5.7 difficult to start on and off --- Any ideas ?

[ab59]

Hey guys , was out fishing yesterday and have been working out a few bugs in the engine and have figured out a few but the engine not wanting to start every time has me a little stumped. It will fire right up one time and then sometimes I have to crank on it for quite a while before it will start. Warmed up or cold it does not seem to matter . Plugs are new and so is the carb as well as the engine. Runs great once running but I had to set the idle up a little yesterday as it wanted to die after starting sometimes. Had been idling just fine after starting . All of these symptoms are intermittent .
Any ideas ?
thanks , A.B.

 

[Scott Danforth]

first of all.....

what 5.7?
what vintage? 70's? 80s? 90s?
what induction system? 2-barrel, 4-barrel? Rochester? Holley? Edelbrock?
what ignition system?

next, how are you starting it cold? how are you starting it warm?

have you done any maintenance.... you state the plugs are new, the carb as well as the engine. however has it been adjusted properly? has it been maintained

 

[ab59]

Thanks for your reply---- I do not know what year model the 5.7 is. I removed a 1988 5.7 and ordered a rebuilt of the same vintage however when I tried to mount my intake manifold on the rebuilt engine , I found that the bolt holes did not line up and were at a different angle than the original. So I do not know what year specifically however I would hazard a guess that it is from 1989-1994 Pre or not a Vortec . I am running a Holley 4010 4bbl carburetor that is adjusted correctly. I just changed the fuel filter as well as the oil after 8 hrs break in time.
I am running a real not converted Mallory Electronic ignition . the timing although 1 degree off at 4 btdc instead of 3 is close enough for now.
The Holley has an electric choke that when observed without the flame arrestor on it functions as it should. T|he fuel level in the bowls is at the bottom of the inspection holes where it should be.
I start it the same way warm or cold . Sometime it fires up the second I hit the key , warm or cold, and sometime I have to crank the engine for much longer that I would like to get it started.
I have a suspicion of what it could be but wanted ideas before i spoke it .
thanks---A.B.

 

[alldodge]

Sounds to me to be a ignition issue, your getting gas, just no spark or not enough

 

[ab59]

Thanks for your reply---- Could this be caused by a an anti siphon valve ? It seems as if I'm may not be getting fuel right away sometimes and takes a minute or two to pump gas back to the carburetor . Runs great now at higher speeds . I will go ahead and order a new cap and maybe some wires though . I skipped those as the cost of my restore shot out of sight but should not have.

 

[alldodge]

Don't see an intermittent issue coming from fuel with your comment of

The fuel level in the bowls is at the bottom of the inspection holes where it should be.

Find out if you are loosing spark, take a timing light along and place on coil wire to see if it flashes

 

[ab59]

Got ya. I will throw the timing lite in the boat and make a trip to Shasta where I can test and fish all day.

 

[Bondo]

It will fire right up one time and then sometimes I have to crank on it for quite a while before it will start.

Ayuh,...... Are you advancin' the throttle, when startin' it,..??

It's carb, not Efi, 'n usually needs a bit of throttle,.....

 

[ab59]

thanks for your reply Bondo-- Don't think I can throttle it up with my controller , has to go in gear to throttle up . No button to bypass and is a single stick . Would sure help if I could give it a little more throttle when starting though.

thanks ---A.,B.

 

[Bondo]

Ayuh,..... Pull out on the lever,.....

 

[Lou C]

If you have the OE OMC controller like I do on my boat, you pull it out as Bondo says, then can advance with it in neutral. If it has the push button in the middle, push that and then you release the shift system. Basically there are 2 types of controllers. The Teleflex aftermarket ones have the push button. With a carbed engine you pretty much always have to give a bit of throttle even on a hot start. At one time...all our cars were that way....in the pre throttle body and EFI days....

PS if your intake has only 8 bolts then the engine is a Vortec, if its got 12 it is the pre-Vortec….

 

[Scott Danforth]

I go back to post #2

ab59 how are you starting it cold, how are you starting it hot. be specific

 

[ab59]

Hey Lou-- I have a Teleflex controller but there is no button in the center , I have had others in the past that did , so hopefully it pulls out . I will see after i finish replacing the capacitors on the power supply for our plasma tv. Hope that's all it is needing is a little prime.
Scott Danforth--- I just turn the key to start the engine. It has an electric choke so there is nothing else to be done . Well as far as I know anyway .
thanks for all your replies----Bruce
P.s. the site is demanding that i post a picture or it will not load my post so i'm just uploading a picture of no real relation to our subject---

 

[Scott Danforth]

I just turn the key to start the engine. It has an electric choke so there is nothing else to be done . Well as far as I know anyway .

and that is where you are wrong.

cold start - 1 to 2 full throttle motions. this sets the choke and primes the carb. only you will know if you need one or two full pumps of the throttle, as each motor is slightly different.. this doesnt mater if the drive is in gear or not..

then pull the handle out to throttle only, and move to 1/3 throttle. then turn key. when motor fires, back off RPM to 1500 RPM for about a minute (no cold idle cam on a boat carb). then you may pull away from the dock.

when its warm, just turn the key. if it sits for a while, you may need to advance throttle to prime.

quit thinking modern vehicle and think more like 1975 pickup truck with a carb. two pumps and turn the key

 

[ab59]

First of all let me say thanks to all of your replies----- Once again you are all right and I can pull the controller arm out and throttle up without being in gear. Something that I obviously did not know ! Hopefully this was my problem and now that you guys clued me in , I will not have any more problems with it.
I do not usually fish or boat on the weekends so maybe Tuesday I will go to the lake and give it a good test and see. Last time I got talked into fishing on a week end someone hit the front of my Tundra and left me 1500.00 in damage to my front bumper , no note , just damage so Tuesday is my target date.
Thank you all for your advise and knowledge---------Bruce

 

[Lou C]

Ever had cars with carbs and auto chokes? every one of them was a little different. My '88 4.3 takes 3 pumps to full throttle then back to 1/3 open, if used recently starts right up, if not used for week or more takes 3 crank overs to start from cold. Warm, throttle slightly open starts instantly like an EFI engine.

 

[PITBoat]

and that is where you are wrong.

cold start - 1 to 2 full throttle motions. this sets the choke and primes the carb. only you will know if you need one or two full pumps of the throttle, as each motor is slightly different.. this doesnt mater if the drive is in gear or not..

then pull the handle out to throttle only, and move to 1/3 throttle. then turn key. when motor fires, back off RPM to 1500 RPM for about a minute (no cold idle cam on a boat carb). then you may pull away from the dock.

when its warm, just turn the key. if it sits for a while, you may need to advance throttle to prime.

quit thinking modern vehicle and think more like 1975 pickup truck with a carb. two pumps and turn the key

Exactly. It tells you right what to do under the sunvisor on my '74 GMC - one or two full throttle pumps and release when cold, depress and hold about halfway when warm.

My 2bbl carb boat fires right up after sitting for weeks with that method. Out on the lake warm, I have to crack the throttle open a bit just as prescribed above, or it doesn't want to start right away.

I asked to see the first start of the day when I went to look at it before purchase, and the PO obliged. He worked the throttle like a pump handle while cranking, and it took several seconds to fire up. I'm thinking your starter ain't gonna last as long as it should like that.

Having learned to drive on carbbed cars helps a lot. Although the correct method still escapes some who were alive back then, and ought to know...

 

[ab59]

Thanks guys , I kinda figured that I would just treat it like my old 1970 GMC 3/4 ton pickup and hit the accelerator 2 or 3 times and then turn the key . It had a 4 bbl and a 350 in it as well

thanks again--------------------- Bruce