2.8L V6 wont stay running. When running it hesitates. It hesitated when I tried to drive it.

[MadMax_636]

So, yesterday I tried to clean up some of the cable mess to I could get and see the oil filter adapter and a lot of ignition cables were loose under the hood and I found a few that were kinda baked onto the manifold. So I cleaned them up and noticed the cabled to the junk distributor were worn out and ragged looking.

Im thinking its a wiring issue to my distributor is on and off but mostly off. Since the vacuum keeps dropping and is VERY low but when I have it at high idle it "runs" and with the choke closed. So Im thinking its a timing issue as well as advance issue.

Has anyone else has this issue and know how to fix it? I do want to do the duraspart mod but I dont really have the kind of money to do all of that. Since Im saving to rebuild the engine this summer.

 

[RonD]

While you may have a spark issue as well, it reads more like a larger vacuum leak is the main problem

Plug PCV Valve hose and Power brake hose, to see if either is leaking


Duraspark distributor with HEI module is best, and cheapest, conversion for spark

 

[MadMax_636]

While you may have a spark issue as well, it reads more like a larger vacuum leak is the main problem

Plug PCV Valve hose and Power brake hose, to see if either is leaking


Duraspark distributor with HEI module is best, and cheapest, conversion for spark

That was my first thing to try. I plugged both and it still keeps acting the same way. When I went to "Drive" her she hesitated and acted like what felt like a vacuum leak or bad power valve. So I plugged the PCV and it still acted the same. The stumbling happened even at idle. So I dont think its the power valve.

Im thinking about rebuilding the motor before I do the duraspark mod. Since Id rather put new parts on a new/fresh motor than a old motor.

 

[MadMax_636]

While you may have a spark issue as well, it reads more like a larger vacuum leak is the main problem

Plug PCV Valve hose and Power brake hose, to see if either is leaking


Duraspark distributor with HEI module is best, and cheapest, conversion for spark

Here are the videos of the truck running.

The last part of the video with the camera on the vacuum gauge was holding at a steady throttle.

 

[RobbieD]

Dude, your luck runs like mine- if it ain't bad, then it's just plain shitty.

Just some thoughts, for what it's worth.
I can understand your wanting to convert to Duraspark on a newly rebuilt motor, but it may make more sense to go ahead and do the conversion now. If I was at the point you're at, I'd step back away from it for a minute and reconsider some things.
CON
1) The original engine management system sucked, even when it was new. With its complication, age, and wear, the engine may not run decently now, without having to sink more money in "temporary" parts (considering your future plans).
2) Your current engine management system uses a lot of vacuum lines and devices; in your video it's obvious the vacuum system is pooched and needs repair (more time and $$$).
PRO
1) Your carb (which looks good, BTW) can be reused. I rebuilt my original 2150A, and fabbed the metering block to replace the idle mixture solenoid; it works great. This saves a major expense in the conversion.
2) You'll be getting rid of a problematic (and failed) engine management system, and in the process removing a ton of junk, which leaves you with a greatly simplified engine compartment, and an engine with ignition and fuel systems in its most basic, easy-to-work with form.
3) If you convert now, as long as the engine is in basic good shape (I.e.- compression, oil pressure, doesn't overheat) your truck will be a lot more driveable and dependable. This buys you time to better plan, finance, and execute your engine rebuild later. Your Duraspark parts would simply reinstall, and this will save time and complication when you do tackle the engine rebuild.

I'm not trying to tell you what to do here, but sometimes a different perspective may help, when a person is weighing out all of their options. Good luck, man, with whatever direction you take; we're all pulling for you to whip this beast.

 

[MadMax_636]

Dude, your luck runs like mine- if it ain't bad, then it's just plain shitty.

Just some thoughts, for what it's worth.
I can understand your wanting to convert to Duraspark on a newly rebuilt motor, but it may make more sense to go ahead and do the conversion now. If I was at the point you're at, I'd step back away from it for a minute and reconsider some things.
CON
1) The original engine management system sucked, even when it was new. With its complication, age, and wear, the engine may not run decently now, without having to sink more money in "temporary" parts (considering your future plans).
2) Your current engine management system uses a lot of vacuum lines and devices; in your video it's obvious the vacuum system is pooched and needs repair (more time and $$$).
PRO
1) Your carb (which looks good, BTW) can be reused. I rebuilt my original 2150A, and fabbed the metering block to replace the idle mixture solenoid; it works great. This saves a major expense in the conversion.
2) You'll be getting rid of a problematic (and failed) engine management system, and in the process removing a ton of junk, which leaves you with a greatly simplified engine compartment, and an engine with ignition and fuel systems in its most basic, easy-to-work with form.
3) If you convert now, as long as the engine is in basic good shape (I.e.- compression, oil pressure, doesn't overheat) your truck will be a lot more driveable and dependable. This buys you time to better plan, finance, and execute your engine rebuild later. Your Duraspark parts would simply reinstall, and this will save time and complication when you do tackle the engine rebuild.

I'm not trying to tell you what to do here, but sometimes a different perspective may help, when a person is weighing out all of their options. Good luck, man, with whatever direction you take; we're all pulling for you to whip this beast.

Thanks a WHOLE lot dude!!! After reading your post I think I might try and tackle that. Since the wiring is horrible and is probably the fault to a lot of my issues (Besides my worn out engine haha) The only thing Im scared of is working with the wiring. I work with computers and all of that. I build PC board level type stuff. The only thing Ive never really done is vehicle wiring. Since the reason Im scared of the whole thing is because If I screw anything up its off the to just yard to maybe find a new harness. I looked on ebay and couldn't find one at all.

I tried to follow the written guide but it was just to confusing since Im more of a visual person and Im also dyslexic. I like watching videos or having someone there with me showing me what things are and how to do them. Thats how I learned most of the stuff I know today regarding computers.

Since Ive got most of next week off work. I might try and tackle the wiring. The only thing is that the parts list on the page on here are scattered and Id like to buy them from one place. I think I can get the distributor on Rockauto but idk about everything else.

How much does the whole conversion cost roughly?

Thanks about the carb, Shes brand new! Shes a 300 CFM carb. What you said makes a lot of sense.

 

[RobbieD]

I can do wiring but I suck at computers; maybe we can work out a deal. : )

Seriously, the wiring is not difficult. You'll be freaking out at all of the crap you'll be pulling out of the truck, and once you get over that the wiring is a piece of cake.

If you're ready to tackle it I'll try to help you out as much as I can. I did mine over 10 years ago, but I've still got pics and notes, and I've still got my '84 so I can use it as a reference (aka "Chinese blueprint").

There's also a lot of other folks on here that have done this conversion, so there's a good information base and knowledge pool.

 

[MadMax_636]

I can do wiring but I suck at computers; maybe we can work out a deal. : )

Seriously, the wiring is not difficult. You'll be freaking out at all of the crap you'll be pulling out of the truck, and once you get over that the wiring is a piece of cake.

If you're ready to tackle it I'll try to help you out as much as I can. I did mine over 10 years ago, but I've still got pics and notes, and I've still got my '84 so I can use it as a reference (aka "Chinese blueprint").

There's also a lot of other folks on here that have done this conversion, so there's a good information base and knowledge pool.

Thanks! What kind of deal? lol

Yeah, It saw the photos you posted on a post I made a while back about this and it looks easy but the amount of stuff you pulled out is scary. Mainly because I didnt know what half that shit was or does. Im just worried about cutting something to short, the wrong thing, frying something (Something you cant replace (new or NOS or off a parts truck)

 

[AndyB.]

Some of the wires you show as disconnected in your video are vacuum lines. I’d check to see if any of those are still hooked up to a manifold port ace if they need to be capped off.

How does the choke work? It looks like the butterfly up top was binding. Without power going to the heater in the choke thermostat, does it open or close at all?

There are replacement connectors for the TFI module—but I don’t know how this would work. You showed disconnected wires for the throttle position sensor (I don’t think you can hook one up to that carburetor) and the knock sensor. I don’t know how the ECU could advance the timing without those inputs.

 

[MadMax_636]

Some of the wires you show as disconnected in your video are vacuum lines. I’d check to see if any of those are still hooked up to a manifold port ace if they need to be capped off.

How does the choke work? It looks like the butterfly up top was binding. Without power going to the heater in the choke thermostat, does it open or close at all?

There are replacement connectors for the TFI module—but I don’t know how this would work. You showed disconnected wires for the throttle position sensor (I don’t think you can hook one up to that carburetor) and the knock sensor. I don’t know how the ECU could advance the timing without those inputs.

I know of 1 wire thats sucking air. I found another but its super melted and I found it cooked to the exhaust manifold......
It runs back to around the passenger side wiring wall. Basically everything is wrapped in 35+ year old cable covers. Hard to move and hard to remove. So I haven't touched it since idk how bad the wires are inside them and I didnt want to worry about doing more damage or having cables getting onto or into things they shouldn't.

The choke is a hot air. Not power going to it or air/heat tubes going to it. It runs off of the heat from that comes off the engine.

The throttle position sensor was ruined. I had to heat it up to even get it off the old carb. The other sensors. Idk

Before yesterday when I messed with the wiring it ran perfectly. Fast and strong. So idk if that means anything about those sensors. The throttle sensor has be gone for months....

 

[MadMax_636]

Heres a video of just the wiring. I tried to show everything I could.

 

[AndyB.]

I think you’re so far from having all the pieces in place for the TFI module to work correctly, your best bet is to replace the distributor with an earlier deign.

Most vacuum devices will pull of the vacuum reservoir (coffee can looking thing). Originally, on the passenger side rear of the EGR spacer under the carburetor would have been a screw in adapter with vacuum nipples. I’d get a pack of vacuum caps and disconnect the lines going there and cap them off.

 

[MadMax_636]

I think you’re so far from having all the pieces in place for the TFI module to work correctly, your best bet is to replace the distributor with an earlier deign.

Most vacuum devices will pull of the vacuum reservoir (coffee can looking thing). Originally, on the passenger side rear of the EGR spacer under the carburetor would have been a screw in adapter with vacuum nipples. I’d get a pack of vacuum caps and disconnect the lines going there and cap them off.

I got the parts list for the duraspark mod set up in a cart on rock auto. Its around $145 so yeah. I think ill do that.

As for the vacuum stuff you spoke of. I wouldnt even know where to start. A lot of the stuff behind the carb is capped (With screws in hoses) or have stuff hooked up to them As hopefully seen in the video.

 

[RobbieD]

You are looking for the "tree" shown below, which screws into the manifold behind and below the carb.

Follow @AndyB. 's advice, and remove the hoses and cap the open tubes on the tree. In this picture, pointing toward the camera is an open tube, left, and a capped tube to the right of it. Caps would be best, but for temporary testing you can wrap electrical tape around the tree to close the tubes. An open tube is a vacuum leak.

 

[MadMax_636]

You are looking for the "tree" shown below, which screws into the manifold behind and below the carb.
View attachment 40110

Follow @AndyB. 's advice, and remove the hoses and cap the open tubes on the tree. In this picture, pointing toward the camera is an open tube, left, and a capped tube to the right of it. Caps would be best, but for temporary testing you can wrap electrical tape around the tree to close the tubes. An open tube is a vacuum leak.

I might have removed them slightly by accident and that might be part of my temp issue. Ive got caps so Ill remove the weird things hooked up to them and recap them all up.

Ill see about capping them off and see if that fixes anything

Thank you all for the encouragement and help! Im truly grateful for all of it!!!