If the infinite reading is on the light green or light blue, the wiring is not shorted to ground and the problem is in the ECM.

 

The INJ1 and INJ2 fuses are in the fuse panel on the right end of the dash.

The fuse panel with the fuse locations is shown on page 8A-11-0 of the FSM.

--------- bunch of posts got put up between when I read this and when I replied ---------

The reading should be infinite on the ECM side of the injector connectors (light green and light blue wires). A much lower reading when the ECM is plugged in means the injector driver in the ECM is bad.

The word is spelled "probe" (como probar -- to test). Es sustantivo y verbo en inglés

The only way to be sure that there is nothing strange happening is to duplicate the test on a known good 1986 Corvette (namely, mine). Ignition off. All injectors unplugged. INJ1 and INJ2 fuses in fuse panel. ECM plugged in. Meter on 20K resistance range. Black probe attached to ground (my meter shows "1 . " when the reading is infinite):

 

dont understant. If I disconect the ecm. them is nothing there. that is why i get nothing on reading. so what that pruve. can you explain

just check the green and light blue are the one with no reading.

can ecm be fixd????????????????????????????????

 

thank all ready check the fuse look ok

 

sorry I got now.

my original problem was that the injectors are open all the time.

so one side is always have volts. the other side is always have ground. making my injectors to be open all the time.

but the ground is control to by the ecm. the wire alone have no ground. so the ecm is giving ground all the time.

sorry it take me so long to understand.

I have found my problem.

but like always it will cost me more money.


now what is the best places to get a good used ecm

 

It appears that your ECM is bad.

 

thank you very much this makeit very clear to me now. i was very confuse with all the measurement. but now I understand.

Iam 100% positive that the ecm is bad. thank you all for guiding me true all this test.


at the end i was the one that kill my ecm. when i drop the test light .
something short out and damege the ecm

 

Check you local auto wrecker for a used ECM. It was used in a few other cars.


Year Make Model Engine
1991 CHEVROLET LLV L4 2.5L 2474cc 151cid GAS FI N Engine VIN = E
1991 CHEVROLET S10 L4 2.5L 2474cc 151cid GAS FI N Engine VIN = A
1991 CHEVROLET S10 L4 2.5L 2474cc 151cid GAS FI N Engine VIN = E
1991 GMC SONOMA L4 2.5L 2474cc 151cid GAS FI N Engine VIN = A
1991 GMC SONOMA L4 2.5L 2474cc 151cid GAS FI N Engine VIN = E
1990 CHEVROLET ASTRO L4 2.5L 2474cc 151cid GAS FI N Engine VIN = E
1990 CHEVROLET S10 L4 2.5L 2474cc 151cid GAS FI N Engine VIN = E
1990 GMC S15 L4 2.5L 2474cc 151cid GAS FI N Engine VIN = E
1990 GMC SAFARI L4 2.5L 2474cc 151cid GAS FI N Engine VIN = E
1989 CHEVROLET ASTRO L4 2.5L 2474cc 151cid GAS FI N Engine VIN = E
1989 CHEVROLET CAMARO V8 5.0L 305cid GAS FI N Engine VIN = F
1989 CHEVROLET CAMARO V8 5.7L 350cid GAS FI N Engine VIN = 8
1989 CHEVROLET CORVETTE V8 5.7L 350cid GAS FI N Engine VIN = 8
1989 CHEVROLET S10 L4 2.5L 2474cc 151cid GAS FI N Engine VIN = E
1989 GMC S15 L4 2.5L 2474cc 151cid GAS FI N Engine VIN = E
1989 GMC SAFARI L4 2.5L 2474cc 151cid GAS FI N Engine VIN = E
1989 PONTIAC FIREBIRD FORMULA V8 5.0L 305cid GAS FI N Engine VIN = F
1989 PONTIAC FIREBIRD TRANS AM V8 5.0L 305cid GAS FI N Engine VIN = F
1989 PONTIAC FIREBIRD TRANS AM GTA V8 5.0L 305cid GAS FI N Engine VIN = F
1989 PONTIAC FIREBIRD FORMULA V8 5.7L 350cid GAS FI N Engine VIN = 8
1989 PONTIAC FIREBIRD TRANS AM V8 5.7L 350cid GAS FI N Engine VIN = 8
1989 PONTIAC FIREBIRD TRANS AM GTA V8 5.7L 350cid GAS FI N Engine VIN = 8
1988 CHEVROLET ASTRO L4 2.5L 2474cc 151cid GAS FI N Engine VIN = E
1988 CHEVROLET CAMARO V8 5.0L 305cid GAS FI N Engine VIN = F
1988 CHEVROLET CAMARO V8 5.7L 350cid GAS FI N Engine VIN = 8
1988 CHEVROLET CORVETTE V8 5.7L 350cid GAS FI N Engine VIN = 8
1988 CHEVROLET S10 L4 2.5L 2474cc 151cid GAS FI N Engine VIN = E
1988 CHEVROLET S10 BLAZER L4 2.5L 2474cc 151cid GAS FI N Engine VIN = E
1988 GMC S15 L4 2.5L 2474cc 151cid GAS FI N Engine VIN = E
1988 GMC S15 JIMMY L4 2.5L 2474cc 151cid GAS FI N Engine VIN = E
1988 GMC SAFARI L4 2.5L 2474cc 151cid GAS FI N Engine VIN = E
1988 PONTIAC FIREBIRD TRANS AM V8 5.0L 305cid GAS FI N Engine VIN = F
1988 PONTIAC FIREBIRD V8 5.0L 305cid GAS FI N Engine VIN = F
1988 PONTIAC FIREBIRD TRANS AM V8 5.7L 350cid GAS FI N Engine VIN = 8
1988 PONTIAC FIREBIRD V8 5.7L 350cid GAS FI N Engine VIN = 8
1987 CHEVROLET ASTRO L4 2.5L 2474cc 151cid GAS FI N Engine VIN = E
1987 CHEVROLET CAMARO V8 5.0L 305cid GAS FI N Engine VIN = F
1987 CHEVROLET CAMARO V8 5.7L 350cid GAS FI N Engine VIN = 8
1987 CHEVROLET CORVETTE V8 5.7L 350cid GAS FI N Engine VIN = 8
1987 CHEVROLET S10 L4 2.5L 2474cc 151cid GAS FI N Engine VIN = E
1987 CHEVROLET S10 BLAZER L4 2.5L 2474cc 151cid GAS FI N Engine VIN = E
1987 GMC S15 L4 2.5L 2474cc 151cid GAS FI N Engine VIN = E
1987 GMC S15 JIMMY L4 2.5L 2474cc 151cid GAS FI N Engine VIN = E
1987 GMC SAFARI L4 2.5L 2474cc 151cid GAS FI N Engine VIN = E
1987 PONTIAC FIREBIRD TRANS AM V8 5.0L 305cid GAS FI N Engine VIN = F
1987 PONTIAC FIREBIRD V8 5.0L 305cid GAS FI N Engine VIN = F
1987 PONTIAC FIREBIRD TRANS AM V8 5.7L 350cid GAS FI N Engine VIN = 8
1987 PONTIAC FIREBIRD V8 5.7L 350cid GAS FI N Engine VIN = 8
1986 BUICK SKYHAWK CUSTOM L4 2.0L 122cid GAS FI N Engine VIN = P
1986 BUICK SKYHAWK LIMITED L4 2.0L 122cid GAS FI N Engine VIN = P
1986 BUICK SKYHAWK SPORT L4 2.0L 122cid GAS FI N Engine VIN = P
1986 CADILLAC CIMARRON L4 2.0L 122cid GAS FI N Engine VIN = P
1986 CHEVROLET CAMARO V8 5.0L 305cid GAS FI N Engine VIN = F
1986 CHEVROLET CAVALIER CS L4 2.0L 122cid GAS FI N Engine VIN = P
1986 CHEVROLET CAVALIER RS L4 2.0L 122cid GAS FI N Engine VIN = P
1986 CHEVROLET CAVALIER L4 2.0L 122cid GAS FI N Engine VIN = P
1986 CHEVROLET CORVETTE V8 5.7L 350cid GAS FI N Engine VIN = 8
1986 OLDSMOBILE FIRENZA LC L4 2.0L 122cid GAS FI N Engine VIN = P
1986 OLDSMOBILE FIRENZA LX L4 2.0L 122cid GAS FI N Engine VIN = P
1986 OLDSMOBILE FIRENZA S L4 2.0L 122cid GAS FI N Engine VIN = P
1986 OLDSMOBILE FIRENZA L4 2.0L 122cid GAS FI N Engine VIN = P
1986 PONTIAC FIREBIRD TRANS AM V8 5.0L 305cid GAS FI N Engine VIN = F
1986 PONTIAC SUNBIRD SE L4 2.0L 122cid GAS FI N Engine VIN = P

 

i whent out this morning and found one ecm in a auto wrecker .

here are the pics. the one with the red spots is the new one. also i got a close up pic of the part number of the part.

I find out that the original one I had is a rebuild. and the new one i get is the original part

[IMG][/IMG]
[IMG][/IMG]

cost $150.00
i SAW one on ebay that cost $100 plus $15 shipping.. but in my case shipping is to miami. from there i have one more shipping to pay to panama about $15 more. and 2 weeks waiting.
i pay $20 more. but i have the part all ready with me..

i will try to instal tonight. but I think I have to go with my wife to some of her girlfriends birthday pary..
at list they will have free food

 

You will need to pull the calpak/prom from your ECM and install into new ECM.
Remove the 2 screws on door and you will see it. There is a hinged locking tab on each end of calpak/prom.

 

Before putting in the new ECM I would check that INJ1 and INJ2 fuses are the right amperage, that somebody did not put in a fuse that's too big, just to be safe.

 

that was going to be my next question. thank you for the info

 

good call

 

Too large a fuse would just mean in the event of a short the wires would burn before the fuse blew. Obviously nothing to do with his problems.

 

this is just a thought: if one blue wire was shorted to ground, AND the ecm was defective, would you discover it by checking one wire of the 8 while ecm is disconnected? seems as if you have to verify all of the blue/green wires as having infinite resistance. if I understand, they are connected IN THE ECM. but with ecm out, each wire would have to be verified.

maybe the logic is off track. would not be the first time. but is easy to verify while ecm is out.

*** I think I noticed my error in this argument: the green'blue wires are joined in the harness bundle before the one wire goes to d3 or d9 at ecm, if I can trust the schematic in chart a-3. so, if one is not shorted to ground, the others are ok. ecm connects the two blue/green wires to fire both sides at once. I was over-thinking.

 

The reason I mentioned the fuses is that if an injector coil shorts out or if someone was to short across an injector I would think that the fuse would be sized at or below the current handling rating of the ECM so it would blow before the ECM could be damaged by the overcurrent.

I know that the ECM died when you dropped the test light while you had the paper clip in the injector plug which got me thinking about what if you somehow had shorted across the injector at that moment and the fuse was too big to protect the ECM.

 

I understand your logic, but remember the ECM gives the ground signal. The positive (hot) signal comes thru the fuse panel and not at all thru the ECM.

 

Yes, the positive comes from the fuse, through the injector and then through a solid state switch inside the ECM (a triac or scr or whatever but basically a transistor of some sort). That solid state switch inside the ECM can only handle so much current. The fuse must limit the current to that value.

 

ok guys.

install the new ecm. now i have fuel preasure ok. injector ok, I install new starter motor. no picture sorry.

I crank the car and nothing.

start to check everything again.

the problem , I have no spark on spark plugs.

I did remove the distributor. and install again like 3 days ago. I follow the prosedure and instal tdc align rotor to number one tower on cap. look ok from here

I have no spark

is this have something to do with the new ecm ???????

i also check power to distributor on bat cable and have power ok

but I get no spark at the plug

any ideas.

 

trtttt