1993 6.5 Runs bad until warm

[fishshallow]

Im new to the forum and my truck does the same thing, its only when its cool outside. I have a 93 2500 with 260,000 miles. Mine doesnt die but it runs bad until it warms up. i joined cuz my truck has a few problems and im a college student short on funds so i cant do much experimenting to find out whats wrong. On thing i did try last winter was changing the glow plugs, it didnt help anything but atleast a have new glow plugs. I hope you figure out what the problem is b/c i always feel like my truck is on the verg of death!

[john8662]

Post was moved into a new thread to not hijack another thread...

With 260k miles on the engine a few components are quite ready for replacement. The main thing that comes to mind is the health of the injection system and of the timing chain.

I'd start with a new chain and gears for the front of the engine, At about 150k miles on a 6.5 the timing chain has stetched significantly, and usually warrants replacement. You will need to replace the crank gear, cam gear and the chain itself, they can be bought as a set (recommended). Once replaced this will help regain engine timing.

To tell whether you should replace the components, you can advance the injection timing and see if you get any improvement.

1993 6.5's are Mechanically injected, 1994 and on 6.5's have electronic fuel injection, totally different.

Please take some time to explore posts via the "Search" feature found in the blue bar near the top of this page.

Things to search for: Timing chain replacement, advancing timing, injection pump replacement and anything else you're curious about.

J

[DaveBr]

Hello Fishshallow - welcome to the page. I had the same issue on my 93. Check to see if your lift pump is working. It is located on your drivers side frame rail and it looks like a fuel filter but it will have two wires coming out of it. Put your hand on it when the truck is running and you should be able to feel it working. It will not hum like a normal electric pump. It should feel like it is pulsing or ticking. If you feel nothing then it's not working. This means that there is a good chance your pump is dead or your oil pressure switch is not activating the pump. Check it out and let us know. As John mentioned check out other threads on this forum - it's a good way to learn about issues and fixes that are common or uncommon with these rigs.

[daustin]

First thing i'd do is a compression check with that many miles on the clock. That should be approx 380-420 on a healthy engine with the variance between cylinders not more than 15-20 PSI. If that checks out ok, then i'd look at the other things.
Don

[Robyn]

John 8662 is right on with the timing.

I will say this, the sprockets (gears) seem to hold up well and many times one can replace the chain only on these and all is well again .

I did my 94 at 200+++ miles and the gears were fine. As long as the sprocket teeth dont have any nasty wear or hook to them and a new chain will lay nicely over the sprockets without showing a tendency to "NOT FIT" your good to go with just a chain.

NOW the biggy is the injectors on these things. I can safely say that at 260K the injectors are shot.

They lose POP pressure (Point at which they open to spray fuel) once the pressure drops off they also start to slobber and pee a stream rather than spray a fine mist of fuel.

The nozzle wears out and so it goes.

Poor or worn out injectors will show up as a hard cold start with only a few cylinders hitting at first and with huge amounts of whitish blue smoke out the tail pipe.

The poor little creature will shudder and shake and rock and roll until it gets some heat then smooth out.

The IP could be in need of service too but a set of injectors would be my first stop.

You dont have to do it all at once but the injectors will probably help things big time.

The timing chain will certainly fix an issue of importance and of course a fresh IP will do wonders too.

The injectors are easy to do and will not hurt too bad $$$$$$$$$

Stay away from ebay stuff.
Have a local diesel injector/pump shop refurbishm yours.

Hope this helps

Robyn

[fishshallow]

Thanks for the help guys, i guess i will start with the injectors and go from there. I guess my only question would be which one of these problems can cause the most damage to my engine if not attended to promptly. Im short on money so things tend to take longer than expected to fix.

[rustyk]

The timing chain would seem to be the most critical, but I've not heard of one breaking - but a stretched chain can affect performance. Injectors, however, failing to atomize, can send droplets of fuel into the cylinders, and these can scrub the engine oil off the cylinder walls, not good.

If it were I, I'd first pull the injectors, have them tested, set, and overhauled. If you're lucky, not all will be in need of rebuild or replacement.

[DaveBr]

Don't forget to check your lift pump. It doesn't cost anything to find out if it's working. If it isn't it can contribute to your problem.

[fishshallow]

I checked the lift pump under the driver side door by feeling for a ticking, but all i could feel was the vibration from the engine. How much do they cost and how hard are they to swap out, im pretty sure that mine is not working. And i was thinking that i would change the timing chain as well does anybody have a guestimation on the cost of a knew one and an install.