Something is makin' her hold back...

[OCD Boss]

I have been working on my 1980 D50 Sport for a little bit now. So far I have replaced the radiator, done 2 oil changes in the past 2 months (mostly due to the fact that it hadn't received an oil change in probably years, and it was already black after a week of driving). I have had some work done on the steering and front end. As well as run some fuel additives through some premium gas.

After all this work, not that it's that much, but she sounds much better at an idle. However when driving, just feels like something is holding her back when I hit the gas. Almost like it still has the e-brake partially on. I know that it isn't the e-brake because when I put it in neutral and coast, it coasts just fine.

I have a Fram air filter in the air box right now, but I have considered getting a K&N, thinking it might be an air flow issue. I don't know where to start on this one. Any thoughts?

[DroppedMitsu]

If you havent already then I would replace the fuel filter, should be on the drivers side up under the bed on the side of the gas tank, its not too difficult to change unless you have really big hands.

[OCD Boss]

Alright, I will definitely try that. Also if anybody could tell me if they think that it could possibly be related to a bad Carb., that would be great as well. I'm just curious to see if it's the whole fuel delivery system all together. But it's just a thought.

[DroppedMitsu]

Definitely could be the carb, as these things are prone to going bad, but yours I believe is also the older version with not as much electronic crap on it though. I would replace the fuel filter first and go from there, also have you done spark plugs or wires on it, or do they look fine, same with the distributor cap and rotor. Also, it very well just may be the engine characteristics, if its a 2.0 those things were pretty gutless from the get go, let alone 30 years olds

[pennyman1]

The early mikunis were notorious for sluggish performance issues, and leaking into the throat of the carb , causing flooding. Is the choke opening all the way - the thermal wax element choke goes and doesn't open the choke all the way nor does it close all the way, making it hard to start in the cold. If you want it to run, replace it with a weber; I changed Geronimo's back in 1983 and never looked back.

[OCD Boss]

@DroppedMitsu - I have changed the spark plugs, but I have not with wires, cap or rotor. It is running the 2.6, so it should have a little potential to get up and move. I'm not expecting to do 140mph in this thing, but I do want to get it to a point where getting up to 60 isn't a challenge.

@Pennyman1 - Yes, I definitely am making the move to the weber, there are no 2 ways about that. But if you remember in an earlier posting we talked about the weber and you warned me about needing to do the fuel pump at the same time. So that's what I'm waiting for, to have the funds to do the carb, fuel filter, and fuel pump all at the same time. Also I will be having the clutch rebuilt, just because it needs to be done and I would just rather have all the work done all at once so I can have most of the core performance issues worked out. Which then in turn is going to open up the opportunity for cold air intake and exhaust. Then with all that out of the way, I can get to the fun stuff like making her pretty. And actually on that note, what is a fair amount to have work like that done for? I have a guy that is a friend of my gf, but I think he might be over charging, so just wanted a second opinion.

[pennyman1]

Thats a hard one, as I did all my own work to change it over, with help from friends.

[OCD Boss]

Gotcha, fare enough. I just don't have the space mostly to be able to do it myself unfortunately. Otherwise I would prefer TO do it myself. But it is what it is. And unfortunately I need it to be my A to B ride for the moment. So as much as I would love to do everything myself, mechanically I need to just have it done so she is a strong runner.

[OCD Boss]

Alright fellas, I have now replaced the carb, fuel pump, fuel filter, spark plugs, spark plug wires, and ignition control module. The pep has stepped up from 1 - 3,000 rpm, however after 3,000 rpm all power goes out the window. Anybody have any other ideas? It was suggested to try the electric fuel pump and something about the back pressure something (can't think of what it was now). I just remember that it's attached to the Distributor. So next immediate purchases are the ignition coil and distributor cap w/ rotor. Even though I don't think that's going to fix the power issue, I just want to complete the replacement of the electrical. So what else can I do?

1431

[pennyman1]

Put a gauge in the fuel line between the carb and the fuel pump for a pressure measurement. 3-5 is good, although too much or too little pressure will cause problems. Is the vacuum advance hooked up to ported vacuum? Is the cable pulling the throttle all the way open to work both vanes - this is a 2 stage 2 bbl carb, so if it don't pull far enough, the second larger barrel will not open far if at all, and performance will suffer. Also measure vacuum at idle and adjust with mixture screw for max vacuum - run screw all the way in, then turn out until idle smoothes out, then finely adjust for highest vacuum reading. Make sure all bolts on carb, adaptor plates and intake are tight to prevent vacuum leaks. Pull the plugs and check the color of the ceramic around the center electrode- black is rich, white is lean, light tan is good.

[OCD Boss]

So it finally reared it's ugly head and took a turn for the worst..............

I have been noticing that some of the little things the truck has been having more and more troubles with the more I do with her. And then finally, the other day, I went to start my truck after a day at work, and it fires..... I'm warming it up...... and after about 5 minutes of holding the gas down, maintaining 1 - 1.5 rpm, I let off and the motor instantly dies. I start it back up, and yet it dies again the second I let my foot off the gas. I fire it one more time and I start noticing the exhaust (which was rarely colored to begin with) start getting colored and thicker. So I killed it there, and had it towed to a mechanic. The mechanic says their guess is that it blew through the rings since there is "dried oil" splattered on the firewall from the tube that comes from the exhaust.

So now the question is where can I find a full rebuild kit?

[pennyman1]

The exhaust glowing red is a sign of running lean - the "dried oil" did not come from the exhaust unless the head cracked and was dumping oil into the exhaust massively. I assume they were talking about the breather pipe into the top of the exhaust manifold being cracked- it would cause a major exhaust leak and kill your power from the motor. Plug the top of the manifold with a steel plug and start it up again - I bet it will run much better without the massive leak. I'd also find another mechanic - they don't know what they are talking about and are going to cost you a ton of money learning about your truck.