Tarheel Blue Posted February 11, 2022 Share Posted February 11, 2022 I was hoping that with this post I would be able to tie up the dangling posts that I have out there; ISO Styleside SWB w/ Dual Tank owners '95 FDM for your '85 gauge Definitive way to wire an electric fuel pump for a Pre EFI Bullnose Unfortunately, I’m in need of some more help. The Good - I have installed a 33gal Bronco tank into my truck along with a new FDM from a ‘95 Bronco, all new nylon lines/ fittings, a Holley FPR. The sender modification seems to be working just as I’d hoped as the gauge reads correctly. I was able to adjust the fuel pressure to 5psi to work with my YFA and there are no leaks. So far so good, right? The Bad - went to start it up for the first time and again, everything seemed to be working and satisfying my goals ( very fast prime of the fuel bowl resulting in extremely short crank before ignition) However, it will not idle. I can keep it running by feathering the pedal, but the moment that I let off the gas, she dies immediately. I can hear the electric pump quit one second after the engine dies, so I’m assuming that it’s supplying gas the whole time it’s running. The Ugly - I’m at a complete loss as to where to go looking for the problem. Link to comment Share on other sites More sharing options...
Gary Lewis Posted February 11, 2022 Share Posted February 11, 2022 Two things. First, on the Youtube there are two issues with the way you posted it. The first is that you got a link to it and not the embed code. You hit Share and then Embed and get that code. And, you then paste the code between the > and < of the code Nabble puts in when you click Embed. As for the stalling at idle, my first thought was that you still have too much fuel pressure. And while that is possible the way it dies in the video is immediate, as if you turned the key off. Not laboring, which is what I'd expect if the carb was flooding. How easily does it start after it dies at idle? Is there any chance the idle stop screw or idle solenoid was changed while the work was being done? Maybe you could turn the idle stop screw up a bit and see if it will run there? Link to comment Share on other sites More sharing options...
Tarheel Blue Posted February 11, 2022 Author Share Posted February 11, 2022 Two things. First, on the Youtube there are two issues with the way you posted it. The first is that you got a link to it and not the embed code. You hit Share and then Embed and get that code. And, you then paste the code between the > and I’ll try to do better on the next video It starts back up immediately, every time, just like I was hoping it would. I have tried to raise the idle screw on the linkage with no benefit. If I slowly lift off of the pedal, it seems to want to die around 1500 rpm. Link to comment Share on other sites More sharing options...
Gary Lewis Posted February 11, 2022 Share Posted February 11, 2022 I’ll try to do better on the next video It starts back up immediately, every time, just like I was hoping it would. I have tried to raise the idle screw on the linkage with no benefit. If I slowly lift off of the pedal, it seems to want to die around 1500 rpm. As you slowly release the pedal does it die instantly like it does in the video? If so I'd say that you either have an electrical problem where the ignition is shutting off, or the idle circuit is plugged in the carb. Is the engine warm when this happens? Maybe there's some issue with the choke being on too much or completely off? And have you tried opening up the idle mixture screw? Write down where it is before you change it, but I'd open it up a couple of turns to see if that makes a difference. Maybe it is way too lean? Link to comment Share on other sites More sharing options...
mat in tn Posted February 11, 2022 Share Posted February 11, 2022 As you slowly release the pedal does it die instantly like it does in the video? If so I'd say that you either have an electrical problem where the ignition is shutting off, or the idle circuit is plugged in the carb. Is the engine warm when this happens? Maybe there's some issue with the choke being on too much or completely off? And have you tried opening up the idle mixture screw? Write down where it is before you change it, but I'd open it up a couple of turns to see if that makes a difference. Maybe it is way too lean? any chance of a vacuum leak? Link to comment Share on other sites More sharing options...
Gary Lewis Posted February 11, 2022 Share Posted February 11, 2022 any chance of a vacuum leak? Good thought, Matt. A huge leak, like the brake booster hose left off, might do that. Link to comment Share on other sites More sharing options...
Tarheel Blue Posted February 11, 2022 Author Share Posted February 11, 2022 As you slowly release the pedal does it die instantly like it does in the video? If so I'd say that you either have an electrical problem where the ignition is shutting off, or the idle circuit is plugged in the carb. Is the engine warm when this happens? Maybe there's some issue with the choke being on too much or completely off? And have you tried opening up the idle mixture screw? Write down where it is before you change it, but I'd open it up a couple of turns to see if that makes a difference. Maybe it is way too lean? I wouldn’t say it dies instantly, but around 1500 it really starts running rough. If I want it to stay running, give the pedal a tap and it smooths back out, but it’s now around 2000. I don’t think it’s an electrical issue, but the idle mixture sounds like a good possibility. Ill play with that a bit and see what happens. Side note, While waiting on parts over the last few months, I would bide my time doing lots of little projects that needed doing. One of which was to rebuild the carb. Perhaps I didn’t do something correctly, however I’ve rebuilt this carb a couple of times over the years and it always was spot on when reinstalling. Engine is always cold and feel pretty good about where the choke is. Been in the 60s here and choke has maybe a 1/4” opening prior to start. Your previous thought about not enough pressure is sort of similar to a thought that I have, not enough flow. I just can’t think of an easy way to check the current flow rate. Link to comment Share on other sites More sharing options...
mat in tn Posted February 11, 2022 Share Posted February 11, 2022 Good thought, Matt. A huge leak, like the brake booster hose left off, might do that. it is so easy to find a bad hose, loose fit, broken cap etc. while not even noticing that you disturbed it when working on old trucks. i see so many brake booster vac hoses with the clamp two to three inches up un the hose because the last person missed it or didn't bother to clamp it. this type thing can be anywhere the last person worked. look in all the hard to reach /see places. also check that the carb has no "play" within it. Link to comment Share on other sites More sharing options...
Tarheel Blue Posted February 11, 2022 Author Share Posted February 11, 2022 it is so easy to find a bad hose, loose fit, broken cap etc. while not even noticing that you disturbed it when working on old trucks. i see so many brake booster vac hoses with the clamp two to three inches up un the hose because the last person missed it or didn't bother to clamp it. this type thing can be anywhere the last person worked. look in all the hard to reach /see places. also check that the carb has no "play" within it. Thanks Mat, and you’re absolutely right about misc hoses leaking. That is one of the other “side projects” that I did when waiting for parts. I replaced ALL of my hoses, found a couple of devices (EGR, PCV, etc. ) that needed replacing and made sure that my EVAC system was back to working properly. Hold that thought . . . When Gary and I were musing possible fuel issues it occurred to me, an engine needs the correct balance of fuel AND air. If I’m fairly confident that I don’t have a fuel issue, perhaps I have an air issue. Even though I thought that I was being very thorough in checking all of my hose connections, I just found a fairly large port on the main tree that I failed to put a cap on. 3/8” on the bottom/ back of the tree and not detectable at a good glance. I capped it, started her up, still wouldn’t idle, but much less sudden dive towards dying. Adjusted fast idle and idle mixture a bit and .. . She lives!! Link to comment Share on other sites More sharing options...
Gary Lewis Posted February 11, 2022 Share Posted February 11, 2022 Thanks Mat, and you’re absolutely right about misc hoses leaking. That is one of the other “side projects” that I did when waiting for parts. I replaced ALL of my hoses, found a couple of devices (EGR, PCV, etc. ) that needed replacing and made sure that my EVAC system was back to working properly. Hold that thought . . . When Gary and I were musing possible fuel issues it occurred to me, an engine needs the correct balance of fuel AND air. If I’m fairly confident that I don’t have a fuel issue, perhaps I have an air issue. Even though I thought that I was being very thorough in checking all of my hose connections, I just found a fairly large port on the main tree that I failed to put a cap on. 3/8” on the bottom/ back of the tree and not detectable at a good glance. I capped it, started her up, still wouldn’t idle, but much less sudden dive towards dying. Adjusted fast idle and idle mixture a bit and .. . She lives!! Congratulations!!!!! Link to comment Share on other sites More sharing options...
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