85 150 custom turns over but wont fire
Thread Starter
Joined: Jul 2005
Posts: 2
Likes: 0
85 150 custom turns over but wont fire
ok, heres the deal.
Yesterday i bought an 85 ram 150 custom (318ci, 2bbl) for $ 200 that I plan on running in a derby. It ran fine this morning but today(on the advice of my buddy) I removed what I thought was useless wiring in the vehicle ...everythign except for the ignition wiring, or so I thought. I removed the entire inside of the cab except for the wires in the steering column that go through the firewall. I must have clipped some impotrant wire though because now the truck wont even turn over when I use the key, It will however turn over if I jump the solenoid by the battery, but wont fire at all. I am not sure why it isnt getting a spark.
The coil is getting 12 volts of electricity, but the spark plugs arent sparking. I want to make the ignition system as simple as possible for the derby but dont think that I can do it if I cant figure out why it wont even spark.
Is there some sort of computer that controls the ignition? if so where is it and how would I rewire it simply so that it worked? I know alot about the old point's engines from the 60's but this electronic ignition crap is stumping me.
If anyone has wiring diagrams, suggestions, ways of testing to see what is wrong or whatever else, please let me know.
Thanks!
Ted.
Yesterday i bought an 85 ram 150 custom (318ci, 2bbl) for $ 200 that I plan on running in a derby. It ran fine this morning but today(on the advice of my buddy) I removed what I thought was useless wiring in the vehicle ...everythign except for the ignition wiring, or so I thought. I removed the entire inside of the cab except for the wires in the steering column that go through the firewall. I must have clipped some impotrant wire though because now the truck wont even turn over when I use the key, It will however turn over if I jump the solenoid by the battery, but wont fire at all. I am not sure why it isnt getting a spark.
The coil is getting 12 volts of electricity, but the spark plugs arent sparking. I want to make the ignition system as simple as possible for the derby but dont think that I can do it if I cant figure out why it wont even spark.
Is there some sort of computer that controls the ignition? if so where is it and how would I rewire it simply so that it worked? I know alot about the old point's engines from the 60's but this electronic ignition crap is stumping me.
If anyone has wiring diagrams, suggestions, ways of testing to see what is wrong or whatever else, please let me know.
Thanks!
Ted.
Champion
Joined: Feb 2005
Posts: 3,710
Likes: 2
From: Skagit County, WA
RE: 85 150 custom turns over but wont fire
There are a couple of things to check.
If it's an auto there should be a shift interlock or whatever that will prevent it from starting if it thinks it's in gear, or if it's a manual there should be something to keep it from starting if the clutch isn't depressed. There is an ECM in the engine compartment that needs to stay hooked up, on my 86 w250 it's on the firewall over by the driver's fender. It'll look like so:
Those can go bad, I had one fail while I was driving down the freeway. It would allow the engine to spin but not fire. I'm not sure how you test that other than by swapping in a new one.
If it's an auto there should be a shift interlock or whatever that will prevent it from starting if it thinks it's in gear, or if it's a manual there should be something to keep it from starting if the clutch isn't depressed. There is an ECM in the engine compartment that needs to stay hooked up, on my 86 w250 it's on the firewall over by the driver's fender. It'll look like so:
Those can go bad, I had one fail while I was driving down the freeway. It would allow the engine to spin but not fire. I'm not sure how you test that other than by swapping in a new one.
Thread Starter
Joined: Jul 2005
Posts: 2
Likes: 0
RE: 85 150 custom turns over but wont fire
Yeah, my ram has that type of ignition system, NOT the spark control computer system.
We got the wiring diagrams today for the ignition system and traced the schematic. everything sems to be energizing now, but there sill is no spark. The electronic control unit is giving the dual pickup relay about 9 or 10 volts, the coil is getting a constant 12 volts, and seems to be giving the distributor power, yet it still wont fire.
The only thing that we found wrong with the wiring had to do with an orange wire comming from the ignition switch. Apparantly once the wire goes through the firewall it splits...one wire going to the starter relay and the other going to the dual pickup relay. THe wire goign to the dual pickup relay is cut off at the firewall, although I cant find a place where it would plug in at the dual pickup relay. Moreover, the dual pickup realy...(I think that is what it is inside the distrubutor cap) is getting power from the ecu...about 10 volts anyhow, so why would it need 12 from the ignition switch? I am confused and frustrated.
Is this thing ,the dual pickup relay, inside of the distrubutor to begin with or am I looking at the wrong thing? From what I see, it must be, but then the wiring diagram would be slightly wrong because a few wires dont match up in color.
I am pretty sure that everything is working fine, it just seems that somethign isnt grounded or isnt getting power..or not enough. Is there anything else that I am overlooking or should review?
Thanks again,
Ted.
We got the wiring diagrams today for the ignition system and traced the schematic. everything sems to be energizing now, but there sill is no spark. The electronic control unit is giving the dual pickup relay about 9 or 10 volts, the coil is getting a constant 12 volts, and seems to be giving the distributor power, yet it still wont fire.
The only thing that we found wrong with the wiring had to do with an orange wire comming from the ignition switch. Apparantly once the wire goes through the firewall it splits...one wire going to the starter relay and the other going to the dual pickup relay. THe wire goign to the dual pickup relay is cut off at the firewall, although I cant find a place where it would plug in at the dual pickup relay. Moreover, the dual pickup realy...(I think that is what it is inside the distrubutor cap) is getting power from the ecu...about 10 volts anyhow, so why would it need 12 from the ignition switch? I am confused and frustrated.
Is this thing ,the dual pickup relay, inside of the distrubutor to begin with or am I looking at the wrong thing? From what I see, it must be, but then the wiring diagram would be slightly wrong because a few wires dont match up in color.
I am pretty sure that everything is working fine, it just seems that somethign isnt grounded or isnt getting power..or not enough. Is there anything else that I am overlooking or should review?
Thanks again,
Ted.
