Come on gus I really need some help

I've been asking about getting this 90 ram 50 running. I have totally redid the inside with new carpet and seats, cleaned and replaced all the plastic and got all the fuses and lights working. The new ecm came today and I put it in. checked the coil for spark and yea I had spark at the coil. Hooked the coil to the distributor and tried to start it. No joy. Tried several times hoping it was just waiting for l to get to the injectors. After 3 or 4 tries I retested the coil. Now I have no spark until I release the key from the start position, then it sparks one time. Did I ruin the new ECM. What''s next, only code now is 15. checked the plug and all is correct.

I ment GUYS not GUS. I don't even know a gus. my keyboard is acting up

If you have spark at the coil check for spark at the plugs. If there is no spark there then there is an issue there. If there is spark at the plugs then check to make sure you are getting fuel. Its doubtful you would have ruined a new ECM so quickly unless there is a serious electrical issue that you haven't found.

You know the coil is building a charge but are you 100% sure the ICM in the distributor is working? This module runs the whole show - tells the coil to build a spark and sends a pulse signal for the injectors to do their thing. It seems nobody on the internet can agree with what to call any of the related sensors that are accused of creating the error code 15 fault (idle motor position sensor fault). I got TPS, ICM, PCM, CPS, and then side tracked onto IAC's and power transistors. Then I got really stupid posts like - https://www.maxd50scene.com/threads/...ad-distributor :rolleyes:

Ok so I bought a spark tester and after putting the new ecm in and plugging in the tester to the coil wire I got spark during the starter ingaged the first time after tring to start it a few times i tried the tester in the coil wire again and no spark util i release the key back to on.then it sparks one time. there is no spark to the plugs at all. going to look at the ignition switch next

was the starter changed recently? some trucks have a 3 wire starter - 1 wire is for the power to ignition when the key is in the start position.

I second the reply.
Have you tried putting 12 volts to the + side of the coil using a jumper wire from the battery to the dropping resistor. That would bypass the key switch and the starter.

just did a test I found here using an LED light and it seems the ignition control unit is bad. trying to find one. the one in it said J121 but it doesn't come up as one for this engine. is this the correct one and where can i get one fast.

Might be an aftermarket unit. Go onto ebay and do a search. They have a ton of them - just match it by appearance. Hopefully this will be the fix you've been looking for. ICM's going bad is common.

*don't leave your ignition on for extended periods without having the engine running, this will bake an ICM.

The new ICm came in today and no joy. put atest liht on the coil and it's bright when key is on and dims during cranking. put a spark tester on the coill and it sparks once on first turn of key and once when you stop trying to start it. so far new computer, relay, ICM and plug wires. Whats next, coil?

Did you check the starter wiring - still sounds like no power to the ignition when in the start position

I'VE GOT SPARK!!!!!!!! ok this is embaressing but I think i might have had the plug for the distributor on backwards. Giong to start a new thread cuz I got no start yet so its plugs or fuel.

SYSTEM TEST

Check for spark at the spark plugs. Refer to the spark test.

Check all wiring and plastic connectors for tight and proper attachment.

With an ohmmeter, check between the positive (+) and negative (-) primary terminals of the ignition coil. The resistance (cold) should be 1.3–1.7 ohms. Between the (+) primary terminal and the high tension terminal, the resistance (cold) should be 12–16 kilo ohms. The insulation resistance between the (+) primary terminal and the ignition coil case should be infinite.

The resistor wire (brown and yellow) resistance should be 1.2 ohms (cold). To measure, separate the plastic connector at the igniter and attach one wire of the ohmmeter to the yellow wire and one to the brown.

Remove the distributor cap and ignition rotor. Check the air gap between the timing rotor spoke and the pick-up coil. When aligned, the air gap should be 0.008–0.016 inches (0.203–0.406mm). You will probably have to bump the engine around with the starter to line up the timing rotor. Unplug the distributor connector at the distributor. Connect one wire of the ohmmeter to the white wire, and one wire to the pink wire. The resistance of the signal generator should be 130–190 ohms.

Checking the igniter last, connect the (-) voltmeter wire to the (-) ignition coil primary terminal, and the (+) voltmeter wire to the yellow resistor wire. With the ignition switch turned to ON the voltage should measure 12 volts. Check the voltage between the (-) ignition coil primary terminal and the yellow resistor wire again, but this time use the ohmmeter as resistance. Using the igniter end of the distributor connector, connect the positive (+) ohmmeter wire to the pink distributor wire, and the negative (-) ohmmeter wire to the white wire.

WARNING
Do not intermix the (+) and (-) terminals of the ohmmeter.

Select either the 1 ohm; or 10 ohm; range of the ohmmeter. With the voltmeter connected as in Step 6, and the ignition switch turned to ON, the voltage should measure nearly zero.

This test is a general test to give you some help to wittle down the issue. Wire color or ohms may be a little different.

I will try to post some test to perform. I had a similar issue years ago and did some research on weak spark starts with our trucks. Use to tick me off that it wasn't getting a full 12 volts during the cranking time. I started removing tape on starter wiring and found the 3rd starter wire I taped up years ago. For the 2 wire starter to work correctly on a 3 wire starter system, I had to put in a resistor inline to the third wire and I also removed the ballast resistor for an additional coil upgrade.

Attachment 19984