aarondcounts

I have been trying to solve this mystery for a couple months and now it is critical. I've had declining fuel economy (was getting nearly 40 mpg, now barely getting 20) and major loss of power. I have had Idle Air Control System (not IACv) codes, P0420 (I recently replaced my CAT), had misfire codes but they have not been around for a while. Now I cannot get the car started, for a couple days it would only start if I held my foot down on the throttle. Can anyone guide me to look at to resolve this? I have replaced the spark plugs, I am actually replacing the fuel filter today. Another thing to include is the car broke down on the highway, it down shifted (Automatic Transmission) and would not shift again. The RPMs shot up to 5000 rpms and if I let off the gas it would lose speed quickly, and when I hit the throttle it would hit 5000 rpms and could not maintain speed.

TomCat39

If I recall a P0420 is a Transmission code, Had this code on my Neon a few days before it blew up.

Something about the overdrive... Long story short, had to buy a rebuilt tranny and get it put in.

The tranny sounds like it's in limp mode. Lets you get it off the road or down the street to the shop but not to drive anywhere.

As far as I know you have to get that resolved before you can do anything with the motor side of things.

Former User

Before you replace the cat (P0420) again, you need to do a full ignition system tune up. Otherwise, the new cat won't last long.

aarondcounts

I have replaced fuel filter, dizzy, plugs, wires and I still can't get the thing to turn over. I am getting spark and fuel, but the car sounds like it is firing but never gets to the point of running. I tried applying some throttle when trying to turn it over but still get the same result. I have been told to look at the fuel pump but that didn't sound right when considering the high rpms before it died.

Former User

Is spark bright white at all 4 plugs?

Will the engine start with starting fluid?

Have you checked the mechanical timing and compression tested the cylinders?

aarondcounts

What should the specs be for the compression? I was unable to get it to start with starting fluid. For the spark I will test it tomorrow when I have someone that can try to crank the car as I watch the spark.

Former User

You'll be compression testing a cold engine, so you can't expect spec PSI numbers. What you're looking for is that compression is similar (within 10%) for all cylinders.

aarondcounts

I checked the spark and found that only 1 plug was bright white. I replaced the ignition coil and wires. The spark is now bright white on all the plugs. The car would not start with starter fluid. I found while working through the other issues that the fuel pump was not operating properly and I replaced it. The car now sounds better when it is trying to start but still will not turnover. I will be checking the timing now to see if it is off. Before I started having power and performance issues I had to replace the crankshaft speed sensor.

NotARaCist

iTrader: (1)

Have you gotten around to the compression test yet? That's kind of a critical bit of information at this point, since the motor won't start with starter fluid.

aarondcounts

Checked the timing and it is spot on. The compression test was not good. 2 of the 4 cylinders had no compression. Another thing that was checked is if the liquid on the spark plugs would burn and it would not. I am beginning to wonder if part of the issue is bad fuel.

Former User

Remove the hood ECU fuse and then redo the compression test to rule out flooded cylinders. Also compare the numbers after adding a teaspoon of oil to the cylinders. If cyls 2 and 4 still have no compression, then do a leak down test to see where compression is lost.

aarondcounts

So the issue was know o compression in cylinders 2 and 3. The block is actually cracked between the 2 cylinders. I actually sold it to a local mechanic and bought a new car.