3FE stalling issues (1 Viewer)

[wildsidelife]

Calling all 3fe-heads!

I'm currently fighting an engine gremlin that I can't seem to get to the bottom of and I'm hoping someone on here has learned from past experience and can pass this wisdom on to me.

I'll start by saying I have a 91 80 series with a 3fe. Just over 200k on the odo and love the thing. She's a tank! Attached are a couple pics if you're interested

After running my engine hard (prolonged mountain driving [live in Colorado], hard offroading, mostly prolonged high revs/flooring it) and I come to a stop, the engine comes close to stalling and frequently stalls out if I don't get on the gas again. It putters out, all of the dash lights pop on and bam, dead. I can start the car normally right after it stalls out, but I'd rather figure out the problem than to just deal with it. I'm by no means a mechanic, but I try to do most of the work on my 80 that I can.

To me, I think this problem looks air/fuel ratio related, and that it would be something going on post MAF. I checked the all of the intake for any cracking or old worn out parts where air could maybe get in/out, replaced them, still having the issue. I checked all of the EGR lines in case it was related to that. They're old but none are cracked or leaking at all. I have no dash lights or other leads besides what I've listed. I chucked some BG44K through in to maybe clear up the injectors if that was causing the issue but no dice. A longshot but thought I may as well give it a try. I really don't want to have to pay for a mechanic to fix this and would love to tackle whatever this project entails myself.

Please feel free to ask for more info or clarity if you need, and please help me fellow cruiser-nuts!

 

[jonheld]

UPDATE: I had some cruiser heads take a look at it and after some searching, they stumbled upon the issue. We now know where the issue is, but not yet why:

When taking out a few vacuum lines to check for leaks, they unplugged a connector powering the pump that pushes more air in the exhaust to dilute it in order to pass emissions. After that connector was disconnected, the stalling went away, meaning there is probably leak is somewhere within that air pump system.

Very glad I took it in as I would have never found that myself. I will post pictures of which connector I'm talking about if people are interested. I am now driving around with that connector unplugged, which solves the stalling issue, but I may not pass emissions. I will fix it eventually but it's a bandaid fix for now.

Now that I know the problem, I will investigate further when I have time and diagnose what exactly the issue was coming from. Just thought I'd update in case you all are having a similar issue!

I assume you're referring to the smog pump. There is no "power" to the pump as it is belt driven. The only connection is to the VSV for the pump.
However, the smog pump VSV is only opened in very specific conditions as specified in the FSM.
I have found that there is no issue removing the smog pump. Mine had a York compressor in its place. I was able to easily pass NJ emissions.

 

[wildsidelife]

I assume you're referring to the smog pump. There is no "power" to the pump as it is belt driven. The only connection is to the VSV for the pump.
However, the smog pump VSV is only opened in very specific conditions as specified in the FSM.
I have found that there is no issue removing the smog pump. Mine had a York compressor in its place. I was able to easily pass NJ emissions.

That could very well be the case. Like I said previously, I am no mechanic and just getting into these things so a lot of the EGR system is a mystery to me, but I do know it causes a lot of issues and many people end up just removing the whole thing or going with the bb method. Unfortunately I live in Colorado so my emissions tests are pretty strict, but I dont ming just plugging in the connector to pass and leaving it disconnected otherwise.

Interesting that you say the VSV should only open in certain conditions, since my issue was happening non stop all of the time after a while. It does indeed sound related to the problem I'm having, so I will definitely take your notes into consideration when investigating. I appreciate the input! Going to see what exactly the problem is before I do any part replacement.

Cheers