95 Neon Sohc problem

tobe2be · #1 02-06-2006, 12:03 AM

Ok i was just given a 95 neon as a gift from my in laws (thanks very much sarcasm) but they have taken it to a million and one mechanics and no one can figure out what exactly is going on.

Its got a misfire accross the board doesnt seem specific to one cylinder. I ran a compression test and it throws out 180 across the board. Ran a fuel pressure test 55 psi at idle. But one thing that i have noticed is that when i was checking the exhaust leak it has that when i cover the muffler with my hand it shuts off as if it wasnt breathing correctly. so i thought it was the cat so i did the simple fix that was emptying it out. that didnt solve anything and it still shuts off when you cover the muffler. i ran out of ideas. ive replaced the throttle body. and i even think that the motor was replaced already. what else can it be that im missing thanks in advance

BlazerLT · #2 02-06-2006, 01:08 AM

ok, what shuts off when you cover the tailpipe?

mechhound · #3 02-06-2006, 02:28 AM

If what you are saying is you kill the engine when you cover the exhaust, that is good it means if you do have an exhaust leak it is pretty minor. As far as the misfire why not try some fuel injector cleaner, if it hasn't already been tried extensively.

tobe2be · #4 02-07-2006, 09:44 AM

tried injector cleaner tried motorvac nothin seems to work. and i have never heard of any car that shuts off when you cover the tail pipe. also when she misfires the worse there is like a noice from the intake as if the motor is gasping for air. i tried the intake arm and everything seems to be find. need halp b4 i junk it

BlazerLT · #5 02-07-2006, 09:31 PM

check engine light on?

tobe2be · #6 02-09-2006, 10:09 AM

well found the problem and im going to post it for future refrence to anyone that might have the similar sytoms.

Ended up being that the intake manifold was FILTHY the map sensor was plugged up the idle air control valve was DIRTY and the EGR valve was staying slighty open. so i cleaned the Intake Manifold, Map,IAC valve and i made a gasket to plug up the EGR valve. Car is running as good as it ever will. thanks for you guys help

BlazerLT · #7 02-09-2006, 02:47 PM

Replace the EGR valve or at least clean it.

Removing EGR will actually hurt your performance seeing the engine will detonate more and the compm will pull timing to compensate.

EGR is a detonation and pinging control as well as emmissions.

Also, did you pull your whole intake?

das2123 · #8 02-09-2006, 03:34 PM

Quote:

Originally Posted by BlazerLT

Removing EGR will actually hurt your performance seeing the engine will detonate more and the compm will pull timing to compensate.

People block off the EGR on the neon all the time and don't experience the problems you are suggesting. Mopar even has a block off kit for the neon.

BlazerLT · #9 02-09-2006, 03:49 PM

The EGR system is not only there for emmissions.

http://www.asashop.org/autoinc/nov97/gas.htm

also a good read on detonation and preignition which also states a loss of EGR will cause it

http://www.misterfixit.com/deton.htm

And most of the people blocking it off are actually monitoring there computer while doing it. Plus it will throw a check engine light constantly. Now how are you going to know that something else is wrong when the light is on constantly?

The only way to get around it is to buy a Mopar performace PCM.

When undetectable detonation occurs due to high combustion chamber temperatures, the comp will pull timing and essentially hurt performance and economy.

The EGR is shut off during idle and WOT so having a working EGR system does not hinder performance at all. It is only working during cruise.

Higher combustion chambers can lead to preignition and the EGR system is there to keep temperatures down.

das2123 · #10 02-09-2006, 11:55 PM

^^ You are preaching to the choir with me. I know the advantages and disadvantages of removing and blocking off the EGR. I know dozens and dozens of people who have blocked it off for well over 50,000 miles and are doing just fine. Did you know the 2nd gen neons don't even have the EGR system? Any aftermarket PCM will ignore the EGR not just the Mopar one!

BlazerLT · #11 02-10-2006, 02:08 AM

You sure it is removed or just completely internal.

Also, you can't compare that engine to the first gens.

First gens are designed for EGR operation. The seconds weren't.

You can't just say that because one engine doesn't have it that all engines don't need it. That is just plain wrong.

das2123 · #12 02-11-2006, 09:01 PM

Quote:

Originally Posted by BlazerLT

You sure it is removed or just completely internal.

The tube and solenoid are removed or just blocked off and both run fine.

BlazerLT · #13 02-11-2006, 11:45 PM

No, I am talking about second gens.

They still have an EGR system, it is just completely internal.

das2123 · #14 02-12-2006, 03:41 PM

Quote:

Originally Posted by BlazerLT

No, I am talking about second gens.

They still have an EGR system, it is just completely internal.

Ah! I didn't know that. My knowledge of the neon engine is limited to the first gen because thats what I have.

BlazerLT · #15 02-12-2006, 05:53 PM

The weird thing is that deonation picked up by the knock sensor is not always heard by the human ear.

You could have retarded timing without even knowing it.

The EGR system is only used when cruising and is shut off at idle and over 70% throttle so removing it is not beneficial.

It will increase you fuel economy on the highway.

Just FYI. So many people remove it thinking it robs power but a properly operating system will actually get the most power out of your engine.

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