ECM repair & valve seals

[kingfish]

I have a 95 two Geo Tracker auto. the check engine light came on reading the code for bad ECM ( light does not blink ). I asked about it before and someone said that it can repaired easily, or cheaply. How can the ECM be repaired.

Also i think the the valve seals are worn out, are they hard to replace. I suspect this because when sitting for about 2 days or more dark smoke comes out the exhaust. I think oil has to be leaking through and is burned/ blown out upon start up.

[-Lawless]

Have a look here at Jerry's ECM page.
Great info.

[jtgh]

is my page.

the caps can be changed $1 ,get just the one in corner next to connnector.
look for signs. leaks and smoke stain and cracks and bulges on the tank caps.

are you getting the high 53 or higher?
this says power bad , from out side or inside ME.
the cap is open circuited.

is this 16v?

seals ,3 ways:
1: pretend its a diesel and roll.
2: air pressure method ,replace 1 at a time.
3: pull head , replace them.

the fourth i dont recommend, seal softerner, oil additive.

[jtgh]

find guy who can solder.
say remove c111 or c 103 as appr. to valve count and please put it in ,with correct polarity. stripe or arrow is minus.
now even a radio shack cap is 99.9% better then ones blown and dried out.
and if up north (not AZ) then it will go another 15y.

go for the Mouser 85deg C caps if you are a desert cat.

47 uf and 50v 63v or 75v. ok

some cars have 100uf.

[kingfish]

thanks.....it is a 16v with 4-wheel drive(does that make a difference). Would this be a for sure fix or is it more of it might work or might not kind of fix. Either way it beats 300 for a new one.

[jtgh]

good question. 16v
it's just 1 failure.

pull the dome fuse , count to 30 sec. and back in. now it will forget every thing it ever knew. (dome = memory power )
(neg. battery term . same -trick)

now drive ,if (tell us the code please) comes back,and get the code again.
id say replacing the cap is in the 90% likely hood. (if below is ok)

digital repair man on flee bay does it $70 , exchange (send,fix,send back)
others cost more ,have >, (send you, you sendback ,they fix & keep."

c103 really both red DOT caps need changing. It is super easy to do for anyone with PCB solding experience.

another set of issues. Grounds.

the case of the ECU MUST be grounded perfectly (not loose screws) as the case
is used for massive input filtering.

never drive with the ECU loose.

also there are some really critcal grounds under the hood.

the ECU connects to : (dizzy = distributor)
Dizzy base mounts (bundle of grounds at Distributor) all critical. 3 grounds lugs! G109


I will list them all as i do not know which are more important then the others.

The others:

they all have Gnnn numbers
directions driver in his/her seat L or R.
G100 >> R side behind battery
G101 >> R side just front of window washer tank.
G110 >> R side firewall top , just above main harness entry to cab (RHD passenger compartment)
G108 >> fire wall center , at wiper inspection cover.above G109 dizzy.

G111 >>. L side fire wall wiper motor mount.

G103 >> top mount bolt ground , this one going, loose blows up ECU's (battery Minus to starter is #1 critical ground as is G100 ,

if G103 becomes bad (poor starter swap out) this will usually melt G100 ( hidden)
and if it melts real good, then the ECU becomes a toaster. literally.

all above are engine bay grounds.


you never told us the code. DTC fail. Please share this?

This code usaully indicates that he ECU (guessing still) has crashed and it will say
the prom is bad or memory is bad, but most likely it is really a POWER SUPPLY problem.

IN electronics they say never troubleshoot noise, fix the offender first:

One of the hard things to find is an alternator that has a shorted main DIODE inside.
this makes the alternator a huge noise generator. it goes Bang ,bang ,bang.
this noise will find all the bad grounds and bad or weak caps in the ECU.
Please dont swap alternator, my point is , not all problems are easy.
Not all problems can be cured by guessing, some require diagnostic measurements.

in the shop we scope the alternator to find this.

Just dirty corroded battery terminals can cause this.
Just old cracked battery cables that when examined closely are green copper inside and
are ready to completely fail.
ON EFI systems, the Battery is a big filter. so the cables must be good, for the battery to filter out all the Alternator noise (yes, it normally produces pulsating DC ,not pure DC ).

In fact, one can scope an Alternator and see all the diodes working.
converting AC to Pulsating DC.

keep in mind , not all problems can be repaired by swapping parts.
Maybe 1/2?

tell more, this failure is interesting to me, not common at all.

cheers.

[kingfish]

Well when you read the code the check engine is at a constant glow. no blinking. I already reset the memory- pulled fuse,and disconnected battery, but the light never went off.

Sounds like checking the grounds is a good thing to do, i'll have to do that asap.. The part you mentioned about the negative battery cable caught my attention. About a week before the light came on the car wouldn't start to a bad battery. When investigating why it would not start. (lights and stuff still worked, just not enough juice to start.
I discovered that the negative terminal has highly corroded. The rubber covers on the cable seemed to do more harm then good, hid the corrosion from being spotted earlier I just but a new battery in and cleaned of the corrosion.

Would this happen to have caused the problem? Maybe the battery cable is bad?

[jtgh]

sure. but.. who knows right. its a matter of degree.

the ECU is FAILING. 95 car)
no cel (key on )
no codes when commanded,

it is bad or the power to it is bad.


you didnt anwer the question.

KEY ON, DO NOT START is or is not the CEL Glowing.

[kingfish]

Sorry....yes the CEL light is on without starting it just does not blink when code is being read. Sounds to be like a ground problem to me. will be checking out asap.

[-Lawless]

I just quickly scanned the last few posts...
When you say it doesn't flash codes, you do mean after putting in the jumper wire first right?
See here.
Check Engine Lamp stuck ON?