Iron Duke Problems / Tuning

[truk820]

Hi all,

Hope everyone’s having fun dealing with the cold / snow!

Last night was the moment of truth: I tried to start the engine after a few months of my rebuild (FYI I’m running an Iron Duke). Checked fluid levels, put a few drops of gas in the carb and she fired up! Well, kind of.

To backtrack a bit, before I started the rebuild I had it running but only took it around the block a few times. Between running it in the garage and the ‘around the block’ spins I’d say it ran for an hour or so before everything came apart. It always ran rough.

Anyway, when I turned the key the first time it tried to turn over and didn’t fire up. I waited a minute or two and tried again. This time I only heard clicks, then nothing. I waited another 3-5 minutes and tried it again – no problem firing up. I remember this problem before: the first time or two I’d try to start it I’d hear the clicking like the battery was dead or something else was shot, only to have it fire up on the next attempt a few minutes later. To rule out the battery I charged and checked it before connecting – it’s holding 80% of a full charge. Also, after it started I had to continually give it gas. If I let it idle it’d die almost immediately. I don’t have a tach so I’m not sure what it was running at.

Additionally, I’m running the Rochester 2SE carb (pics here: , that has some lines plugged with what looks like SheetRock screws). I don’t have to go through emissions and the charcoal canister is disconnected.

Now, a few questions:

1. What do you think could cause the odd starting sequence of clicking / nothingness then starting up? Any things I should try?
2. How do I fix the idling problem? I’m not a mechanic and this is my first foray into the engine world (like everything else on this CJ!)
3. I’m going to change the plugs, wires, cap and rotor. Anything else you guys recommend to tune an Iron Duke? I found this thread (http://www.jeep-cj.com/forums/f2/4-cylinder-gm-iron-duke-power-question-11501/) and it was helpful. Just want to cover all my bases.

 

[Torxhead]

The clicking sound is probably the starter relay, this could be from a weak connection,weak battery or worn out starter relay. The relay can be checked by bypassing it, as I recall that would be by running a jumper between the "S" and "I" terminals, I use one of those push button attachments to check that. Your running problem sounds like a fuel related issue, like maybe poor fuel pump pressure or low float bowl. Or is it runnung too rich?

 

[truk820]

It doesn't seem to be running rich, I guess I'll read up on how to tune the carb though. Fingers crossed it isn't too difficult.

Re: the starter relay, how tough is it to replace? I did a quick search on Autozone and it doesn't look too expensive.

 

[Torxhead]

Replacing a starter relay is a simple parts swap if that is your problem. The more important part is making sure the electrical connections are good. Your float bowl level could be the issue, did you install a new fuel pump?

 

[truk820]

Nope, never installed a new fuel pump. I'd ruled that out because once it fired up it'd run continually although the problem of me having to continually feed it gas may indicate my fuel pressure could be off. Is that a common problem?

 

[Torxhead]

You should know if you are even getting enough gas to the pump, as old as the vehicle is anything could be wrong with it. I would begin with making sure there is enough fuel in the float bowl and is the float bowl level set correctly. Then make sure the fuel pump is working correctly, This is best done with a fuel pressure gauge.

 

[gert]

unfortunately without being there it is hard to tell for sure but you need to get the basics down, check/set correct ignition timing, check float installed height, set carb idle screws, check/clean trash in carb/ fuel lines/ tank check for vacuum leaks

 

[truk820]

Yeah...this is what I was afraid of.

Of everything you've listed, how would you order it on the level-of difficulty scale, from easiest/cheapest to toughest/most expensive?