Black Beauty has fuel pump electrical issues

[Greg 85]

Well, i couldn't pull codes, I tried.  However I went through the schematic and tested everything. Preformed a full tune up, plugs, wires, cap, rotor, coil and TFI. Ran better but still shutting down after running 45 mins. Smoking real bad from the back of the engine. I think that is the pvc. Idles at 1200rpm and wen it shuts down the throttle feels like you are floating valves and no power, then dies. I think this is a candidate for a carb swap and mechanical ignition!

[Gary Lewis]

Greg - This is obviously your call.  But why can't you pull codes?  If you could you might be able to save the EFI system.  And it is a pretty good system.  For proof of that just look at the horsepower and torque specs for the carb'd 302 vs the EFI'd 302.

However, if you are sure you want to swap from EFI to a carb we can start listing all the parts you will need.

[Greg 85]

Gary Lewis wrote

Greg - This is obviously your call.  But why can't you pull codes?  If you could you might be able to save the EFI system.  And it is a pretty good system.  For proof of that just look at the horsepower and torque specs for the carb'd 302 vs the EFI'd 302.

However, if you are sure you want to swap from EFI to a carb we can start listing all the parts you will need.

I am going to install a new pick up in the distributor  tomorrow,  its the only thing left that I can think of.  Something is breaking down when it gets hot. TFI and coul is new, pick up is the only thing left. Right? Short of the ecm/pcm. I had just about my fill with this truck. I have over 5 invested, had it two years  and maybe have 200 miles on it.

[Gary Lewis]

Yes, a pickup in the dizzy can do it.

But, two years and 200 miles - I see why you are frustrated.  

On the other hand, you have to be CLOSE!  Everything is new.

[ArdWrknTrk]

Unfortunately, as many of us know, "new" doesn't necessarily mean "good"

But it's exceedingly rare.

[grumpin]

Greg, I don’t remember, did you check your coil?

[ArdWrknTrk]

Greg, I'm going to ask if you've checked the FPR?
Do you have (see or smell) any fuel in the vacuum hose?

1200 rpm. idle doesn't sound like no fuel pressure.
It also doesn't seem like it could be caused by a failing ignition component.

Seems more like a flakey IAC.
But I haven't got my hands on the truck.

Maybe the computer is damaged?
Have you inspected the board for scorches or leaking Caps?

[Greg 85]

Tune up, new distributor, coil ,tri plugs and wires.  Problem still exist.  But after hours of searching found out pin #22 supplies ground to the fuel pump relay isn't intermittently. When it messes up, I supplied an exturnal ground and then it started working.  Messed up again checked pin22 on the ecm and no ground, added ground and it started working.  .i say the ecm has gone bad, what says you?

[ArdWrknTrk]

Check the ECM ground that attaches to the battery negative terminal before you condemn the computer.

[Greg 85]

ArdWrknTrk wrote

Check the ECM ground that attaches to the battery negative terminal before you condemn the computer.

I had already added another ground for the ecm as well as all the grounds from battery, chassis, engine and body, cleaned the rest. All mew grounds under the hood with new power cables and solenoid. I plan to pull the ecm tomorrow and crack it open to see if I can see anything burnt up.

[Greg 85]

ArdWrknTrk wrote

Greg, I'm going to ask if you've checked the FPR?
Do you have (see or smell) any fuel in the vacuum hose?

1200 rpm. idle doesn't sound like no fuel pressure.
It also doesn't seem like it could be caused by a failing ignition component.

Seems more like a flakey IAC.
But I haven't got my hands on the truck.

Maybe the computer is damaged?
Have you inspected the board for scorches or leaking Caps?

IAC is new ad well as just about every electrical part on the truck.😂😂😂

[ArdWrknTrk]

Have you considered an exorcism?  

[Greg 85]

ArdWrknTrk wrote

Have you considered an exorcism?  

It has been a nightmare that seems, looking back, to have stemmed from the electrical searching for ground, having poor grounds and overheated grounds caused alot of issues in different systems.once I got the grounds fixed next was all the individual issues causef by poor ground and believe that the ecm went with or along with everything else. But today I was able to prove the issue for the first time an seen the results and they are good!😁I think I see a light at the end of the tunnel!

[Gary Lewis]

Excellent!

When/if you decide it is time for a new ECM, let's find the right part number.  And the easiest way to do that is if you have a sticker, usually on the passenger's side valve cover, that gives the calibration code.  If not, we can usually figure it out.

And, if you are pulling the ECM it should have info on it that will help.  But, it is likely that several different ECM's were used.

[Greg 85]

Gary Lewis wrote

Excellent!

When/if you decide it is time for a new ECM, let's find the right part number.  And the easiest way to do that is if you have a sticker, usually on the passenger's side valve cover, that gives the calibration code.  If not, we can usually figure it out.

And, if you are pulling the ECM it should have info on it that will help.  But, it is likely that several different ECM's were used.

I have pulled the ECM, and between the ECM #'s, calibration code and VIN I was able to order one through my local parts house. Side note Pin #22 the problem child came out with the plug along with 5 other pins out of the ECM. Defiantly could be the reason I was having so many different issues. Is this common for pins to break loose from the ECM and be stuck in the plug? I should have my ECM in a few days and I still need to fish out the broken pins from the plug but hope and pray that this is the final piece to the puzzle. I am also going to pull the IC and replace all the bulbs for the warning lights as I think that is why I could not get flash codes. I feel this is near the end of the saga that is Black Beauty electrical nightmare! 

[Gary Lewis]

Sure glad you were able to find one.  Just getting the number is sometimes difficult, but finding a replacement has proven hard for some.

I don't think it is common for the pins to break loose.  I have several ECMs and none of the pins were loose when I pulled them.

But I do think this has to be a big part of your problem.  Let's hope it solves all of them.  

[71_badmach]

Hello,

I was browsing the thread and hope you resolved the issue with the ECM.  I thought it was amazing that you could order a replacement for a 35 year old truck.  

BTW, I also have an 85 with the EFI, and was considering going back to a carb setup.  My issue was ignition problems, and some strange electrical issues.  

Dave

[Greg 85]

71_badmach wrote

Hello,

I was browsing the thread and hope you resolved the issue with the ECM.  I thought it was amazing that you could order a replacement for a 35 year old truck.  

BTW, I also have an 85 with the EFI, and was considering going back to a carb setup.  My issue was ignition problems, and some strange electrical issues.  

Dave

The problem still exist. However I know what is happening now, just don't know why.

[Greg 85]

Gary Lewis wrote

Sure glad you were able to find one.  Just getting the number is sometimes difficult, but finding a replacement has proven hard for some.

I don't think it is common for the pins to break loose.  I have several ECMs and none of the pins were loose when I pulled them.

But I do think this has to be a big part of your problem.  Let's hope it solves all of them.  

Okay, so still did not fix the issue with loosing ground although the length of time has lengthened before it loses ground. Okay so I know it is losing ground at the fuel pump shut off relay. When it loses it I can add an external ground and the truck will start right up, remove the ground and sometimes it will stay running other times it'll die. Any thoughts?

[Greg 85]

Gary Lewis wrote

That's a bit more complex, but not too bad.

I'd start through the system inch by inch, starting at the tank selector valve/switch.  If that doesn't work you won't get voltage to the pump.  And they are a known problem.

Gary, is it possible to get pages 60 and 62 for the YY and ZZ wires for the fuel pump cutoff relay on both 85 and 86 years?