Jeepster hitting but not running

[rooster]

Had a chance to slow down. Stopped and read the meter's directions. The meter (and I) were on the wrong scale. The battery showed 12.7 volts. I stopped after that little bit of encouragement. I wonder how much money Harbor Freight saved ny eliminating AC and DC from the printing on the two V settings on the meter. Didn't push my luck any further so I don't know if the gray wire has 5V or not. GPster

Do it again. turn key on. place meter on DC volts, measure Gray wire voltage, should be 5V. You could also do the Map sensor the same way on the Gray wire, look for the 12V  Let us know if u get something other than 5v. You could also check the fuel pump relay for voltage, with relay removed (key on) should be 12.7V  Your making progress.

[rooster]

Had a chance to slow down. Stopped and read the meter's directions. The meter (and I) were on the wrong scale. The battery showed 12.7 volts. I stopped after that little bit of encouragement. I wonder how much money Harbor Freight saved ny eliminating AC and DC from the printing on the two V settings on the meter. Didn't push my luck any further so I don't know if the gray wire has 5V or not. GPster

Do it again. turn key on. place meter on DC volts, measure Gray wire voltage, should be 5V. You could also do the Map sensor the same way on the Gray wire, look for the 12V  Let us know if u get something other than 5v. You could also check the fuel pump relay for voltage, with relay removed (key on) should be 12.7V  Your making progress.

Said that wrong , both Gray wires should have 5V . the rely should have 12.7,if you dont get any reading see if grounds are connected.

[wayne petty]

i added some colored lines to the diagram

http://i.imgur.com/gJfCdVK.jpg

there are actually 2 tan and white wires.

one that is the switched output of the fuel pump that is the fuel pump voltage monitor circuit to cavity B2.. the other tan and white wire connects to D1.. that is the Ground connection for the 2 wire oxygen sensor..

[GPster]

Got a little time today so before I forgot how to work my meter correctlyI checked the voltage on the gray wire on the MAP sensor. Got 5 V so the ECM has voltage going to it and does that much right. I got voltage to the instrument panel the other day from the ECM on the wire  to the system check light so I think most on this problem is still about the printed circuit's ground. Maybe some more tomarrow. GPster

[GPster]

Got a little time today so before I forgot how to work my meter correctly. I checked the voltage on the gray wire on the MAP sensor. Got 5 V so the ECM has voltage going to it and does that much right. I got voltage to the instrument panel the other day from the ECM on the wire  to the system check light so I think most on this problem is still about the printed circuit's ground. Maybe some more tomarrow. GPster

[rooster]

Got a little time today so before I forgot how to work my meter correctly. I checked the voltage on the gray wire on the MAP sensor. Got 5 V so the ECM has voltage going to it and does that much right. I got voltage to the instrument panel the other day from the ECM on the wire  to the system check light so I think most on this problem is still about the printed circuit's ground. Maybe some more tomarrow. GPster

Good.
Now that you know the ecm is alive and the dash light (SES)works, you can have the ecm check the system, jump terminal A and B(under dash connector), then turn on key, count the flashes.

[GPster]

Checked the ground wire from the instrument panel to ground today . With the key on the voltage between the ground wire and a chassis ground is 1.7V. I know there is resistence in the bulbs but all of the bulbs are in parallel so you wouldn't think the voltage would crop that much. there would be some resistence across the water temp, oil pressure  and  the gas gauge but this jumble of circuit and these results have proved to me that this is not a valid way to do this test. So I still figure the instrument panel needs to come out. ALL THE TALK ABOUT JUMPING A AND B IN THE UNDER DASH resepticle DOESN'T WORK BECAUSE I CAN'T COUNT HOW MANY TIMES THE LIGHT FLASHES BECAUSE I STILL DON'T HAVE ANY LIGHTS. (caps lock) My under dash recepticle isn't labeled and I looked at my wiring diagram and the colors of wires were labeled with letters but not all the colors were the same as what I have. The wiring diagram only shows four wires and I have six. More harness to be unwrapped. It ran that one time and even took some throttle but with out having  checked all the suggestions I'm afraid to even try it again. GPster

[GPster]

The first dissapointment of the day. While looking at my wiring diagram I saw that one of the wires was called Orange and somewhere I remember Wayne saying that there should be a wire to the computor that is hot all the time and I thought he said orange.  So I went to those four (6) wires at the receptical under the dash (whatever ALDL means) no 12V there. The only power there was with the key on was While/Black(B) to Black/White(A) 5V. Also got 5V from White/Black(B) to ground so the Black/White(A) must be grounded. The extra wires I have are Orange/(? Silver) on G (under A) and Brown(?) on C. D is empty    E looks to be Orange (light Red?) and F Tan/Black (wiring diagram shows Tan/ with Black or White on that circuit). I haven't lost the job of cutting the tape off of this harness.The only wires I'm comfortable with are the Black/White A and the White/Black B. The four other wires are questionable because I can't tell if they are only coming from the instrument panel, only coming from the ECM or are just taps off of wires that go from the instrument panel to/from the ECM as tthe wiring diagram doesn' show them like they should/could be. Even I couldn't mess-up points/carb this bad. GPster

[tomslik]

ok, going by the diagram,
B1 and C16 should have battery power (B+) constantly (for the memory)
A6 should have battery voltage when the key is on
D1,A12,D6,A12 should be grounds

check those AT THE COMPUTER 1st with a GOOD DIGITAL VOLTMETER.
if any or all are NG, fix those 1st

[Arnold]

Buy a code reader. Code readers for those things are like $10. Those cheap blinking/beeping  ones. You don't need a fancy one. Pretty much all those old rinky dink code readers are the same except for the connector.
Plug In code reader.
Do whatever wiring you have to do/want to do until the code reader works.
That's what I would do.
I hate tearing into wiring harness's..and having to play around/back probing..testing etc.,ETC.,
But that's me.

[tomslik]

Buy a code reader. Code readers for those things are like $10. Those cheap blinking/beeping  ones. You don't need a fancy one. Pretty much all those old rinky dink code readers are the same except for the connector.
Plug In code reader.
Do whatever wiring you have to do/want to do until the code reader works.
That's what I would do.
I hate tearing into wiring harness's..and having to play around/back probing..testing etc.,ETC.,
But that's me.

that's IF the 'puter is alive and well,thats why I told him to chk powers and grounds 1st.

[GPster]

That certainly is good advice starting me at the basics. I thought everything with the computor was OK because I was getting the 5V on the gray wire at the MAP. aking your advise but I checked my wiring diagram to make sure I knew where the power was coming from and how. Just went at things with my simple test light as a start and could not find any Orange wires that were hot all the time. My wiring diagrem that showes power to B1 and C16 also shows it powering the fuel pump through the relay and also putting power to the oil switch. I may have seen those components and just thought that they should be on a switched off circuit and I may have jumped that circuit with another Orange circuit. Would be nice if there was some external tap on the computor to check those circuits. The way I had to mount the computor under the Jeepster's dash (inside a gutted glove box) will have me pulling the computor out to get to the terminals. All of the wires are in a big loop so I could bare them to check power but if the colors are wrong or they're in the wrong terminals the checks wont be valid. I guess having it rundidn't mean it was right. GPster

[tomslik]

That certainly is good advice starting me at the basics. I thought everything with the computor was OK because I was getting the 5V on the gray wire at the MAP. aking your advise but I checked my wiring diagram to make sure I knew where the power was coming from and how. Just went at things with my simple test light as a start and could not find any Orange wires that were hot all the time. My wiring diagrem that showes power to B1 and C16 also shows it powering the fuel pump through the relay and also putting power to the oil switch. I may have seen those components and just thought that they should be on a switched off circuit and I may have jumped that circuit with another Orange circuit. Would be nice if there was some external tap on the computor to check those circuits. The way I had to mount the computor under the Jeepster's dash (inside a gutted glove box) will have me pulling the computor out to get to the terminals. All of the wires are in a big loop so I could bare them to check power but if the colors are wrong or they're in the wrong terminals the checks wont be valid. I guess having it rundidn't mean it was right. GPster

dig the 'puter out and check at the connectors, that's the only way to make sure...btw, it DOES have the PROM in it,right?

[GPster]

[quote="tomslik" dig the 'puter out and check at the connectors, that's the only way to make sure...btw, it DOES have the PROM in it,right?[/quote]                  When I removed it  the ECM from the donor vehicle I put it in a plastic bag and stored it inside in a safe place All of the wiring was left intact and labeled for it's location and what it was removed from. The wires were left at their original length with original ends and only the wires to the components that were going to be eliminated were removed from the harness when it's covering was removed. This is part of the reason I have the big loop of wires under the dash at the ECM that I mentioned. I tied my best to not create these problems but it appears to be smarter than I am. GPster

[wayne petty]

i want to know.... did you ever get a chance to print out the wiring diagram... the trouble shooting pages..  the code pages... so you can go thru each code one at a time to verify each circuit..