1st problem after 4 k miles

[dalwine250]

i bought the ty in march,i have my 1st problem.when i try to start after being warm,i have to crank for a long time till it starts.also,when warm,idling in park,rpm's wander between 600 nnd 1000 rpms.i can kinda feel it while decellerating.i have no data master or anything so i'm hoping you guys can point me in the right direction.any help will be greatly apprieciated.dave

 

[PPI Typhoon]

Re: 1st problem after 4 k miles

Have you done any sort of tuneup since you've purchased the truck?? I'd do the plugs, wires, cap, rotor, ignition module, all filters, etc.

That might solve a lot of it. You also may want to consider that problem being fuel related which could either be a fuel filter, or fuel pump being weak when hot, causing longer crank times. (I've had this happen with a pump that was on it's way out).

 

[dalwine250]

Re: 1st problem after 4 k miles

the ty runs so good other than these problems.i will do the tune-up.if that isnt it ,what do think about egr and iac ? for the idle problem.dave

 

[PPI Typhoon]

Re: 1st problem after 4 k miles

Well, whenever you've purchased a new truck, it's always nice to have a starting point. This way, you KNOW what's been replaced, and have something to compare to.

Before you go looking at the expensive stuff, I'd do the tuneup (which should be done anyways) and then worry about the bigger things. That way you kill two birds with one stone.

But that's just an opinion.......

 

[dalwine250]

Re: 1st problem after 4 k miles

i totally agree,thanks for the input :tup:

 

[gmcturbo]

Re: 1st problem after 4 k miles

hook up a fuel pressure gauge and re-create the circumsances this happens at and look for fuel pressure dropping off when trying to start

 

[dalwine250]

Re: 1st problem after 4 k miles

well...i put a fuel presure guage on.key on......15 lbs.while engine running......50 lbs.key off straight to 0.does not hold any line presure.is this normal..
dave

 

[gmcturbo]

Re: 1st problem after 4 k miles

no that isnt normal and thats probably your problem. you probably either have a bad fuel pump or leaking injector, fuel pressure regulator, or fuel pump check valve.

is there any fuel in your oil? if so stop driving it as it will wash the oil off the cylinder walls and mess up your rings

 

[Timbo]

Re: 1st problem after 4 k miles

no that isnt normal and thats probably your problem. you probably either have a bad fuel pump or leaking injector, fuel pressure regulator, or fuel pump check valve.

is there any fuel in your oil? if so stop driving it as it will wash the oil off the cylinder walls and mess up your rings

I think you're reading it wrong. My interpretation is...
Key on: 15psi
Engine running: 50psi
Key off: 0psi.

I don't think that's bad.
Mind you, my fuel system isn't stock, so I could be wrong about that.
I would want to know what your fuel pressure does under acceleration.

 

[dalwine250]

Re: 1st problem after 4 k miles

oil looks good.the next thing i do tonight is order a pump,reg,complete tune up.thanks for your help ,you gentlemen are awsome.having you guys at aur newbe fingers is too cool.i'll try not to abuse you.thanks again, dave

 

[dalwine250]

Re: 1st problem after 4 k miles

key on-15lbs......while crankink-15lbs. after start.it slowly goes to 50.....key off - 0.. turn key right back on -0lbs.hope that helps

 

[Timbo]

Re: 1st problem after 4 k miles

key on-15lbs......while crankink-15lbs. after start.it slowly goes to 50.....key off - 0.. turn key right back on -0lbs.hope that helps

Sounds like your pump is about dead if it takes a while to get to 50psi.

 

[gmcturbo]

Re: 1st problem after 4 k miles

i understood it

 

[gmcturbo]

Re: 1st problem after 4 k miles

oil looks good.the next thing i do tonight is order a pump,reg,complete tune up.thanks for your help ,you gentlemen are awsome.having you guys at aur newbe fingers is too cool.i'll try not to abuse you.thanks again, dave

thats stuff's really what any new owner should do anyways, extra nice if it fixes a driveability issue too!

when i went through my fuel system, i had the injectors flow tested and cleaned, i think it was worth the time and $65 on these 12 year old injectors. i dont know if it helped any, but its good to know theyre not clogged

 

[Don W.]

Re: 1st problem after 4 k miles

Looks like we have you on the right track.

Checked the manual and in a nutshell it says check fuel pressure, do a tune up, and check grounds. The fuel pump only runs for 2 secs if you’re not cranking so if fuel pressure drops after key on and no cranking I suspect a fuel leak (bad injector or ?) or bad fuel pump. With a stock FP my Sy imediatly jumps to 40psi and stays there.

If your truck still wanders in idle speed after fixing/confirming fule pressure let us know. Problems there are often vacuum leak related.

 

[dalwine250]

Re: 1st problem after 4 k miles

thanks everyone,i'll get the pump in next week,i'll let ya know how it runs after......dave

 

[blk00z28]

Re: 1st problem after 4 k miles

What mods to the truck btw?

50psi might be to much if you have small injectors :dunno:

 

[dalwine250]

Re: 1st problem after 4 k miles

this truck was owned by msd,i believe the ony mods are borla exhaust,bear brakes and pillar pod.msd coil and wires.other than that i believe
. dave

 

[dalwine250]

Re: 1st problem after 4 k miles

put the new walbro in tonight,solved my problems.thanks for all you help.dave