Need some automotive help

[greymouser7]

I have renewed my respect for the loyal slant six enthusiast-reliable wheels make more since than:

My brother in laws 2004 Kia Optima, almost starts then seems to turnoff immediately. Four cylinder automatic

They don't have a manual. Egr is on order, no apparent in line fuel filter, have been trying to start it with jumper cables attached.

I have replaced the fuel pump and bag/sock inlet filter.

We tore into the dash to get to an ECM -which is supposed to control relays like a fuel pump relay. It seems to catch 6-11 complete piston ignition/combustion firing sequences before it stops.

The father in law says he tested and swapped around the two coil packs and tested them.

I could really use some suggestions.

Thank you for your time and consideration.

 

[Blackbirdsrt78]

it needs to have the codes read and then go from there. usually the most simple thing is the answer. I wouldn't know where to start until I saw what the computer is doing.

 

[Blackbirdsrt78]

sounds like there is a faulty sensor most likely the MAF (Mass airflow sensor) these are easily screwed up from spraying injector cleaner onto them.

 

[slant6billy]

This brings a good point of getting the codes read, owners manual/ service books, car brand on line forum. It will help zero in on the problem. I'll take it to another thread.

 

[brotherGood]

X3 on the codes. These new cars are weird..it could be an auto shutdown because of a bad sensor. There could be a "run all" fuse or relay too.


I know when my 98 ram would do that, it was because the fuel pump wouldn't turn on. We just simply unhooked the battery for about 10 minutes..long enough for it to reset. Hooked it back up, fired it up, and it was good to go.

 

[Jack Meoff]

As mentioned I think you're at the mercy of computer code hell.
Without it telling you what's wrong in the numeric sense it could be a total crapshoot. I'd think any reputable independent local garage would have the toys needed to read the codes so you could narrow down what's going on...

Sorry my man....
In import world that's about the best I've got....

 

[greymouser7]

So he said his scanner erases the codes, and he thinks that the scanner won't work if the motor is not working -is that true?

The parts my father-in-law ordered came in today and yesterday- he asked O'reilly's if he could pick them up both today, the store sent the parts back.

He is an electrician at the TVA power plant, no time to work on the car with his schedule.

I tried telling him cheap OBD2 scanners don't narrow down the fault like dealer or high end mechanic scanners do.

He is afraid of getting ripped off by the mechanic.- I am a passenger in a car wreck-I can do nothing but watch the crash.

 

[Jack Meoff]

You can only lead a horse to water......

 

[Blackbirdsrt78]

they do not erase the codes..unless you clear the history off the computer.ODB2 is OBD2 no matter if it is at a dealership or one you buy yourself. The difference is only in the user interface. The motor does not need to be running to see the history of codes.

 

[Mcfly68]

Code erase erases the history as well ( resets the moniters )...because the car starts and shuts down right away...it may not even set a code...there is a HUGH difference between a code reader and a dealer diag tool...First thing to check.....turn the key on to prime the fuel system...ideally hook up a pressure gauge to the fuel rail...if no gauge available place a rag over the schrader valve and depress it ( extreme caution needed here..saftey glasses recommended etc) to check for fuel pressure...there should be strong pressure...not a dribble..if there is pressure...remove the MAF ( if it isnt a speed density system) and check for any obstructions in the venturi ports...anything in the ports with cause faulty readings ( I have seen spiders, dandelion fluff, dead flies)...DO NOT use compressed air to clean it...gently blow to remove foriegn objects then you can spray some carb cleaner, brake cleaner etc through it holding the can about 8" away from it. if it still starts and stops...have some one start it, and someone else under the hood ready to unplug the maf as soon as the engine starts...if the MAF is faulty, this will throw the system into limp mode and the vehicle will run ( poorly)..getting the timing right on this is a little tricky if not use to it. 90% of the time, a start then stop situation will be a MAF ( normally a fuel pump wont even allow it to start momentarily)...there isnt much else that will cause this...most everything else will cause poor running ( bad coil..tps, cts, map etc).

People rely on codes waaaay to much ( even mechanics ). Perfect example...had a car come in that another mechanic had diaged a bad MAF, because that is what the the computer said. When I got the car, took me about 30 mins to find the problem...the MAP sensor was only reading 12" of vacuum, while a vacuum gauge was reading 19". The computer thought the MAF was bad because it wasnt reading the right volume of air for the amount of load it thought the engine was under. Codes are great but you still have to know how the system works and make basic checks...vacuum, A/C voltage leakage ( more than .25VAC causes all kinds of weird issues with computers and sensors) etc..I fix more problems from people with a code reader and limited knowledge than anything else

 

[greymouser7]

Today when he finally got home he elaborated on his initial trouble shooting:

The code reader said that numbers 2 & 3 cylinders were not firing. He bought a coil pack and swapped them out back and forth ( only two coil packs on motor-each pack powers two cylinders each. ) He has changed plugs and wires. He thinks that the engine control module is bad but I think if you have two cylinders not firing it points back to the only common denominator between the two: coil packs.

Can you start the car with the mass air flow sensor already disconnected? Or do you have to start it and disconnect it simultaneously?

I am going to try to find his scanner and get some codes.

Thanks for all of the help.

 

[greymouser7]

Now that I think about it, I think the coil packs are paired up 1 & 2 and 3 & 4???

 

[Blackbirdsrt78]

Now that I think about it, I think the coil packs are paired up 1 & 2 and 3 & 4???

you need a service manual. not sure how they are paired the initial problem really sounds like a MAF

Congratulations you have an electrical problem!!! check the easy stuff first loose plug wires coil packs check everything. or you may need a new MAF sensor

I could show you how we fix things in Russia....:violent1: just kidding

 

[MiradaMegacab]

Its TBI or FI?
You swapped coils, perhaps swap the fuel injectors.

 

[ramenth]

Computer diag is easier than most people make it out to be. The fixes can vary, but it still come down to spark, fuel, and air.

This car isn't much different than my Hyundai, minus the six versus the four. The Hyundai would start and then go into limp home, if it started at all. Serious lean misfire. Sounds like what you're getting. (I say sounds like, because I'm more of a hands on diagnostician. Trying to diagnose something over the internet sucks.)

Lean misfire means on of two things: too much fuel, not enough air. Think it through. What can cause too much fuel, not enough air? Check all your vacuum sources and any sensors relying on vacuum and air for PID's. (MAP, MAF, even a cracked or broken intake tube running from the throttle body over to the air cleaner

And if you mean misfire on those cylinders, that doesn't necessarily mean those cylinders aren't working, just means that the spark parameters are below threshold. Weak spark.

Wanna a real kicker? When the Hyundai went into limp home it kicked a MAF code. The MAP sensor came unplugged.

Has has been said, a code reader isn't a scanner. Knowing how to read the PIDs and knowing what they mean as you read them is a big help in computer diag. The MAF on the Hyundai was reading 8g/s at idle and when it warmed up it was reading 4g/s. First clue that the MAF wasn't the issue. That lead to checking other things.

Don't throw parts at it. That gets frustrating and does nothing but leave you standing there with an empty wallet, cussing the car, when the problem isn't the car, it's technician error.

Time to haul it to a garage and have someone qualified look at it. Yeah, it may cost you money in labor, but it'll run cheaper in the long run as you're replacing parts that don't need to be replaced.

 

[greymouser7]

THanks Robert, everyone. I was just offering my assistance while on vacation. The father in-law was funding the operation and the brother in-law doesn't know anything about cars.

When the parts were sent back, the father lost most of the forward momentum of motivation. I ran out of time. I did ask to use the code reader and was told no in a round about way. He had some crazy ideas after we replaced a valve cover gasket for the daughter-my sister-in-law's Kia.

The engine light went on in the dash and the code reader lead to a cam sensor- this while I was packing for my 500mile trip back home. I always asked everyone I ever came across car advice/perspective since I could play with hotwheels and am glad to have steered clear of the off-brand foreign makes. I am no Ramenth or Mopar-jesus yet. I didn't have any tools with me and the stuff I had to work with was hit and miss.

When the father was looking-up the code for the daughter's car he said something about oil leaking into the spark plug hole and shorting out....I kept my mouth shut on that theory.

Captain, you can close this thread as I am no longer able to assist the family. I left Chattanooga January 1st. I drove by Richard's on my way home (had dinner) and am getting ready for duty Sunday. I appreciate all of the help guys, you can't save them all, and this one wasn't one of our beloved Mopars or any precious classic.

Robert, he shares a common fear of the mechanically ignorant, getting ripped off at the mechanic's shop.

 

[Jack Meoff]

Case closed.