2.5L 4cyl Starting problems

[Eric 3.7LX Alpha 1]

Re: 2.5L 4cyl Starting problems

Glad to hear!!!

 

[ngoodart]

Re: 2.5L 4cyl Starting problems

Evening all,
So Today was spent washing waxing and refreshing the neglected gelcoat. After I got that taken care of I got back to getting the motor tuned up. So here is my issue, I am having some difficulty getting the motor to idle below 2k RPM. The book says that it should be much lower then that. In Gear Idle RPM is supposed to be 5-800 rpm. I have played with the idle adjustment on the carb, re-adujsted timing, and repeat. I was able to get it down to around 2k on the dash tach...I know not the most accurate... from the initial setting of over 3500 Any advice on getting the RPM's down to where they should be? also when I give it some throttle and rev up a little 4-4500 rpm it dies, and will re-start after pumping the throttle a few times and will go right back up to idling at 25-2700 rpm... I walk the timing advance and idle adjustment back down....hit the throttle and it stalls... This is all being done in the driveway on muffs... with the water on full blast. The temp is a little slow to come up above 130 and the oil pressure gauge is reading normal. 35-40PSI. Thanks for the help I appreciate it.
Any Ideas?

 

[Don S]

Re: 2.5L 4cyl Starting problems

Disconnect the throttle cable from the carb linkage and see if it slows down. You may have to lightly push the linkage to the idle position.

 

[ngoodart]

Re: 2.5L 4cyl Starting problems

I have it disconnected an the throttle is at the idle stop. The idle stop screw is set almost all the way out. If I back it off any further the screw will fall out.

 

[ngoodart]

Re: 2.5L 4cyl Starting problems

Don, Eroc, anyone, any Ideas?

 

[ngoodart]

Re: 2.5L 4cyl Starting problems

Sorry fat fingers this early Eric*

 

[ngoodart]

Re: 2.5L 4cyl Starting problems

Thoughts? anyone? This just doesn't make any sense.

 

[Failproof]

Re: 2.5L 4cyl Starting problems

Sounds like a carb issue. Float level, fuel bypassing and dumping into intake, air leak, carb leaking. To much fuel pressure, Also could be inacurte tach. Does it sound like 2700 rpm?

 

[ngoodart]

Re: 2.5L 4cyl Starting problems

Guess I'll be pulling the carb off tonight....:facepalm: didn't want to do that.... Does anyone have an pic of what the distrubutor/spark plug wires should be? my new cap isn't marked and I was going off of how it was when I first started. I know what the firing order is by the book I'm just not sure of the locations on the dist. didn't know if that would affect my problem...

 

[Eric 3.7LX Alpha 1]

Re: 2.5L 4cyl Starting problems

Guess I'll be pulling the carb off tonight....:facepalm: didn't want to do that.... Does anyone have an pic of what the distrubutor/spark plug wires should be? my new cap isn't marked and I was going off of how it was when I first started. I know what the firing order is by the book I'm just not sure of the locations on the dist. didn't know if that would affect my problem...

Mark that dizzy cap where #1 is. Literally draw a #1 on it near the post so you know which one it is. (you could do all #'s if you even wanted to, wouldn't hurt a thing. If it is running good ...it is correct.

I have never had the problem not getting the idle down to spec, so I can't help you with what's wrong on it. Does it sound like it's idling or racing faster than idle? maybe the tach is off?

As long as you know where #1 is, the firing order and the rotation of the rotor, your good to go as far as removing wires off it. The thing is, there is no Book location of #1. If someone pulled the distributor out at any point in time in the past. They may have set a different spot as #1 so We can't tell you were it is.

 

[ngoodart]

Re: 2.5L 4cyl Starting problems

Ok thanks,
So If I understand the book correctly when the timing mark on the flywheel is in the timing window then the rotor on the dissy should be pointing to cyl #1 correct?
With the way the spark plug wires are hooked up currently its pointed to #4 with a firing order of 1-3-4-2 starting from the front of the block (bow side) If I look at it from the stern of the motor the rotor would point to #1
Im confused. I will leave the configuration the way that it is and just keep trying to get it dailed in then, I just am concerned that with the RPMs the way that they are if I try and put it in gear that it will damage the out drive at those RPMs. It does sound like a good moderatley fast idle. Any other suggestions?

 

[ngoodart]

Re: 2.5L 4cyl Starting problems

Added some Pics of what I am seeing, The rotor in the dissy is pointed to what makes ense to me to be Cyl #4 and the timining mark is showing 10 BTDC ish Unless I am looking at the motor backwards then it would be Cyl #1 Im Confused

 

[Jimmy9999]

Re: 2.5L 4cyl Starting problems

I am totally new to boats, but have lots of experience with engines.

If it is running smoothly, then the plug wires are connected in the right order. Like someone mentioned, if the distributor has been out of the engine and put back in with the rotor pointing in any random spot - it doesn't really matter. as long as that spot lines up with the plug wire going to number one when the timing marks are lined up.

Also, the timing marks on the crank will go around twice for one revolution of the distributor, you could be looking at the wrong stroke on cylinder number one.

You mentioned the throttle is "on" the idle screw and the screw is adjusted almost all the way. A high idle in this condition is usually due to a vacuum leak. Even a small leak that is hard to hear will drive the idle up. Check all your hoses and look for anything that is disconnected.

Jeff

 

[ngoodart]

Re: 2.5L 4cyl Starting problems

Thanks for the info Jeff, That makes a whole lot more sense. I was going to pull the carb off last night but didn't get around to it. Will post agian when I get it figured out. My parts for my lower drive will be here today so I'm going to be finishing that part up. Then I will pull the carb and start going through it.
My mechanic buddy believes it is in the carb as well, probably a partially or fully plugged idle passage not letting the fuel flow into the carb for the low speed side. When I pump the accelerator pump I can see clearly 2good streams of fuel squirting out into the venturis So we will see. Could be the float too he said. just going to have to take it apart and see.... Thanks for the help guys I appreciate it.