78 1800 Stalling when warm and carb's a dogs breakfast

[Ggirl]

Hi folks,

I have a similar problem that its seems a few have here with the engine stalling after its warmed up, wait 10minutes engine starts nice and I can drive for another 10-15minutes. From cold start to the first stall I get about 20-25 minutes of drive time before it acts up. I am going to test the fuel pressure (mechanical pump) and see if that it the cause. Also I will verify the ignition coil is operating properly. I the meantime I took a look at the carb (32ADFA) and it seems that someone started pulling and plugging. No doubt this is causing issues.

I am not too familair with carbs. Here is a couple of pictures that I snapped.




I compared the carb to this diagram: http://www.piercemanifolds.com/v/vspfil ... d_ADFA.gif

The part thats wrapped in black tape. I am thinking that that is #76: ICU Solenoid. Could this be resoponsible for the stalling?
Can you folks see the other ports that have been capped and help me regonize what they're for and where they should be connected to? Or if they are ok the way they are capped?

Thanks, look forward to your expertise.

[mobigly73]

It's probably the ICU it needs a wire plugged into it or it will stall. I'm not positive but the choke is keeping it running until it comes up to temp then it stalls. There should be a wire with a blade connector somewhere near the fender well area. maybe all you need is a replacement switch and your all set.

[DocGraphics]

The wire that should be hooked to the idle solenoid is a switched 12V that has power when the key is on & opens the idle circuit.
On my 78 it is 2 wires hooked together at the plug in, brown/red & pinkish

Here is the wire hooked to the electric choke on my 32/36 upgrade.



This connection to the idle solenoid needs to be hooked up or won't have fuel at idle unless idle is turned up high enough to idle off the run circuit in the carb (bad/wrong) or choke is engaged (also running off run circuit in carb)

When this wire is hooked up the solenoid should click when key is switched on or you can test by unhooking it & rehooking it with the key on & it should click.
The idle jet could also be clogged, pull out that solenoid & clean the jet attached & spray carb cleaner thru the hole it came out of.

[So Cal Mark]

yep, the solenoid needs switched ign power. The port that is capped used to supply the egr thermovalve with vacuum. The thermovalve is on the inside of the carb with a looped hose on it. It's just fine the way it is

[Ggirl]

Thanks for the feedback. New solenoid ordered and I will post an update after installation.

[Ggirl]

The new ICU Soleniod has been installed. I haven't really been able to test drive, because without adjusting any of the existing settings the car would immediately stall. It needed a little throttle to get started and would quit right away. Only after having the large ajustment screw on the bottom of the carb fully turned in would the car stay idling. However, it would really hestitate or sputter and almost stall when lightly applying the throttle. It is also important to note that the tempurature got to about 210 before I shut it off, before it would almost always stall at 190, I suspect this is the treshold for the bimetallic coil. So, the soleniod is doing its job.

I sprayed the carb with carb cleaner, including the idle jet. I noticed that when I applied the throttle the fuel entering the carb was "drippy", for lack of better words. Is this supposed to be a "spray" or is this normal?

Here's a picture to help clarify:


Also here is a picture with the new soleniod installed (12.25v ignition confirmed)


I suspect that the settings were really off in order to keep the car running with the icu solenoid disfunctional. I am wondering if there is a 1 - 2 - 3 guide to setting the carb to run properly?

[tartan18]

Here is a great guide to dial in your carb.

http://www.redlineweber.com/html/Tech/c ... _best_.htm

[Ggirl]

Thank you for the guide. I have been able to stabilize the idle, but was a little lost because the terminology from the guide and the manuals are not consistent. Consequently, the car is running really rich. Can I please get some clarification on the adjustment screws and their function? I think I have this correct, but please let me know if I am messed up.

[tartan18]

Here is another great resource for dialing in your carb. See the last page for the locations of both the idle and mixture screws on the DFEV. The functions of the adjustment screws are as their names imply ... to adjust the idle speed turn this one in to lower the rpm of the engine - out to increase the engine speed. Mixture controls how rich or lean. Turn in to lean or out to increase mixture. As the guide says, set the initial mixture to two full turns from all the way in (not too tight - just to where the screw bottoms out). Back the idle set screw to that it barely touches. After setting the mixture and idle screws you can fine tune the idle set screw.

I have found using a vacuum gauge to set both mixture and idle to be the best method vs. trying to do it by ear. You want the highest vacuum reading on the gauge as you turn the mixture screw slowly in and then out.

http://www.webercarbsdirect.com/v/vspfi ... 0Guide.pdf

Hope this helps.

[So Cal Mark]

if the car is running extremely rich, you probably need more than an adjustment. Sinking float or misadjusted float comes to mind as a common cause

[Ggirl]

I have re-adjusted the mixer and the idle speed, seems better now. There is still a strong odor but the car does burn a fair amount of oil so can't really avoid that (apologies to those behind me in traffic).

When removing the air cleaner lid I notice quite alot of oil on the onside of the air cleaner lid, checking the crankcase vapour line I notice a fair amount of oil coating the walls as well. Is this normal, could this be adding to the smoke from the exhaust?

I also, check the compression of the cylinders, 1-110psi, 2-115psi, 3-117 psi, 4-115psi. (engine warm). The gauge wasnt super accurate but I think these are a little low, but I plan on pulling the engine and rebuilding it in the winter months... I get 7 of them.

I also am pretty sure the fan temp switch is defunctional because I got the temp pretty high about 220 and no fan, but it does work, I bumped it with 12v directly.

Thanks again for the help!

[mPedro08]

I also, check the compression of the cylinders, 1-110psi, 2-115psi, 3-117 psi, 4-115psi. (engine warm). The gauge wasnt super accurate but I think these are a little low, but I plan on pulling the engine and rebuilding it in the winter months... I get 7 of them.

I also am pretty sure the fan temp switch is defunctional because I got the temp pretty high about 220 and no fan, but it does work, I bumped it with 12v directly.

Thanks again for the help!

I think you may want to do a leakdown test to see if the rings are allowing compression gasses into the crank case. This would cause blow by and lead to excessive oil in the air cleaner housing. Probably right about the switch but could also be a frayed or bad wire.

[Ggirl]

I went for a test drive on the highway. The car ran well and was responsive at 100km/hr apprx 3600rpm. After 35km I turned around and as I was accelerating back to highway speed I got alot of sputtering. Then after about 10km I had to slow down a little for traffic and as I went to accelerate the car totally stalled. After that it wouldnt start. I did al bit of diagnostics, got fuel, no spark at the sprak plug. No spark at the coil wire. I confirmed with a mulitmeter that the coil was getting 12v from the battery. I also put the multimeter to the plug outlet on the coil and got 11.46v. Is this right? I thought it should be way higher. I am just realising that I probably needed to change the settings on the meter. Also, thinking that I should check the coil wire for continuity. Another comment the coil was hot! Dangerous to touch hot, again is this normal?

In general can coils act this way?

[Ggirl]

I replaced the coil and no I am back in action.