Geared

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.

What should I check?...could it be a fuse? Any ideas would be great

djfury05

I wouldn't think it'd be a fuse since you had multiple readings from the aem gauge. If your not getting the pump to prime I'd pull the fender well out and check the voltage at the pump. If it's 12v + then the pump is probably bad.

Are you using the Racetronix harness?

Geared

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

djfury05

I see your running the stock harness from the top of the pump to the boost a pump hotwire. That's a restriction that you should upgrade; the drivers tank needs to be dropped to install a new harness.

If you haven't already measure the volts at the pump and report back.

Geared

well oddly enough, I got to the car this AM (left the car in the parking lot last night)....

turned on accessory mode - fuel pressure said 70 - and she fired right up.

So odd....

Now I try to track down the gremlin....fun stuff.

saplumr

That's almost text book fuel pump relay failure symptom. Won't start when hot but does after cooling down.

Geared

Hmm ok....What would cause that? Age? BC the miles are super low.

saplumr

Do you have a racetronix harness connected directly from the alternator to your BAP or is it feeding from the fuseblock?

Geared

see post #3

Geared

bump

saplumr

Check your fuel pump relay for burn marks and maybe buy another one just to check the next time your symptoms occur. I had a issue and my fuel pump relay was overloaded and eventually took out that fuse block section. If you have a fuel pressure gauge it will tell you if you have power to the pump when accessory is on. Look at it when your problem occurs.

Ultrasport05

I had my fuel pump relay get fried from the boost a pump. The car would randomly die on long road trips. The boost a pump fried the 20amp fuse and damaged the relay. I replaced the relay, fuse, and installed a racetronix harness and haven't had a problem since. Try a new relay and see if it fixes your issue.

I've since completely removed the BAP in favor of an ECS stage 1 fuel system. Never liked the idea of the BAP

Geared

https://www.corvetteforum.com/forums...side-door.html

I *seemed* to notice this at the same time as whats described in the OP was happening...

anyone believe related?

but why would the car all of a sudden have 70 fuel pressure, and fire up the next morning - no jump, or anything. I will have to check tomorrow if the window is still doing that.

could the alarm cause any of this?

i will also attempt to get a multimeter, and do some testing tomorrow as well.

Geared

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.

Any advice?

djfury05

Pull it out and put a 40 amp in.

Geared

could this have harmed anything tho? the boost a pump? what about the relay?

Geared

also, it could have melted bc of external heat (i.e. it is near the motor) but I guess the fuse holder top would have melted too.

djfury05

Probably not. The fuse would prevent the power from even reaching the relay. Boost a pump should be fine.

Did the element inside the fuse burn out or did just the green plastic melt away?

Geared

when i removed the old fuse, sure enough Fuel Pressure in accessory mode went to 6 then 5 and so on to zero.

I put a new 30 amp in there for now (fuel pressure went back to 70 in accessory mode!! great news - although it was 70 - even hit low 80's when i fired her up cold today before fuse replacement...so that old one must have been making intermitten contact???

I ordered a Maxiblade 30 Amp fuse and fuse holder w/ 10 gauge which should come next week.

As to the fuse - melted:

Geared

Why would my fuel pressure be zero (or 3 like it was when I pulled the crapped out fuse), and the car fail to start if the fuse to the boost a pump was blown? Wouldnt my stock fuel pump allow the car to start? Nothing was even priming...

I dont see how that can be right....if the fuse blows, and Im driving I go 0 FP.... lean... kaboom? wtf?

Also...

As I understand it the boost a pump (vortech / ECS) should draw around 15 amps...correct? The fuse was 30...so...How can I check the amps going through that hotwire with a multimeter, safely? Through the fuse holder?...if so how???

Will the amps be different at priming in accessory versus at full boost? This is what could be an issue...

Im going to pull the inner liner and try to see the relay tomorrow...I guess i need to know how to check this too?? damn, I need help lol.