AMC Eagle Den Forum

The Mighty 258 => Engine Electrical Systems. => Topic started by: kajsdf on March 27, 2012, 11:05:14 AM

Title: difficult to start when hot
Post by: kajsdf on March 27, 2012, 11:05:14 AM
i have a new issue i am having some trouble tracking down...with the carter, my eagle was occasionally difficult to start.  it has improved somewhat with the install of the 2100, but not completely.

car starts great when cold -- absolutely no problems.  if it was cold outside with the carter, i wouldn't even be able to get it to start.

when engine is close to operating temperature, starting usually requires holding throttle wide open, then it coughs and sputters a bit, then stabilizes.  i assume it is choking on excess fuel, but i do not know for sure.

emissions stuff is not hooked up, no vacuum leaks i can find. egr does not leak.  spark plugs are good, plug wires are new-ish (within last few months from tfi/miu) along with coil.

could it be the ignition box going out?  i'm a little stumped on this one.
Title: Re: difficult to start when hot
Post by: GRONK on March 27, 2012, 11:16:06 AM
Could be base timing, could also be resistance to the coil.  Everyone, please chme in if Im incorrect, but the running voltage to te stock coil is 6-9V, but on start up, the coil gets a ful 12V (bypassing the main resistor wire) 

Thinking more about it, could be a slight air leak in the fuel line and or pressure building in tank when hot.

Just throwing some ideas out there.

Is the choke properly opening when at operating temp?
Title: Re: difficult to start when hot
Post by: kajsdf on March 27, 2012, 12:07:13 PM
choke works great at operating temp

if it was timing, am i too far advanced?

forgot to include in original post, but i do have to work the throttle a bit to keep it from dying until everything evens out
Title: Re: difficult to start when hot
Post by: GRONK on March 27, 2012, 12:25:27 PM
What is your elevation and what is your base timing set at? (at 650 RPM)  Sounds like you might be too far retarded.
Title: Re: difficult to start when hot
Post by: mudkicker715 on March 27, 2012, 01:09:48 PM
To eliminate the tank pressure loosen or take the cap off the tank for a trial
Title: Re: difficult to start when hot
Post by: kajsdf on March 27, 2012, 06:33:18 PM
12* , 4368 elevation
Title: Re: difficult to start when hot
Post by: eaglefreek on March 27, 2012, 10:21:11 PM
Mine does the same thing. When it's warm outside and I stop to go into a store for a few minutes. I have to hold the throttle to the floor and it will sputter a bit before clearing up. I can smell fuel from about 10 feet away after turning my car off. I've pulled the air cleaner and have seen fuel percolating into the manifold when the engine is turned off. I was going to make a heat shield to put between the carb and manifold, but keep telling myself I'm going to do the EFI swap soon and not to worry about it. This will be my third summer dealing with it. I think I will have to do one or the other.
Title: Re: difficult to start when hot
Post by: carnuck on March 28, 2012, 04:24:02 AM
See if the line going into the carb is loose. They can "swing" downwards from the weight of the fuel filter and raise the float level, flooding the car after shutdown.
Title: Re: difficult to start when hot
Post by: rohnk on March 28, 2012, 09:48:26 AM
Sounds like a bit of a stretch, but what about vapor lock? Maybe try loosening the gas cap and see if it makes the soda can sound when you open it.
Title: Re: difficult to start when hot
Post by: kajsdf on April 05, 2012, 07:38:05 PM
i took another look today, and it is the same problem eaglefreek has. i see fuel dripping in one one side, closest to the valve cover. it is the generic 1 in 1 out clear filter from napa - is the angle it sits at what is causing this? the problem is more prevalent on hot days so i am not certain i really understand what exactly is happening
Title: Re: difficult to start when hot
Post by: JayRamb on April 05, 2012, 08:28:15 PM
My problem was my ICM. Replaced that and solved everything.
Title: Re: difficult to start when hot
Post by: eaglefreek on April 05, 2012, 10:02:46 PM
i took another look today, and it is the same problem eaglefreek has. i see fuel dripping in one one side, closest to the valve cover. it is the generic 1 in 1 out clear filter from napa - is the angle it sits at what is causing this? the problem is more prevalent on hot days so i am not certain i really understand what exactly is happening

Hmm. I have the one outlet filter also. I wonder if that has something to do with it.
Title: Re: difficult to start when hot
Post by: kajsdf on April 05, 2012, 10:54:17 PM
i switched to the oem screw in type and it seems to be starting better. ill drive around tomorrow to test it out.
Title: Re: difficult to start when hot
Post by: rohnk on April 06, 2012, 07:33:20 AM
That makes sense, no place for the extra pressure to go once the engine is shut off. On the OEM type, the third plug for fuel return to the tank depressurizes the line between the pump and carb.
Title: Re: difficult to start when hot
Post by: Jurjen on April 06, 2012, 09:42:43 AM
I had that problem with the 1 in 1 out filter too. After switching off the engine there is too much pressure inthe line causing the carb to flood.
Problem solved after I reinstalled the 3-way filter and hooked up the return line again.
Title: Re: difficult to start when hot
Post by: kajsdf on April 09, 2012, 09:27:06 AM
jurjen, how did you set up the return line? i noticed the carter had a funny insert on the connector, and i am unsure of its purpose.
Title: Re: difficult to start when hot
Post by: Jurjen on April 09, 2012, 03:45:49 PM
The return line is on the filter, you will find the fuel return line itself somewhere near the shock tower on drivers side.
The return line itself has a non-return valve that is opening from filter to tank.
More information in this thread:
http://forums.amceaglenest.com/index.php?topic=36284.0
Title: Re: difficult to start when hot
Post by: shanebo on April 10, 2012, 01:36:58 AM
I've had cars do that before too...they start in the coldest weather but try to start it after driving an hour and forget about it. It almost acted flooded....I could smell heavy gas fumes when they did it. One of em turned out to be the wrong gas cap and it wasn't
Venting properly.
Title: Re: difficult to start when hot
Post by: kajsdf on April 10, 2012, 01:05:29 PM
that thread was quite helpful and it sounds like it's going to work -- however nowhere in town stocks a 1/4 fuel check valve. i found one on the 'bay for 20ish shipped...if it works, that is well worth it to me, but do you have any other part suggestions?
Title: Re: difficult to start when hot
Post by: Jurjen on April 11, 2012, 01:18:34 PM
Nope, just a three way filter, a check valve and fuel hose to hook-up the return line.
Check the rubber hose near the tank too, it may be old and brittle.
Title: Re: difficult to start when hot
Post by: kajsdf on April 11, 2012, 02:58:43 PM
Do you have a part number or possible location for the check valve? nobody in town stocks them but i found one on the auction site for about 20 - is that reasonable?
Title: Re: difficult to start when hot
Post by: Jurjen on April 11, 2012, 03:55:49 PM
As you can see I'm located in Europe.
The valve I have, will cost $16 on the famous auction site in the US.
The famous auction site in the UK has them for 4GBP!
Normally car parts are much cheaper in the US.
Title: Re: difficult to start when hot
Post by: kajsdf on April 11, 2012, 04:29:02 PM
completely forgot you were in europe - even though i knew that already.  ;D

the picture in the posting looked exactly the same as yours, so i figured that was it. 

thanks a bunch...you are a treasure trove of valuable eagle knowledge...and i am sure much else...
Title: Re: difficult to start when hot
Post by: Jurjen on April 11, 2012, 04:48:42 PM
Quote
completely forgot you were in europe


I take that as compliment  ;D
Title: Re: difficult to start when hot
Post by: kajsdf on April 24, 2012, 04:51:36 PM
the results are in -- the check valve alone did not solve the problem.  when getting gas the other day, i got the "soda can" hissing sound mentioned by mudkicker and rohnk. it was not present before the return line was re-instated...

which leads me to believe i have a multi-part problem...previously, i think the tank was venting thru the return line somehow, but there was still too much pressure which flooded the carb.  now, the return line doesn't allow this which gives the excess pressure at the cap.  is this due to the cap not venting properly?
Title: Re: difficult to start when hot
Post by: mudkicker715 on April 24, 2012, 04:58:10 PM
So is hissing vacuum or pressure¿
Title: Re: difficult to start when hot
Post by: kajsdf on April 24, 2012, 05:14:56 PM
definitely pressure - if the cap wasn't screwed on, it would blow itself off...but......i think i just solved the problem....


apparently when i installed the 2100 i just set aside the return hose because it was crimped to the return line and i intended to deal with it later.  when i reinstalled the return line, i was hooked up to the smaller of the two lines going to the tank -- apparently one of those is a vent...i think you can see where this is going...i didn't even think about the other line because i had the hose tucked away somewhere so i thought it was attached to something else.

frankly i'm ashamed.....
Title: Re: difficult to start when hot
Post by: kajsdf on April 24, 2012, 09:25:10 PM
it still seems to have trouble starting up but it doesn't seem to be as bad - i rigged up a hose from the vent line out the grill as a temporary measure to get everything non-vapor out of the line...i know it's working because the hose reeks of gas, but it probably just isn't empty yet. no more hissing from the cap, though...