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Is the wiring to the pump heavy enough? Lack of current will make it run hot, then die
I based the wire size on what Holley said the amp draw was and wire charts noting draw and distance. So it should be fine.. it also matched was was provided on my aftermarket fuse block. Not saying that it couldn't be some fluke issue though.
remind me what you did for fuel? if it's a corvette FPR, you're in luck because that's junk and you should replace it with a proper filter/regulator combo.
remind me what you did for fuel? if it's a corvette FPR, you're in luck because that's junk and you should replace it with a proper filter/regulator combo.
The Corvette regulator is NOT junk. When used within its capabilities, it works just fine. Go beyond those parameters, it will not work properly. You must have done that once, or more.
Yesterday I checked a couple items trying to get my car to run right.
1. I swapped a fuel pressure regulator from spare motor over to this one and made no difference.
2. I put in a new crank position sensor. It ran horrific at first then was able to idle ( i assume cause it was a new sensor and needed to learn). While idling it died randomly a few times and you could hear fuel pump turning off and on like it did before. So I would restart and it would run for a while and shut off again. So I would say this did not fix the problem.
I have read the crank sensor needs to be hooked up to a calibration unit of some sort but I don't have that. But I am guessing its ok now since it will rev and idle and the fact I still have the same problem as before.
Camshaft position sensor is next. Hopefully it will pull out without taking manifold off.
The cam sensor is really only for starting to tell the ECM where the cam is in relation to the crank. It will start and run without it, but a lot of cranking is involved until the ECM figures out where the cam is in relation to the crank
The cam sensor is really only for starting to tell the ECM where the cam is in relation to the crank. It will start and run without it, but a lot of cranking is involved until the ECM figures out where the cam is in relation to the crank
Roger that, I guess I don't need to change that then. Back to square one :/
Roger that, I guess I don't need to change that then. Back to square one :/
Hey Billy, how about just trying a different pump? Maybe the internal wire on the pump is loose or something. I don't really know, just throwing stuff out there since you have tried endlessly with different things.
Hey Billy, how about just trying a different pump? Maybe the internal wire on the pump is loose or something. I don't really know, just throwing stuff out there since you have tried endlessly with different things.
Jaime
The reason I don't think its the pump is because I have tested the signal to fuel pump (without pump wired in) and its an interrupted signal straight out of PCM before it even gets to the pump or to the relay that feeds power to pump. So I feel I have something sketchy in the wiring or a bad sensor somehow affecting that :/
I'm trying to troubleshoot so here is an idea regarding my issues....
Would a bad fuel pressure regulator be causing this issue?
When I turn the ignition on the pump turns on and primes... fuel pressure rises right past 50 but then instantly drops once priming is done... then a couple seconds later the pump primes again without me touching key. I tried to see how far it would drop in between and it looks to prime again around 20psi. But I feel it would keep dropping if the pump wasn't already priming again. I didn't see any fuel coming out the vacuum port of the regulator. I even put another regulator on from my spare motor but that regulator made a ton of noise and acted the same way so I put my original back on.
1. Shouldn't my pump be holding pressure after prime?
2. If the regulator was not holding pressure would it trigger the pump to prime again through pcm?
Something is wrong wiring wise. Your system will bleed off pressure, have never seen one that didn't.
The pump should only prime one time. The ECM is waiting for a crank signal to initiate the pump full time. For it to prime twice tells me there is an intermittent, loose, faulty connection somewhere.
Something is wrong wiring wise. Your system will bleed off pressure, have never seen one that didn't.
The pump should only prime one time. The ECM is waiting for a crank signal to initiate the pump full time. For it to prime twice tells me there is an intermittent, loose, faulty connection somewhere.
T,
Thanks for the feedback. Time to lay under dash for a while :/
Either the pin is pushed out, the actual wire itself is bad, or the PCM is going south on that circuit. It sounds to me like a bad wire itself, or pin if it comes off an on. Could be a connection at the PCM. If all that fails you can try another PCM just to see if it corrects the issue.
I am leaning towards your pump or regulator being bad, TomM is right that the fuel pressure will bleed back down but that is usually over hours or days of being turned off, in your words it went from a little over 50 pounds of pressure which is still to low to 20 pounds of pressure almost immediately, that is not right it should not bleed down that fast. Possibly a defective check valve in the fuel pump itself or in the fuel regulator. Another possibility is a stuck open injector or multiple stuck open injectors constantly dumping fuel into a cylinder or cylinders? Possible cause of it running poorly? If that is the cause are you having hard crank issues like a possible hydraulic situation in a cylinder?
I pulled the harness plugs off... removed the zip ties and spent a lot of time under dash looking for any physical signs of trouble in the wiring. No wires were cut, loose, damaged or whatever. No pins on plugs were pulling out. I checked power at the pins on the plugs and also checked grounds. They are all good.
Crank sensor is replaced. I also replaced fuel pressure regulator and it acted no different than the one I removed.
I'm thinking next step is to plug the harness back in, start it up and start shaking the crap out of stuff to see if anything makes it cut out. Anything else I should check BEFORE plugging the harness plugs back in?
This weekend I made myself install the led tail lights I got for Christmas instead of getting nothing done other than the trouble shooting I have been doing on my weird cut -out problem.
I installed the tail lights at first using the socket adapters that it came with but it was doing weird stuff and not working properly so I cut all the socket plugs off and soldered in all the connections and now they are working great
And in other BIG news... I made a call this morning and I think I have the fix to my cut-out issue with the engine on the way!!!! I will post more about that very soon!
04-30-2019, 01:04 PM
. I don't really know, just throwing stuff out there since you have tried endlessly with different things.
