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Change fuel pump...engine now stalls at low RPM

n36511

Regular Contributor
So I was able to switch out my fuel pump with a new one on my Crusader 454xl . I switched it out because the old one was leaking fuel. Worked fine, was just leaking fuel. After switching it out, the engine will fire right up, however it dies if I do not move the RPM above 1100. As soon as I back off the throttle and it drops below 1100 rpm or so, the engine dies. If I am watching closely, I can pump the throttle and it comes back to life. I do not see any black smoke that I can tell. Is it possible that I got somehting in the line somewhere and it is blocking fuel flow? Would that not also be evidient at high rpm? This is not under load as I cannot put it in gear or it dies. Any thoughts of where to start? Change fuel water sep (it is the next filter in line)?

Thanks for the help,
Scott
 
May have figured it out...... maybe... Looking at the parts diagram it appears I ordered a fuel pump for a carbureted model and there is a specific pump for the TBI model.....not sure if that matters and everything hooked up fine, but the parts are def different. I will bolt the old one back on to see if the stalling issue goes away. That on still has a fuel leak but worked fine before I replaced it. If it does work, epic waste of time and $300.
 
Don't beat yourself up too bad Scott, we've all had to pay tuition to learn something! The TBI system uses 5-6 psi as the NA uses 3-4 in most cases. Where was your original pump leaking from? I have had them just quite or fail to pump, but never leak. My leaks have alway been in the fittings.
 
Don't beat yourself up too bad Scott, we've all had to pay tuition to learn something! The TBI system uses 5-6 psi as the NA uses 3-4 in most cases. Where was your original pump leaking from? I have had them just quite or fail to pump, but never leak. My leaks have alway been in the fittings.

Thanks :)
. It appeared to be leaking where the wiring entered the pump....however it was in a tight place and I was not able to confirm 100%. I kept the old pump and will return to the boat and redo the fittings and install the old one to see if that clears things up.
 
the GM TBI's from the mid 90's are set up to run on 5-6X the fuel pressure that a carburetor wants to see...

They don't come with a "pressure test port" which makes basic troubleshooting a PITA...even adding the GM adapter isn't always easy...
 
So I put the old pump back on and all operations returned to normal...no issues at idle! Happy about that!! However, I did confirm that the leak is coming from the pump itself and not the fittings. It is leakiing out around where the wiring harness enters the pump. Time to order one. Those things are expensive!! Especially when you order the wrong one first :mad:
 
Interesting Scott, I've near seen one leak like that. But overall, now your a PRO at replaceing the pump and you have all the tools!:)
 
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