No spark, No fuel 1990 5.7 TBI

[Shannon76]

Hello all and thanks in advance for allowing me on the forum. I am trying to help an elderly widowed lady with her late husbands farm truck and I have hit a brick wall. The truck is all factory with only 28,000 miles.
It's a 1990 C1500. It does not have any spark or fuel when spinning over. It sits a lot and my first thought was that a rodent had chewed a wire into but I have not found any wiring issues so far. Here is a run down of what I have done or confirmed to this point.
1) battery is fully charged and engine is turning over quickly
2) no spark at plug or distributor coil using plug test light
3) no fuel spray in intake when turning over
4) noticed check engine light stayed on with key switch turned on
5) did the A,B jumper at diagnostic port and the only code I got was 12 but the check engine light went out and has since stayed out.
6) I have confirmed there is gas in the fuel tank and I can here the fuel pump cycle when the key switch is turned on.
7) I have not actually checked fuel delivery or pressure to the throttle body at this point. I do not have a gauge and aside from cracking a line open and watching for spray when the switch is turned on (which I don't want to do for safety reasons) I can't think of another way to check supply. I would appreciate any suggestions!!
8) I have replaced the ignition control module, distributor cap, rotor button and ignition coil
9) I have verified power on the 10Ga pink wire at the ignition coil and power on the small pink wire at the ignition coil while the key was both in the run and start positions.
10) When inspecting the distributor it was very corroded inside and the rotary button was a pain to get off. I cleaned it up fairly well and tried testing the pick up coil with an ohm meter with the only test procedures I could find online which were
a) confirmed there was no short from either wire to the body of the distributor
b) checked resistance through the pick up coil by taking a reading across both wire ends. The reading was around 780 ohms. I have read that anything from 500 to 1500 is acceptable. ????

I am going to go ahead and install a new distributor assembly with new pick up coil since this one was so corroded and rusty but I have a feeling that is not going to fix it. Is there anything here that confirms the ECM is good or bad and is there anything I am overlooking. Any way I can test the ECM?? At this point I would have been better off to take it to a shop for her but now it has become personal and I am determined to figure this out. I have seen a lot of top notch feedback from Jims86 and other guys on this subject and I'm hoping y'all can help me get her running. Any help is greatly appreciated!!

 

[74 Shortbed]

Welcome to the site..

 

[1987 GMC Jimmy]

We need to see what's going on with that SES light before proceeding. It should do a self-test when you first turn the key to ON. If it's not even coming on then, I'd check your ECM A and B fuses. If those are good, I'd move to the bulb being burnt. If it's not burnt, it's safe to suspect an ECM problem. I've unplugged the computer to test the bulb on my Caprice before if you don't want to dig around behind the cluster. If you end up getting your SES diagnostic circuit back without replacing, I'd actually take the ignition control module out and have it tested. One word of advice on that... Don't buy Duralast, MasterPro, etc. ignition parts. Always stick to Delco and Delphi when available. I've had good results with the BWD line of parts from O'Reilly's and Advanced, but I'd stick with OEM replacement unless it's an emergency.

 

[Shannon76]

Welcome to the site..

Thanks 74 Shortbed. There is a ton of knowledge and experience on this site and I look forward to learning from it!

 

[Shannon76]

We need to see what's going on with that SES light before proceeding. It should do a self-test when you first turn the key to ON. If it's not even coming on then, I'd check your ECM A and B fuses. If those are good, I'd move to the bulb being burnt. If it's not burnt, it's safe to suspect an ECM problem. I've unplugged the computer to test the bulb on my Caprice before if you don't want to dig around behind the cluster. If you end up getting your SES diagnostic circuit back without replacing, I'd actually take the ignition control module out and have it tested. One word of advice on that... Don't buy Duralast, MasterPro, etc. ignition parts. Always stick to Delco and Delphi when available. I've had good results with the BWD line of parts from O'Reilly's and Advanced, but I'd stick with OEM replacement unless it's an emergency.

Thanks for the input. Unless I am missing something I think the SES light is working properly. As stated above in point 4 and 5 above, I did the diagnostic test using the A,B jumper and the only code I got from it was 12. Prior to this test the Check Engine light was on but after the test it was off and has not come back on so far. (I let it flash the 12 code about a dozen times just to be sure nothing else would come up. I know it is supposed to flash each code 3 times then roll to the next code if there are any others.) All of the parts I have used so far are NAPA brand, as that is the only good local source I have.

 

[Cuba]

Thanks for the input. Unless I am missing something I think the SES light is working properly. As stated above in point 4 and 5 above, I did the diagnostic test using the A,B jumper and the only code I got from it was 12. Prior to this test the Check Engine light was on but after the test it was off and has not come back on so far. (I let it flash the 12 code about a dozen times just to be sure nothing else would come up. I know it is supposed to flash each code 3 times then roll to the next code if there are any others.) All of the parts I have used so far are NAPA brand, as that is the only good local source I have.

The fact you say it doesn't come on anymore is somewhat telling. The SES light should stay on while key is on, unless there's no communication with ECM. That's why 87 GMC Jimmy asks.

 

[1987 GMC Jimmy]

Yep, your fifth point is why I mentioned the SES light. You said it went out and stayed out. Just to clarify, were you talking about the hard code going away, or were you saying it won't come on at all now?

 

[4WDKC]

Had a truck do the same thing.. disconnect TPS and crank

 

[Shannon76]

Ok, now I feel like the village idiot! Somehow I was thinking that there is both a check engine light and a service engine soon light on this dash. Wrong! I had to go over the dash cluster with a flashlight just to convince myself that there is not an indicator on the panel labeled check engine. I think that is where I confused myself and everyone else. I went ahead and performed the diagnostic test all over again. So here is what I should have said previously...
-The SES light comes on when ignition is turned on
-A to B diagnostic test is only showing code 12 when test is performed
-After the test, with the jumper removed, the SES light comes on and stays on when the ignition switch is turned to on.

Again, I am terribly sorry for the confusion I caused and I really appreciate the help. I guess I was just in a hurry and goofed with the indicator light thing.

 

[Shannon76]

Had a truck do the same thing.. disconnect TPS and crank

Thanks 4WDKC. I just went out and tried disconnecting the TPS with no luck.

 

[4WDKC]

It happens no big deal. No spark, fuel spray makes me think its the pick up coil in the dist. The one in my 87 was rusty as hell before it died, it wont tell the ecm when to fire the the coil or injectors. Let us know what happens with the new dist.

 

[Shannon76]

It happens no big deal. No spark, fuel spray makes me think its the pick up coil in the dist. The one in my 87 was rusty as hell before it died, it wont tell the ecm when to fire the the coil or injectors. Let us know what happens with the new dist.

I will keep you guys posted. I got a new distributor in today but it was the wrong one. New one is supposed to be here in the morning. Hoping it is the pick up coil as well. I'm at a lose otherwise. Thanks!

 

[4WDKC]

check the ECM A and B fuses just for good measure

 

[1987 GMC Jimmy]

Ok, now I feel like the village idiot! Somehow I was thinking that there is both a check engine light and a service engine soon light on this dash. Wrong! I had to go over the dash cluster with a flashlight just to convince myself that there is not an indicator on the panel labeled check engine. I think that is where I confused myself and everyone else. I went ahead and performed the diagnostic test all over again. So here is what I should have said previously...
-The SES light comes on when ignition is turned on
-A to B diagnostic test is only showing code 12 when test is performed
-After the test, with the jumper removed, the SES light comes on and stays on when the ignition switch is turned to on.

Again, I am terribly sorry for the confusion I caused and I really appreciate the help. I guess I was just in a hurry and goofed with the indicator light thing.

That's good! The new distributor will definitely answer concerns about the ICM and pickup coil. The rust in there makes me think that it's a good idea to just get a whole new one, anyways. At this point, your ECM is looking fine. I've dealt with many early ECM failures, and I've found that the SES light will either never illuminate or be constantly illuminated in most or all of those cases.

 

[Shannon76]

That's good! The new distributor will definitely answer concerns about the ICM and pickup coil. The rust in there makes me think that it's a good idea to just get a whole new one, anyways. At this point, your ECM is looking fine. I've dealt with many early ECM failures, and I've found that the SES light will either never illuminate or be constantly illuminated in most or all of those cases.

Thanks Jimmy! Some confirmation on the ECM most likely being good makes me feel a lot better. Anxious to get the new distributor installed. The one I received in today had a vacuum advance on it.