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Went for a drive last night. Nothing special. Didnt even go wot or close to it...
Park the car, eat dinner.
Get to my car after dinner, and it starts, and within 2 seconds stumbles and dies.
No codes, but after she died.... I noticed my aem fuel pressure gauge was at lets say 18 in accessory mode, I tried cranking the car...it cranked but wouldn't fire. Almost sounds like ita not getting fuel. I dont hear the pump prime. After trying to start it a few more times....the aem fuel pressure gauge went 15, 13, 8, 4, then 0 after a few restart tries. Does this mean my fuel pump is shot?
Car has 3,000 miles on it. Has a ecs kit, full bolt on, meth car. Stock fuel pump ( has 3,000) and a boost a pump.
Direct "hotwire" 10 gauge power wire to the boost a pump on a relay so we're not pulling high amps through the stock harness
What should I check?...could it be a fuse? Any ideas would be great
The most simple thing you can do, is stick a voltmeter onto the terminals at the pump connector. Just keep an eye on this.
If you are even less electrically inclined but you know where the fuse is to the pump, these can be handy
http://www.ebay.com/itm/FAULTY-CAR-FUSE-BUDDY-TESTER-30AMP-CIRCUIT-CURRENT-TESTING-FREE-120PC-CAR-FUSE-/201377123745?hash=item2ee3030da1&item=201377123745&vxp=mtr
Still not great as an initial diagnosis, but it would at least see if the pump circuit is drawing current during any non start event.
If no, that would be a clear sign of a problem, or if too much, also a sign of a problem.
Another thing I noticed I wanted to mention - today I went downstairs to see what the FP Gauge said in accessory..heard the fuel pump prime nicely...the gauge said 73, but dropped to 72, 71, 70... in about 10 seconds...i turned it off.
turned back on accessory mode - 69, 68, 67, settling at 65 ..in about 20 seconds....turned off...
went back down a couple hours later - 73 again.
Is that normal?
when driving it shoots around between high 50's and high 70's from what I have seen.
The pump will prime, and most systems will retain some pressure after the pump has stopped running. So whilst a more consistent number would be nicer, what you describe sounds fairly normal.
Although 73psi assuming that is the units you are referring to, does sound a little high
Is it a boost referenced setup ? What regulator ? Or other ?
My old return style setup would prime and within 2 seconds be at zero psi. As long as you are building pressure to your desired base pressure I wouldn't worry about that. However 70 psi is a hell of a base pressure.
Make sure that your fuel filter or something else in the fuel system isn't getting clogged. It could be that when you shut off the system for a while the debris settles but once you turn it back on it sucks it up again.
Ok, well I havent done much, but I did more "looking over" than "digging in"
I did find this...and honestly, believe it could be my problem. (See below) That said, I am not sure if this blew because of size, melted because of heat, or ????
Is there a way to tell?
I believe it is a 30 amp fuse...and I believe this is my "direct hotwire" 10 gauge power wire to the boost a pump on a relay so we're not pulling high amps through the stock harness.
BAP devices will draw a lot of current simply because of what they do.
If the BAP is active for extended periods, insufficient wiring or connectors will heat up....as is the case here.
Ensure all wiring and connectors are up to the job in hand. If that means better quality or larger fuse holders etc, then so be it.
Measure the current draw and IMO ensure any connectors etc can handle at least 50% more that what you are seeing.
Sizing for short duration bursts isnt the same as long duration usage at high currents.
For fuse holders, look into maxiblade fuse holders, they're basically a larger version of the standard blade.
It may be overkill in some cases...but at least it wont melt and leave you broken down.
To add...a lot of blade fuses you'll buy are just ***** too. If you can pull some from an original car from a junkyard or similar, they'll always be better than the chinese stuff most places will sell.
Moving to the larger blade, simply from size alone they'll handle the current better.
But cannot find a maxiblade fuse holder with a 10 gauge lead wire. I found 8 gauge, but not 10.
Also, using a 50 amp fuse wont allow for overloading the boost a pump or potential electrical fire will it? i.e. I didnt know you could just "put in a larger fuse" without creating a safety problem.
The issue may have been simply the spade terminals in the blade holder werent a good connection and they were arcing causing the heat. Either way, that isnt the first person I've seen their fuse holder melt.
IMO small blades just arent up to the job...but many will get away with them for quite some time.
07-01-2015, 12:13 PM
Car Wont Start - Help! 
