1997 Dodge Neon - 2.0L Runs Rich

[prestigeauto]

Baro reads good with KOEO. Engine idle RPMs = 992, Manifold vacuum = 12.5 iHg, O2 B1S1 = .9 volts, TPS = .67 volts, MAP = 2.47 volts, IAC actual and desired steps = 77, Inj pulse width = 3.86 msec, EVap Purge = 5%.

Customer had car towed here last week because she was afraid to drive it. We had alot of work to do at the time so car sat on the back burner. Fuel pressure a bit lower then specs but does not loose pressure. The spark plugs seals leaked badly. Replaced V/C set and spark plugs and wires and checked compression. All cylinders are around 205 psi. I thought compression reading was only good because of the oil leaking into cylinders however, after running the engine a long time and rechecked compression nothing changed. Dropped the exhaust with no change. I did not verify but tech checked timing marks and said it was right. Called customer to update them and they really don't want to drop alot of money into car so we have discontinued further diagnostics and they are going to pickup on Saturday.

I'm a little crazy and still want to figure out what the problem is even if nobody else does. So I'm posting this for basic theory in computer logic and possible causes.

When engine is idling in closed loop and long and short trims at -25%, shouldn't the IPW be down to 1msec, not 3msec and greater like this car? If actual vacuum is low then the map volts should be respectfully higher? Is the car running rich because of low manifold vacuum or is the manifold vacuum low because it is running rich?

[ricmorin]

12.5 is too low. Low vacuum is causing extra fuel to be dumped. That is why your o2 is .9. That is why your trims are taking fuel away. The car is confused.

Check for the engine being out of time or maybe the exhaust restricted first.

[steven kiser]

i agree with ric. on antother point, the customer should be congradulated. their car has far exceeded it's life expectancy.

[Tim Martin]

Life expectancy? Wasn't aware it had one. Appreciate the update.

[ricmorin]

Life expectancy? Wasn't aware it had one. Appreciate the update.

I have 3 Dodge Neons we use for loaner cars. One is 95, a 98 and the other is a 2000. All run great and take very little to maintain.

[Tim Martin]

Hey Ric. Don't take me serious. I believe in making this business of auto and truck repair alot of fun. We harass any person we come in contact with, customer, sales person, or whoever is a likely possibility. Ask the MAC tool truck guy. He takes the most from us.

Gotta go - work waitin to be done. Coffee just got all.