trouble with it before. Backed it out of driveway, parked it on the street. Left it for a few hours. Came out, it started for about 1 second, then just shut off. Would not start again.

Cranks, and cranks, and cranks, but will not start. Occassionaly stumbles a little bit like it wants to fire, but pretty infrequent.

I swapped all 3 relays with known good relays, nothing.

Took dist out, checked resistance, both ways, within spec. Cleaned off dist terminals while it was apart.

Used an ignition spark tester, it jumped the gap that was 2000 or 20000, whatever it is. It was much more than the "bare minimum" required. Seems to be sparking at a constant rate, in time.

Took a test light to an injector clip, they light up what seems to be in time.

Took timing covers off, verified timing is exactly on, on both cams and crank pulley. Did not jump, belt looks fine.

Disconnected fuel line, ran it to a test gauge, it is at 49 psi when you put it on start before ASD shuts off, and when you're cranking it stays at 49 psi until the battery starts dying.

I can't imagine it'd be sparking if crank sensor is bad, and i can't imagine the fuel injectors would be firing if cam sensor was bad.

Any ideas? I'm out of them...

 

CPS ??? Test procedure in the stickies ///

 

If the cam or crank sensor was bad, i wouldn't be getting spark, correct?

I went and tested the spark again last night, i'm getting 30k volts, it'll jump an inch in the tester.

Link me to the sticky you're referring to, i did not see it.

 

Heres the link: https://dodgeforum.com/forum/showthr...r1stGEN+123abc

 

im guessing this is a 420A engine? the car will run with a bad cam sensor, if you unplug it the engine will crank for about ten seconds and then start up. i would say check your compression, and make sure it is good. if it is good do a cylinder leak down test. but your right it will not spark without a crank sensor as far as im aware.

 

fuel pump shut-off is only usually activated in accidents/rollovers etc. Several reasons for no start. The cheapest things first are changing out fuel pump relay or check the fuse whatever applies to rule that out. These fuses and relays are almost always in the engine compartment.
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Try alternator. my truck started in morning i drove to work and after it wouldnt. Got a buddy and jumped it to no avail. So i put my foot to the floor and tried again and it stayed on as long as i had my foot on the gas. I got it home and pulled my alternator out cuz it screamed at me. AutoZone said it was good but i got a new one and it runs like a charm now.

 

Mine was doing the same thing for over a year. One day it would run great and the next it wouldn't start. I replaced all the relays, checked everything just like you did and I finally replaced the cap and rotor. Never had the problem since. I still can't explain why but there must have been something wrong I couldn't see.

 

Let’s review,

You have fuel going to the cylinders, and that was tested: maybe

You have Spark. A bad voltage regulator in the alternator can affect how the spark is given to the ignition coil. Check all connections for the alternator. Not sure how touchy the Avenger is, but could be temperamental and a cause to your issue. Also check all engine/body grounds. May need a Factory Service manual, or good schematics for find them all.

Engine cranks, and stumbles. I am wondering how you are using this word. Will it try to roll over after you stop turning the key?

I would first, pull plugs and see if they are ok, see if fuel is getting into cylinders. If this checks out, then we have one of the basic 3 left. Air.

Check cylinder compression and check mass airflow sensor.

Always check the basic 3, Air, Fuel, and Spark.

From what I have seen in most cars, the ignition system works as follows:

Then ECU controls the fuel and spark based on what position the crank is in by the Crank Angle Sensor. It also knows how to adjust the spark and fuel as well by reading the airflow going through the intake, usually by the mass airflow sensor that is located before the throttle body in most car designs.

When you start your car, the fuel pump is primed, and ECU comes online. You turn the key to engage the starter, and then the ECU will talk to the Igniter or Power transistor to give the ignition coil the charge which then travels the distributor to give the spark plug spark. By reading the Crank Angle Sensor, the ECU knows when to tell the power transistor or igniter to close and complete the circuit to create the charge. Sometimes the Cam Angle sensor is also used for this. The cam angle sensor can also be used to tell the ECU how far to retard or advance the cam in some basic VTEC designs, but I don’t know if the Dodge Avenger ever had that design. It will also warn the ECU of the car jumps time, and turns off the engine, but I have only seen that in Hondas.

Once the engine is started, it will keep the car running in harmony buy knowing what position the crank is in, knowing when to give the coil spark via power transistor/igniter, knowing how much air is flowing and adding and subtracting fuel accordingly. This is a very basic view. Different cars have different ways of doing this. If a balance of vacuum is offset in the plenum or intake manifold, this will also cause adverse conditions causing a non-functioning state. A sensor could be telling the ECU, don’t do this, do this, and stop this. Usually in a case of over complication, it is generally an electrical issue, thus very hard to trace.

I know this is hard, but there are 3 plug wires behind the intake that could be shorting out causing a poor ignition, or even worse, a short to the point of no spark. The hard part is checking this out. You may need to pull the intake to do this, but not sure this could be causing you issue.

When fuel is the source of failure, there are three main things you may need to check. From what I have read, this has already been done. Check fuel pressure, check injectors, and after some cranks, check if fuel is in the cylinders. Easiest way to do this is pull the plugs and smell. Bad thing on this car is that three plugs are behind the intake. Also could be the fuel filter, or fuel screen, but depending where you checked your fuel pressure, this may not be the case. Have a friend crank the car while you check fuel pressure so see if it stays constant, or fluctuates greatly. If it does, replace fuel pump, check filters.

The only thing left would be the ECU, or the wire harness. To check this out, you would either need the Factory Service Manual or the Dealer to test the ECU.

I don’t mean to scare you, just want to give a good path to start down to begin troubleshooting your issue. Hope this helps Good Luck

 

I always seem to come back to this... I have had the same problem in the past with a sticking MAP sensor. Good fuel and fire at the cylinders but only "stumbles". No engine light or code. The MAP (or MAF) is a major player in setting the timing; so in essence, you are way advanced or retarded.

Give it a try...