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My car stopped running. It cranks but won't start. I get Code 54, indicating a problem with the fuel pump relay.
I'm thinking the fuel pump relay is not the cause and that's what I'm here to find out.
When I initially turn the key to the "run" position I can hear the pump prime and the relay click on and off. If I place a bit of paper towel under the injectors and crank the engine, they get soaked with fuel. So at this point I can't know that it is working at 100% but fuel is getting to the throttle bores. Further, when I release the key after cranking the engine in an attempt to start, I hear the fuel pump run for a second or two and shut off, like normal.
Further, if I hook up the timing light and crank the engine, the light does not flash. So I'm thinking it is a coil, cap, or rotor issue. Haven't dug farther into it, yet.
Can the relay be bad yet the pump still seem to work and can it cause the ignition not to work?
I checked with Tunerpro RT and the sensors look normal, in comparison to "baseline" data logs from the past.
Last edited by charliemccraney; 02-25-2018 at 04:25 PM.
I've had issues with ignition modules in the past. In both instances, neither the injectors, nor the ignition would work. That is also outlined in the how to test the module linked above.
Also in both instances, the car would start when cold but die when it got warm. Now it simply isn't starting.
The current module is 2 years old, and AC Delco.
If the ecm was not getting pulses from the icm, then neither the pump nor injectors would work.
Last edited by charliemccraney; 02-25-2018 at 04:26 PM.
The ign is unrelated to the relay or pump. Sounds like a bad pu coil or icm.
Ignition is VERY related to the fuel pump relay.
If there were no pickup coil signal through the ignition module to the ECM, the relay would not be turned on except during the 2-second "prime" cycle, and the injectors wouldn't spray.
The ignition module could have failed in a way that doesn't affect it transmitting a crank signal to the ECM. Possible, not terribly likely.
Pump runs, injectors spray. Pickup coil and ignition module are communicating with the ECM, which is driving the fuel pump and injectors. Most of the fuel-system wire harness has therefore been verified as "not open". It is possible to have high resistance in the wiring or across the contacts of the fuel pump relay leading to low fuel pressure and poor pump performance...but if the injectors are spraying fuel, that doesn't seem to be a high priority for testing.
"I" would be looking closely at the ignition fuse(s), the ignition coil primary wire connectors, the coil itself, the high-tension coil wire, THE CARBON BUTTON THAT TOUCHES THE ROTOR BLADE, the rotor, distributor cap, plug wires and spark plugs. If NOTHING ELSE is found to have failed, replace the ignition module.
It was the ignition module. I went through the entire trouble shooting procedure in the Helm manual. That upsets me because it was almost exactly 2 years old, AC Delco D1943A, made in USA. The one before that was Chinese and lasted far longer.
I got a replacement D1943A but there is an AC Delco Professional D1906C. It's about twice the price. Any idea if that is actually better?
Test the ignition coil using a spark-tester with a wide spark-gap suitable for HEI, and also an ohmmeter.
The "usual" reason that ignition modules fail is that the ignition coil has internally shorted, leading to excess current draw through the module.
Because the coil operates at high voltage--and an ohmmeter operates at very low voltage--there is no guaranteed test of an ignition coil except to verify that the windings are reasonably close to "spec" AND it throws a powerful spark.
I haven't seen a "Made in USA" ignition module in many, many years. Far as I know, Delco outsourced to Singapore decade(s) ago.
WILD GUESS WITH NO EVIDENCE: The D1943A and the D1906C are exactly the same except for the warranty offered. You could also toss in a D1984A. Amazon sez that all three fit my '88 K1500.
SOMEWHERE there's an 8-pin module that looks just like the others, but it's intended for marine applications (No computer timing.) THAT ONE YOU DON'T WANT. [EDIT] That'd be D1965A [/EDIT]
I'll be saving that picture. And good info Schurkey. I learn so much hanging out here. Wish you guys were closer so I could buy you a beverage of your choice.
I did check the coil with an ohmmeter and it checks out ok.
Checking with a spark tester is a part of the trouble shooting procedure but of course, it wasn't working.
The box for the Module has Made in USA on it.
Warranty between the pro and standard modules is the same.
Two minor problems with this diagram and specs. Both involve Test #2.
A. "0" ohms is not acceptable--years ago (1994, for example) Delco used to say that you'd use the low-ohms scale of your ohmmeter, and the results should be "zero or nearly zero". And that's fine if you have an antique ohmmeter where the low-ohms scale doesn't provide top-notch resolution. For any modern (highly accurate) digital meter, "about half-an-ohm" is a reasonable guide. 0.4--0.7 wouldn't raise any eyebrows around here--IF THE COIL THROWS STRONG SPARKS. Note that the ohmmeter may have to be manually "zeroed" because the test leads will probably add 0.2 ohms! (at least, my meter needs to be zeroed.)
B. The arrow for the test point is placed incorrectly. I'm looking at Delco Service Bulletin 1D-183, dated 11-10-94 (page 5, figure 8.) The figure is...well...not very good. Hard to make out--I had to stare at it awhile. Point being, your figure has the test leads connected to the lower two slots. The test leads should be connected to a lower and an upper slot, either lower, either upper will be fine. Connected to a lower and an upper slot, you'll measure the primary winding, and we'd expect--as said above--about half-an-ohm.
Put another way--the "left" connection for Test 2 could go to the same "B" slot that the connection for Test 1 goes to, instead of the "A" slot. Leave the "right" connection as illustrated.
I did check the coil with an ohmmeter and it checks out ok.
Retest using updated Test 2 test points.
Originally Posted by charliemccraney
Checking with a spark tester is a part of the trouble shooting procedure but of course, it wasn't working.
Retest with spark tester. Use one for HEI, not points or Chrysler electronic ignition. Some are adjustable, see their instructions for a suitable gap.
My favorite spark testers look like a spark plug that someone welded an alligator clip to--but they're different on the firing end. The HEI style has a recessed center electrode that makes the spark jump even farther.
Originally Posted by charliemccraney
The box for the Module has Made in USA on it.
Warranty between the pro and standard modules is the same.
I did a quick internet search and found nothing. A more extensive search might turn something up. (That's why I gave the bulletin number and date.)
I'm not in a position to scan and host a copy...yet. I've scanned 'n' hosted sections of other Delco bulletins, though. I need to clear a giant heaping pile of other stuff off my List Of Things To Do before I will have time to fire-up the scanner.
I'll call the test outlined in the bulletin test 4. I used pigtails in which each wire is measures about .3 ohms on my meter.
Test 1: Infinite
Test 2: .4 ohms
Test 3: 8.99 kohms
Test 4: .8 ohms at each
Test 2 result doesn't make much sense given that each wire is .3 ohms. Maybe it's just in the margin of error of my cheap meter. Another coil indicated similar results.
02-25-2018, 03:22 PM
