Stumped on what is causing stalling/rough idles

Hi everyone,

Last month I bought a 1996 Tacoma extracab 2.4L that had a handful of issues and couldn't go down a block without stalling. So far I've changed the IAC, fuel filter, spark plugs, and MAF and although it runs so much better than before, it still has issues such as starting after it's heated up, stalling on right hand turns or heavy bumps, slow acceleration at times, and random rough idling from misfires. A friend had me check the ignition rotor and found that it had lots of leeway, on the part it fits to, and when we replaced it with one that didn't have much leeway the truck started in way better conditions. The engine didn't shake when turned to the right anymore, rough idling/misfires, and slow acceleration went away. That was until we drove it for a bit, then the issues came back and maybe even slight worse. I'm at my last bit of sanity and would like some ideas on what the main issue could be.

 

Is the truck displaying the check engine light when this happens? It should be with something that drastic. The best place to start will be looking at the exact code the truck is throwing to narrow things down.

 

P0171 I believe, states a lean condition and is why I replaced the MAF and fuel filter.

 

That is good to know.
The next two things to check would be fuel pressure and the upstream O2 sensor.

 

I apologize as I forgot to mention that I also replaced both upstream and downstream sensors. Something to add is yesterday that I took off the distributor cap and took off the ignition rotor and put it back on and it fixed the issues again for about 30 minutes then after enough bumps it started having issues again. I'm not really sure why it fixed it temporarily doing that.

 

You need 3 things for an internal combustion engine to function - spark, fuel, and compression. Check each of those. I suspect you'll find a problem with one of them.

From the description, the fuel pump and/or filter sounds suspect, so I'd probably start with a fuel pressure check, as suggested above.

 

How many miles? If the 2rz is anything like the 3rz then the valves need adjustment every 90K miles or so. Failure to do so can result in burnt valves and idle issues.

 

The distributors on these are known to be an intermittant problem and they arnt cheap. If the shaft that the rotor sits on is loose your distributor is worn out.

 

On that older vehicle there may be a (camshaft) sensor pickup in the distributor. If the dist shaft is loose and wobbling around it may be losing its signal to the pcm resulting in a stall

The p0171 could be caused by a intake vacuum leak somewhere

 

miles?

https://youtu.be/UKB9iX2SQtM

 

I did a smoke vacuum leak test and it showed the EGR was only leaking so I replaced it. Also a friend said that if it was a fuel pump issue, I wouldn't be able to go on the highway which I'm able to. I will look into the distributor shaft issue later today.

 

sorry that vid is WAY general

but i read that if rotor/cap removed and wiggle the shaft(with dizzy still in the head)
if there is noticeable 'slop/play' in the shaft...that might be issue

especially if issue comes and goes(intermittent)

 

Also
This was (what I expected) was original FF
Yuck

 

looks like after that
all possible causes have been mentioned


i did end up sending my injectors off to Motorwest, but i did not have any symptoms you have
(just hot no start issue)
GL
keep everyone posted