I.P. timing

[aaklingler]

Have you tried pouring 12oz of room temp water on the ip when its hot and won't start? Are you running an additive in your fuel? It sounds like your pump is wore out.

 

[slam1]

No I havent but I will try the water trick. The pump could very well be shot, it was used and it did sit in my shop for a spell. Is there a way to test a pump before I put it on? as I have two more to try. The swap last time was relatively easy but I dont want to put on another bad pump.Another quick question,on the driver side of the pump what do the vaccum lines go to, what does it do. Could the pump be turned down , would it even run if I went the wrong way? Jon

 

[Agnem]

A warning on the water trick. That is a potentially despirate act. Do not do it, unless your ready for that the be the last thing you do before you commit the pump to the rebuilder. That said, I've taken that chance as well, and made out just fine, but you need to understand you can break it if it is NOT wore out.

 

[aaklingler]

how so, i never heard that before, it used to be a come suggestion I heard.

 

[Dirtleg]

how so, i never heard that before, it used to be a come suggestion I heard.

I'm going to hazard a guess here;

Water cools the external housing of the pump and some of the outer most working mechanisms. They shrink up a minute amount due to standard metal expansion/contraction and temperature. The deeper inner workings of the pump are not affected by the cooling of the water and do not shrink as much if at all.

If you have a worn pump whose internal clearances are overly large and thus cannot generate the necessary pressure to fire the injectors you could potentially reduce the internal clearances enough to generate the necessary pressure to get the engine fired after which time the cooler flow of fresh fuel will keep it running at a temperature where the tolerances will maintain the pressures necessary to support the engines needs.

If on the other hand your pump is not worn you have just reduced the internal clearances to an unacceptable tolerance and the pump will be forced to re-clearance itself due to unreasonably high presssures inside the pump. Possibly even metal on metal contact but I would not know if that is possible with these pumps or not. I am just going off of a self made theory here but it makes sense to me.

Someone please right my wrongs.

 

[Agnem]

It is a common suggestion, and I'm the one usually making it. We did just recently have a pump snap a shaft though after the water trick, and it is not known if it was the water or the WVO the user was running that actually killed it, so I thought I'd start throwing out that warning. Especially now that I'm associated with high performance pumps. My pump rebuilder cringes big time when I tell him we do that stuff. And as dirtleg guessed, it will cause metal to metal contact big time if the pump is in spec.

 

[aaklingler]

Alright, just checking I hadn't heard of any breaking.

 

[slam1]

Tried the water trick, no help. when I changed the pump I really didnt notice a power gain so I turned it up another flat. Big power gain but still no black smoke under load. Would this indicate a bad pump? Couldnt get my hands on a pyrometer but my manifolds are touchable even after a hard run. Still starts hard and rattles a little cold. Jon

 

[aaklingler]

So currently your only problem is hot hard start, the only thing I can think of being the problem is the pump, but it could be something else. The only way that I know of to tell if your pump is bad is to take it to a shop that rebuilds them and have them test it, they may not pick up the hot problem though. I believe the vacuum lines control the shifts of a c6.

 

[Agnem]

A slow starter can cause this. A hot engine is harder to start than a cold one.

 

[RedTruck]

A hot engine is harder to start than a cold one.

Do you mean to say hot batteries or a hot starter make an engine harder to start?

Paul

 

[slam1]

I think your right about the starter , it seems like the motor turns over a little slower than usual. Ill have it tested today. But why no smoke, should I be concerned? Truck runs good but sounds a little advanced . Jon

 

[suv7734]

But why no smoke, should I be concerned? Truck runs good but sounds a little advanced . Jon

If the timing is off it will change the sound of the engine and also have an effect on the smoke.

 

[Agnem]

I suppose the air in it is not as dense, and the compression is lower as a result. Just passing along what I've read. Sort of makes sense I guess. Although I've always thought a hot motor was easier to turn over thanks to thinner lube, and gee, maybe lower compression? I guess the starter motor will be hot too, and hot motors have more resistance than cold ones, but then the battery might have a little more juice cause it was just charged. I DON'T know!

 

[mejonz]

I had a problem like that with my starter. start up real easy cold but after running and getting warm starter would barly turn the engine. it was heat soaking causing high resisance replaced starter and no more warm hard starting.when you get your starter checked make sure the trucks warmed up it will show up as drawing excessive amount of amps. this is normaly a problem that deveolpes slowly thats why its not noticed sometimes untill your standed oneday