Ωhm

Check Engine Light (CEL).

I wonder if someone was chained to it. Any numbers on the block, if so, FBI may want to know.

Found this thread, could/might help. https://comancheclub.com/topic/51644-ecuecm/

Probably too late for a photo. But for myself, lesson learned here.

Let me try and make a fool of myself here. Difference in ohms determines current flow. Current flow through INJ coil determines magnetic strength. Magnetic strength determines the UP/DOWN, ON/OFF for the slug within the INJ. I do believe that the INJ must be a match set with the INJ driver mounted on the ECU. Remember I can justify anything to myself. Assumption: Different INJs solve your problem.

Oil Pressure Gauge has nothing to do with C101, but the Coolant Temperature Gauge/Bulb does.

Cluster swap should have no affect on charging voltage. Check the condition of Fuse Link A (BLUE) at the starter relay stud.

Vanilla Black Cow or Boston Cooler?

If they're reimbursed for the repairs, I'd stay away.

Measure Starter Relay coil in ohms and divide that number into Battery/Applied Voltage or I=V/R.

Fuel Pump Relay (Bosch cube) coil draw = ≈160mA

When LOGGED-IN. Go to upper right hand corner of screen. Click on Username. Click on Account Settings. Find and click on Signature. Add your vehicle information here (YR, ENG, TRANS, etc, etc) then click on SAVE. This helps everyone. This information will be available every time you post.

Using a voltmeter or 12vdc testlight (preferred) check for B+ on the following pins (use battery negative terminal for ground): D1_5: B+ (Hot at all times) D2_4: B+ (Hot during KEY ON/CRANKING). D1_6: KEY ON (B+ (Hot for 2-3 seconds)) or CRANKING (B+ (Hot during CRANK)).

Check that hose for the Fuel Pump Pressure Regulator for fuel. Sure is close enough.

Been a long time and don't think I could ever find the two that I had. But the best one of the two was the one that someone made in metal shop (high school). Somewhat involved but kind of a simple project, if you got access to the machine tools on hand.

Myself, I'd deal with @cruiser54. Wouldn't want no metal filings in my intake manifold unless you remove and steam clean it.

Welcome to the CC forum.

Hot going to the Fuel Pump Relay is RED. The Fuel Pump circuit itself is ORANGE (ORN). Things that splice off of this circuit may have a tracer. FYI MJ_1987_Electrical_Manual_1.pdf

Okay thanks. I'll forget LOW/HIGH. RED usually means BATTERY FEED (Hot at all times).

So its a boneyard golden nugget?

Took a visit to NickInTimeDesign and sure enough "ECU CODES". No listing for "Fuel Pump Relay", but that could be just Website needs updating. Arrow down might mean LOW whereas arrow up might mean HIGH. Thank for opening up these new headaches for me. When you say "bypassed the relay" do you mean that there's a jumper wire in place of the relay? Also found this under RENIX PARTS SUGGESTION: Intake Manifold Air Temp Sensor (IAT) The stock IAT sensor has been long discontinued so we will need to adapt a similar sensor instead. – GM part 213-190 will replace it but requires the intake manifold port to be retapped to 3/8″NPT (stock is 1/4″NPT) and replacing the pigtail connector as well. This will update the sensor to a currently used part with the correct resistance range. @eaglescout526 Is this true, no NOS IAT sensors? @PhilisDiller 1987 MJ 4x4 Shortbed 4.0 5 speed manual

ECU code; interesting. I noticed a down arrow next to the word relay. Are there more ECU codes under that?

I don't get REM "throwing a code". Keep this high on your list. Yes it would be.

1969 Boss 429 Shotgun

Been thinking, you may not be able to hold proper intake manifold VAC if the EGR valve is unseated (leaking) somehow.