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New project 94 C3500 350

Good that they are all balanced, what is spec? Did nt believe I cant remember- i want to guess 155 or something.
 
135-155 is desirable from what I've read. As long as it starts and doesn't just chug oil I'm good.

Neighbor gave me a new in box heater core so that's one part down, now for cables that control the blend door and temp
 
Just pulling 1 plug at a time and spinning it over with the throttle closed, I'm surprised you got 125. These are low compression engines. If they're all within 10%, don't worry. Checking fuel pressure is difficult on these since theres no test port, ora real easy place to put one. Theres an adapter to hook one up at the throttle body, but I don't think it will work on the later trucks with the hard lines at the throttle body.
 
So you are saying the compression might be higher that I found?

I'm sure pulling all plugs would spin faster but are you saying I should have pulled the throttle body off too?
 
Also keep in mind the fuel pressure regulator is in the tbi head. So you could have good supply from the pump, but the regulator could be dumping fuel back to the tank.

Probably not likely to be your problem, but I've had a fuel pump relay give almost identical symptoms.

Sent from my SAMSUNG-SM-G935A using Tapatalk
 
When you do a compression test, you're supposed to pull all the plugs 1st, 2nd you're supposed to pull the throttle wide open, then turn it over(some only do 5 compression strokes and record while others will crank it over until max reading is obtained). You don't want the starter to be fighting but the 1 cylinder you're testing, you want the throttle wide open because it's an air pump and any restrictions will effect output. This is all done to get results for just each cylinder to be as equal as possible.
 
Do Just like Ferm said, then after recording all the cyilinders do the wet test. About 1 teaspoon of engine oil into the spark plug hole and compression test again. Only put oil into the one you are about to do. If it has no effect then the rings are showing no signs of wear and any compression loss is in the head (valves). If the oil brings compression all the way up to spec, then the rings are the issue. Then move to the next cylinder, recording findings.
 
Well I don't plan to fight the compression tester again. If my numbers came out as good as they did with a poor attempt then I'm not all that concerned. I was mostly looking for a seriously low hole as a sign of a bad head gasket. I'm just going to leave well enough alone on that front.
 
Well, yesterday the truck was an absolute dog. Today it's runs like a scalded dog and will cruise 85....

I'm thinking it just needed the throttle body cleaned out. I'm letting it cool and then I will pull the IAC and egr for a cleaning. I have poured a can of sea foam in each tank since day 1 so I might be getting the gunk out and finally everything is freeing up. (I like this senario)

I sprayed a half can of sea foam through the pcv and the top of the throttle body while removing all visible varnish.

Another issue that has been brought to my attention is the TPS can be finicky
 
IAC looks new, can't tell the brand.

Egr was clean and seemed to work ok. It did get cleaned.

Truck got its stutter back off and on now. But idle is smooth at 750 rpm as the general intended, biggest idle issue is it hunts around 900 some when cold but after about 2min warm up it locks in at 750.
 
Today the truck ran rough first thing this morning to the deer plot, ran better but still rough home, ate a piece of pie and we took it to check cows. Was rough the first 5 miles then ran flawlessly all morning (still seems a touch low on power). Shut it off for lunch, came back out and it was a bit rough through the parking lot and getting on to the main road but cleared up within 2 blocks.


So, is there a chance I am loosing fuel prime? Is there a way to test this?


On my 6.5's I've had the pick up tube in the tank rot and get pin holes. Any chance I'm getting air in my fuel and loosing prime after shutting off for a time?
 
Easiest is start it wand watch for bubbles in the clear fuel line. If Bubbles clear up some when it starts running better- then that is it.

Also a pressure gauge on there- your fuel pump will pressurize the fuel to say 8 psi. Then when it runs better it jumps up to 10 psi. That could be air in the line. But The pressure should build in less than a minute, not after a few minutes if it is bleed off or air.

If you let the truck warm up to full temperature does it have the same problem?

Are you getting a blended fuel for anti gelling?
 
You very well could be low on fuel pressure causing this. Gotta get a gauge on it and see what the pressure is under load. The TBI trucks use a SMALL low pressure pump. These systems run best at 12-13 PSI, and the TBI pump is lucky to hold 13.5 psi if you do a max pressure test on one.
 
After I scare all the deer off I plan to cobble the fuel psi in.

Where would I add a clear line since it's hard line all the way to TBI?
 
If you let the truck warm up to full temperature does it have the same problem?

Are you getting a blended fuel for anti gelling?[/QUOTE]

The truck idles 5min before I ever leave in the mornings
 
There was a kit for it that had 1 male and 1 female barbed fittings, and about 8-10" piece of clear line with hose clamps. You were supposed to undo the line at the engine and by moving it over a little, install the clear line in a loop.

Air in the line in gas engine is more akin to a vapor locking situation than it is like a diesel. Your looking for contamination as much as the bubble trail.

Up to temp- the thing doesnt have a choke like carburetors, it uses a temp sensor to tell it how cold the engine is, and over fuels accordingly. The "choke circuit" had frequent issues in my experience. If you are having most of the problems while engine coolant is below 170 - that could be your issue. I always kept a known good sensor to swap in, and cleaned connections with spray cleaner and a brass brush. It seemed ones from rusty areas always had more choke problems.

My anti gel coment was supposed to have been followed with a laughing emoji as a joke, but I didnt click it right. Will wrecks another sarcastic line- sorry about that...
 
Will L. said:
My anti gel coment was supposed to have been followed with a laughing emoji as a joke, but I didnt click it right. Will wrecks another sarcastic line- sorry about that...
Click to expand...
I was going to bring you to task about that Will, then thought how often I forget what the original post was about.:)
 
Haha, I was stumped on the anti jail gas!

Soooo..... the wee little gauge says 6-8psi cruising and 2 attempting wot... guess it's time to up size the tank, external pump, with @Burning oil metrum rod
 
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