# Engine will crank but won’t start unless you spray starter fluid or fuel in it **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** chevrolet, engines\ **Created:** [December 12, 2019, 4:27pm UTC](https://community.cartalk.com/t/engine-will-crank-but-won-t-start-unless-you-spray-starter-fluid-or-fuel-in-it/154538 "2019-12-12T16:27:50Z")\ **Posts on this page:** 18\ **Page:** 2
**Author:** ![db4690](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/db4690/32/2583_2.png) [@db4690](https://community.cartalk.com/u/db4690)\ **Post date:** [December 15, 2019, 6:42pm UTC](https://community.cartalk.com/t/engine-will-crank-but-won-t-start-unless-you-spray-starter-fluid-or-fuel-in-it/154538/22 "2019-12-15T18:42:10Z")
> [@shanonia](#): > > That info isn’t needed if the pump runs and the car starts and runs OK even under high fuel demand. I disagree . . . it’s a free country I’ve worked on vehicles where the fuel pump would energize every single time But the engine wouldn’t start without a blast of ether Once running, it would stay running until you shut it off, could be hours later Yet the fuel pressure gauge would reveal that the fuel pump wasn’t quite up to snuff, a few psi low Once the fuel pump was replaced, all of the problems went away, and the ether was no longer needed If you need to spray ether to start the engine every time, you’ve definitely got a problem It takes more pressure to start an engine, versus keeping it running Like I said, we’re free to disagree ---
**Author:** ![bing](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/bing/32/4619_2.png) [@bing](https://community.cartalk.com/u/bing)\ **Post date:** [December 15, 2019, 7:38pm UTC](https://community.cartalk.com/t/engine-will-crank-but-won-t-start-unless-you-spray-starter-fluid-or-fuel-in-it/154538/23 "2019-12-15T19:38:12Z")
Maybe I misunderstood but it sounded like he energized the test connector for the pump and the car ran normally. ---
**Author:** ![EMILE.N.TABBAL\_160839](https://avatars.discourse-cdn.com/v4/letter/e/ee59a6/32.png) [@EMILE.N.TABBAL\_160839](https://community.cartalk.com/u/EMILE.N.TABBAL_160839)\ **Post date:** [December 15, 2019, 8:15pm UTC](https://community.cartalk.com/t/engine-will-crank-but-won-t-start-unless-you-spray-starter-fluid-or-fuel-in-it/154538/24 "2019-12-15T20:15:31Z")
yes once the car is on it runs perfectly no problem at all not even in idling, even if i turn it off for a few hours it turns back on as if no problem unless its left for over 5 hours or so. ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [December 15, 2019, 8:16pm UTC](https://community.cartalk.com/t/engine-will-crank-but-won-t-start-unless-you-spray-starter-fluid-or-fuel-in-it/154538/25 "2019-12-15T20:16:52Z")
That tells me the anti drain-back valve on the fuel pump is malfunctioning. Tester ---
**Author:** ![db4690](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/db4690/32/2583_2.png) [@db4690](https://community.cartalk.com/u/db4690)\ **Post date:** [December 15, 2019, 8:22pm UTC](https://community.cartalk.com/t/engine-will-crank-but-won-t-start-unless-you-spray-starter-fluid-or-fuel-in-it/154538/26 "2019-12-15T20:22:12Z")
My money is still on the fuel pump assembly If that turns out the be the culprit . . . I highly encourage you to be an entire fuel pump and sending unit assembly. Do NOT buy just the pump, and reuse the old sending unit and sock. You might regret that ---
**Author:** ![EMILE.N.TABBAL\_160839](https://avatars.discourse-cdn.com/v4/letter/e/ee59a6/32.png) [@EMILE.N.TABBAL\_160839](https://community.cartalk.com/u/EMILE.N.TABBAL_160839)\ **Post date:** [December 15, 2019, 8:24pm UTC](https://community.cartalk.com/t/engine-will-crank-but-won-t-start-unless-you-spray-starter-fluid-or-fuel-in-it/154538/27 "2019-12-15T20:24:52Z")
i already bought a full fuel pump assembly a few month back just incase. i will try a new relay tomorrow if that doesn’t fix it then in goes the new assembly. ---
**Author:** ![db4690](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/db4690/32/2583_2.png) [@db4690](https://community.cartalk.com/u/db4690)\ **Post date:** [December 15, 2019, 11:20pm UTC](https://community.cartalk.com/t/engine-will-crank-but-won-t-start-unless-you-spray-starter-fluid-or-fuel-in-it/154538/28 "2019-12-15T23:20:04Z")
Removing a fuel tank on an S-10 Blazer is actually quite difficult, versus a Silverado of same vintage, and that’s if you’re using a hoist. Can’t imagine how much harder it would be with jack stands . . . Clearly you won’t drop the tank unless it’s nearly empty You’ll have a helper And you have a spare car to drive, in case something goes wrong Correct . . . ?! ---
**Author:** ![EMILE.N.TABBAL\_160839](https://avatars.discourse-cdn.com/v4/letter/e/ee59a6/32.png) [@EMILE.N.TABBAL\_160839](https://community.cartalk.com/u/EMILE.N.TABBAL_160839)\ **Post date:** [December 15, 2019, 11:23pm UTC](https://community.cartalk.com/t/engine-will-crank-but-won-t-start-unless-you-spray-starter-fluid-or-fuel-in-it/154538/29 "2019-12-15T23:23:10Z")
yup thats why i was trying to leave that till the end and till the tank is nearly empty thanks for the tips ---
**Author:** ![oldtimer-11](https://avatars.discourse-cdn.com/v4/letter/o/e79b87/32.png) [@oldtimer-11](https://community.cartalk.com/u/oldtimer-11)\ **Post date:** [December 16, 2019, 8:19am UTC](https://community.cartalk.com/t/engine-will-crank-but-won-t-start-unless-you-spray-starter-fluid-or-fuel-in-it/154538/30 "2019-12-16T08:19:49Z")
Why is almost everyone ignoring the OPs statement that if he hooks 12volts to a wire under the hood, the car starts and runs normally. How can it be a fuel pump problem??? ---
**Author:** ![shanonia](https://avatars.discourse-cdn.com/v4/letter/s/9de053/32.png) [@shanonia](https://community.cartalk.com/u/shanonia)\ **Post date:** [December 16, 2019, 3:58pm UTC](https://community.cartalk.com/t/engine-will-crank-but-won-t-start-unless-you-spray-starter-fluid-or-fuel-in-it/154538/31 "2019-12-16T15:58:09Z")
Ditto. The fuel pump runs and the car “starts as if nothing is wrong” when he hooks up 12V to the fuel pump via a wire under the hood. This suggests power is not getting to the FP via its normal route: that would include the ignition switch, the FP relay, possibly a computer, oil pressure switch, etc., etc. ---
**Author:** ![bing](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/bing/32/4619_2.png) [@bing](https://community.cartalk.com/u/bing)\ **Post date:** [December 16, 2019, 5:06pm UTC](https://community.cartalk.com/t/engine-will-crank-but-won-t-start-unless-you-spray-starter-fluid-or-fuel-in-it/154538/32 "2019-12-16T17:06:25Z")
Agree but if it is the anti drain back, energizing the pump full time may be enough to provide pressure to run where just the few seconds of the pump running when the key is turned on may not be enough to do it. So it may be just a false flag. ---
**Author:** ![EMILE.N.TABBAL\_160839](https://avatars.discourse-cdn.com/v4/letter/e/ee59a6/32.png) [@EMILE.N.TABBAL\_160839](https://community.cartalk.com/u/EMILE.N.TABBAL_160839)\ **Post date:** [December 16, 2019, 8:16pm UTC](https://community.cartalk.com/t/engine-will-crank-but-won-t-start-unless-you-spray-starter-fluid-or-fuel-in-it/154538/33 "2019-12-16T20:16:55Z")
i only need to connect the wire for starting and then disconnect it and it runs all day ---
**Author:** ![shanonia](https://avatars.discourse-cdn.com/v4/letter/s/9de053/32.png) [@shanonia](https://community.cartalk.com/u/shanonia)\ **Post date:** [December 16, 2019, 8:43pm UTC](https://community.cartalk.com/t/engine-will-crank-but-won-t-start-unless-you-spray-starter-fluid-or-fuel-in-it/154538/34 "2019-12-16T20:43:40Z")
That means your fuel pump is OK. Instead of connecting that wire, try the key dance: turn key to Run (not all the way to Start. The FP should run for a couple seconds then turn off. You may hear it. Turn key to Off, then to Run and pause a couple seconds for the FP to run again. Each time it runs it brings fuel and fuel pressure to the engine. After a few steps of this “dance” turn the key all the way to Start. I have had to do this a few times on my 1999 Honda Civic, especially when the fuel level is low and the temperature has dropped. As Tester opined above, it’s probably the anti-drainback valve in the fuel pump assembly allowing fuel pressure to drop; could also be a leaking injector or fuel pressure regulator. If the key dance works, that’s easier than any repair! ---
**Author:** ![EMILE.N.TABBAL\_160839](https://avatars.discourse-cdn.com/v4/letter/e/ee59a6/32.png) [@EMILE.N.TABBAL\_160839](https://community.cartalk.com/u/EMILE.N.TABBAL_160839)\ **Post date:** [December 16, 2019, 8:51pm UTC](https://community.cartalk.com/t/engine-will-crank-but-won-t-start-unless-you-spray-starter-fluid-or-fuel-in-it/154538/35 "2019-12-16T20:51:00Z")
the key dance didn’t work. i have a new injector assembly with new fuel regulator. its either the pump is weak which i still dint have time to borrow a pressure tester should be tested. and the relay. i will bypass the relay tomorrow morning if this works then i need a new relay if not will test the pump pressure. ---
**Author:** ![EMILE.N.TABBAL\_160839](https://avatars.discourse-cdn.com/v4/letter/e/ee59a6/32.png) [@EMILE.N.TABBAL\_160839](https://community.cartalk.com/u/EMILE.N.TABBAL_160839)\ **Post date:** [December 18, 2019, 2:14pm UTC](https://community.cartalk.com/t/engine-will-crank-but-won-t-start-unless-you-spray-starter-fluid-or-fuel-in-it/154538/36 "2019-12-18T14:14:08Z")
I just changed the relay the car had been parked for 7 hours now it took sometime but turned on i think both relay and pump need changing ---
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [January 14, 2020, 4:30am UTC](https://community.cartalk.com/t/engine-will-crank-but-won-t-start-unless-you-spray-starter-fluid-or-fuel-in-it/154538/38 "2020-01-14T04:30:42Z")
> [@oldtimer-11](#): > > Why is almost everyone ignoring the OPs statement that if he hooks 12volts to a wire under the hood, the car starts and runs normally. How can it be a fuel pump problem??? The normal starting sequence doesn’t cause the pump to run 30 seconds or more before beginning cranking. I’m presuming the OP"s test-wire-jumping method allows the pump to run for a good amount of time before they get back in the car and crank the engine. That time could be allowing the pump enough time to build the fuel pressure to the proper level to start the engine. While it seems unlikely the pump’s basic function is the problem, the clues are consistent w/ a faulty check valve. Since the check valve is part of the pump ass’y … well you get the idea. OP could have a fuel pressure hold-test performed to explore this possibility. ---
**Author:** ![EMILE.N.TABBAL\_160839](https://avatars.discourse-cdn.com/v4/letter/e/ee59a6/32.png) [@EMILE.N.TABBAL\_160839](https://community.cartalk.com/u/EMILE.N.TABBAL_160839)\ **Post date:** [January 14, 2020, 9:18pm UTC](https://community.cartalk.com/t/engine-will-crank-but-won-t-start-unless-you-spray-starter-fluid-or-fuel-in-it/154538/39 "2020-01-14T21:18:43Z")
Thank you everyone for your help it turned out to be the valve in the pump assembly its not holding fuel and its taking alot off effort for the pump to pump fuel all the way from zero to injectors i changed entire assembly and all is well now ---
**Author:** ![db4690](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/db4690/32/2583_2.png) [@db4690](https://community.cartalk.com/u/db4690)\ **Post date:** [January 14, 2020, 11:37pm UTC](https://community.cartalk.com/t/engine-will-crank-but-won-t-start-unless-you-spray-starter-fluid-or-fuel-in-it/154538/40 "2020-01-14T23:37:44Z")
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