Bluieprint 383 stroker ISSUES Bad idle.

[kevin lefebvre]

Took the engine out for a first long drive to the cottage... Everything bad happened to me. Brace yourself for the short version.

Keep in mind engine has about 200km on it. its new...

So first off I was driving, almost arrived at destination truck stalls. I check for issues, I see that plug #3 wire is burnt at the boot. So possibly grounding itself, but I still had to make it back home. Once I get home I see that plug 1and3 wires are burnt bad on the headers. So I change out plug wires and now the truck will not start at all. No spark.

2: I changed the rotor, cap, ignition module and swapped out all the parts with one another with the distributor that blueprint has on the engine, with a MSD one I had on my old 350 that I swapped this engine out for. NOTHINH WORKED, NO SPARK. Im not great mechanically so my last ditch option was to swap out my whole distributor itself... So i did with the MSD one I had. Trucked turned over but was back firing like hell and not idling at all. Turns out I messed up and the rotor wasnt towards cylinder one, more on three. So I took it out and put it in right position. Truck fired right up but idle bounced up and down 1000-500- 1000-800... Just didnt idle properly and seems like it wants to shut off. But idles well above 1100rpm.

Now this is where im at... Plugs are either BLACK and Full of GAS, Or MATTE BLACK.
Can the carb be bad, timing ? Its hard trying to time it because it idles bad. I dont know what the issue could be. Bad advance on the distributor since it was on my 350? I have no idea.

 

[1979k10]

Did you install the distributor 180 out?

 

[Vbb199]

The initial distributor problems and burnt wires sounds like a bad ground at the coil


The second issue sounds like vacuum leaks to me.

Erratic idle and overfueling (fowled plugs etc) is usually a sign of a vacuum leak

Or...... is there a vacuum advance on the distributor? If you aren't using it, is it capped off on both the dizzy can and the back of the carb?

Thirdly , what's regulating the fuel pressure ?

 

[Bextreme04]

Or...... is there a vacuum advance on the distributor? If you aren't using it, is it capped off on both the dizzy can and the back of the carb?

DO NOT cap at the distributor(or any vacuum can). If you cap the air inside a vacuum can, you will get fluctuations of the can due to temperature changes. A sealed space will change pressure directly in relation to temperature. So if you put a cap on it when it is hot, it will have a vacuum generated inside the can when it cools down and will apply the advance until it heats up again. Always leave unused vacuum cans un capped.

Also, he is right about making sure you have no vacuum leaks, including internally on the intake gaskets. If you have a vacuum leak from an intake gasket into the valley, you're going to have big problems that are hard to diagnose.

 

[Vbb199]

DO NOT cap at the distributor(or any vacuum can). If you cap the air inside a vacuum can, you will get fluctuations of the can due to temperature changes. A sealed space will change pressure directly in relation to temperature. So if you put a cap on it when it is hot, it will have a vacuum generated inside the can when it cools down and will apply the advance until it heats up again. Always leave unused vacuum cans un capped.

Also, he is right about making sure you have no vacuum leaks, including internally on the intake gaskets. If you have a vacuum leak from an intake gasket into the valley, you're going to have big problems that are hard to diagnose.

You're absolutely right. I dunno why I didn't think about that lol

 

[scrap--metal]

I had idle troubles with my old '84 K10, though it wasn't a brand new engine. One day it wouldn't stay running on the way home from hunting unless I feathered the throttle. Driving down the road it was okay.

Somehow the screws holding the carb to the intake had gotten loose creating a vacuum leak.

Once you're confident that the timing is set right, look for vacuum leaks with some starting fluid.

 

[QBuff02]

I'd start out with finding true top dead center on #1 and verify firing order at distributor and then retiming the engine properly and going from there.

 

[HEG77k10]

I’d be willing to bet your carb is the issue for fouling the plugs. What kind of carb are you running? And do you have fuel pressure regulator?

 

[50dan]

Carb and timing.
Run a Holley 750DP they love 383 strokers. Engine is not your problem.

 

[HEG77k10]

I just took an 850 double pumper (message me if anyone wants to buy it) off my 400 stroker and swapped it for an Edelbrock avs2 650, I thought it was gonna be to small but it made a huge difference in how smooth it ran. Perfect for a daily driver