Random Stalling when at Running Temp

[wiley-moeracing]

Good, now your making progress. check float level in carb, is the very thick heat spacer under the carb, is the fuel line resting on a very hot part of the engine? Here in Arizona I always run a electric pump just for the issues your having.

[Chadryan]

Update: No stall on the way to work! Considering it stalled 3 times on my way home last night, I would say that is an improvement.


On my way home last night when it stalled the 3rd time it really didn't want to start back up. I pulled the fuel line on the pump side of the filter and it was bone dry. No gas. So, I assumed there was either a blockage or a bad pump. Since the pump is fairly new and seemed to be working until the car stalled, I started looking for any potential blockage. Nothing notable came out of the lines when I blew them out. I am thinking that the clogged filter on the sending unit is my main culprit.

check float level in carb, is the very thick heat spacer under the carb, is the fuel line resting on a very hot part of the engine?

I will check the float level. This is something I have read a lot about and have been meaning to do. I have a new phenolic spacer from BJ's under the carb because the one that was on it when I bought the truck was cracked. The fuel line doesn't appear to be too close to the engine anywhere but I am going to wrap the hard line above the pump with some insulating tape just in case.

Anyway. see if enrichening the idle mix helps. If turning the idle mix screws does not effect the idle - then almost certainly the idle passages are gunked up.

I am going to dial the idle mixture screws back in tonight. I have done it a few times as I have been working on the truck and it always seems to help a little. I have not had the carb rebuilt or cleaned. That is probably going to need to be on the list soon.

The pick up tube in the tank should have a pretty big meshlike filter on it (aka sock).

I am familiar with what you are talking about. The original one I took out had one on it. However, the replacement sending unit form the auto parts store has a much smaller plastic filter on the bottom of it. I should have taken a picture of it when I had it out last night. It is this unit: https://shop.advanceautoparts.com/p/...l+sending+unit


I understand that this is shorter than the stock sock. I never let the jeep get close to empty.

[Gadzooks2]

It may sound weird but try taking off the gas cap. The vent may be plugged pulling a vacuum on the tank. Fixed my lawnmower that way once..

[acct21]

Had that same issue last year. Tank vents eventually plug (or soft lines from the vents to the charcoal canister collapse), and my tank was building pressure. Really hard to start (think it was from the return line back-pressurizing the feed from the mechanical pump; it was essentially blowing the fuel back into the tank as it sat). Didn't really have stalling issues, but then the tank started leaking out of the vent seals when the tank was full, so I had to pull it all apart and change everything out. New vents and seals solved it all.

[OldmanWag]

Fuel Tank

Drop the coffin fuel tank and basically hose it out completely. You'll find crap in there that will shock you. Do it on a Friday and give the tank the weekend to dry out. Also pick up a couple of cans of black flat rustoleum. Good idea to spray the coffin.

[joe]

x2
The wires can break down internally from decades of flexing.
The "wiggle" test can sometimes replicate the issue.
If testing and stalls a quick ohm reading of the pickup will show infinite resistance(usually).

Pickup assembly is cheap & easy to replace. Can be done w/o removal of the distributor.

X3 Before buying parts and guessing, check the wires going in the dist. They can/will get brittle inside the wire sheath or chaff on the dist body and short out occasionally .
Does your 87 have the goofy plastic horseshoe coil connector? That can be an intermittent loss of spark.

[babywag]

yep the horseshoe connector on every one I have owned needed replacement.

far as fuel issue just because a part is new doesn't mean it cannot be bad.
aftermarket parts are not great these days. many are poor quality offshore stuff.
a very small debris chunk on inlet side can make a pump nonop.
always best to install a clear plastic filter on pump inlet