1987 4runner rough idle on cold start/no power
08-17-2018, 06:10 AM
#1
1987 4runner rough idle on cold start/no power
I started off by searching A LOT of rough idle threads but did not find many answers.
1987 4runner, 22re, manual, with 220k
My CEL is present but the issue is not causing a CEL which isn’t baffling to me.
recently replaced
plugs
wires
rotor/cap
put in a Denso O2 sensor(truck only has 1)
In the last few weeks my truck has developed a problem running super rough at idle. When I start the truck it turns over rather quickly, almost dies, and then climbs up to 1100k and runs fairly well. After about a minute the idle will come down and settle around 800k and the whole truck is a’shakin. The exhaust does not smell particularly rich, nor does it have that acrid lean smell.
The only way to fix the issue is to drive the truck around for a few minutes and the problem goes away. From idle to around 3k the truck is super boggy and then it’s like the power surges in. I drive the truck for 5 min keeping the rpm above 3k and the issue goes away. The idle is pretty smooth after this, at 1000rpm. I set the idle air screw at 1000k for now because otherwise it will go back in to that rough idle if I turn it down even after it’s been warmed up.
If the truck has been sitting off for even 10 minutes after I’ve warmed it up and driven it it’ll start up pretty rough, although it doesn’t take as long to start running well if it it’s warmer than if it’s cold cold.
Truck has plenty of power and runs well once it’s done the morning routine. I’m still getting 20mpg and has plently if power at freeway speeds.
Something else odd that I’ve noticed is then when I replace the spark plugs it ran great and started up smooth no probem with a smooth idle. A couple cold starts later and the problem was back. When I replaced the O2 sensor I unplugged the battery for a bit and hooked it back up. Once again great start and then a few cold starts later it starts rough. It’s almost like when the plugs got replaced or when the battery was unplugged, it gave the ECU new data to work with and the ECU was able to run the truck well for a bit.
Thanks in advance for the help!
Sam
1987 4runner, 22re, manual, with 220k
My CEL is present but the issue is not causing a CEL which isn’t baffling to me.
recently replaced
plugs
wires
rotor/cap
put in a Denso O2 sensor(truck only has 1)
In the last few weeks my truck has developed a problem running super rough at idle. When I start the truck it turns over rather quickly, almost dies, and then climbs up to 1100k and runs fairly well. After about a minute the idle will come down and settle around 800k and the whole truck is a’shakin. The exhaust does not smell particularly rich, nor does it have that acrid lean smell.
The only way to fix the issue is to drive the truck around for a few minutes and the problem goes away. From idle to around 3k the truck is super boggy and then it’s like the power surges in. I drive the truck for 5 min keeping the rpm above 3k and the issue goes away. The idle is pretty smooth after this, at 1000rpm. I set the idle air screw at 1000k for now because otherwise it will go back in to that rough idle if I turn it down even after it’s been warmed up.
If the truck has been sitting off for even 10 minutes after I’ve warmed it up and driven it it’ll start up pretty rough, although it doesn’t take as long to start running well if it it’s warmer than if it’s cold cold.
Truck has plenty of power and runs well once it’s done the morning routine. I’m still getting 20mpg and has plently if power at freeway speeds.
Something else odd that I’ve noticed is then when I replace the spark plugs it ran great and started up smooth no probem with a smooth idle. A couple cold starts later and the problem was back. When I replaced the O2 sensor I unplugged the battery for a bit and hooked it back up. Once again great start and then a few cold starts later it starts rough. It’s almost like when the plugs got replaced or when the battery was unplugged, it gave the ECU new data to work with and the ECU was able to run the truck well for a bit.
Thanks in advance for the help!
Sam
Last edited by Sam Latone; 08-17-2018 at 06:13 AM. Reason: Typo
08-17-2018, 04:46 PM
#2
Can't fix anything while it's throwing codes reliably, but you knew that already I think.
Exactly what trouble code are you getting.
Have you done the "power balance test", pull each plug wire one at a time, to try and identify a problem cylinder?
Checked for vacuum and exhaust leaks?
Inspected the plugs for fouling, wet, carbon buildup ect.
Can't hurt, much, to clean your temp sensors every couple of decades.. (22re have an enrichment program intended to get the engine upto operating temp)
Inspected your accordian hose for cracks..
Base timing is set where?
And on and on... You said you searched and read lots of threads, but didn't answer/address these basic tests.
Exactly what trouble code are you getting.
Have you done the "power balance test", pull each plug wire one at a time, to try and identify a problem cylinder?
Checked for vacuum and exhaust leaks?
Inspected the plugs for fouling, wet, carbon buildup ect.
Can't hurt, much, to clean your temp sensors every couple of decades.. (22re have an enrichment program intended to get the engine upto operating temp)
Inspected your accordian hose for cracks..
Base timing is set where?
And on and on... You said you searched and read lots of threads, but didn't answer/address these basic tests.
08-17-2018, 06:10 PM
#3
Yeah i inspected the wires and plugs when I replaced them yesterday...also the CEL is NOT on. I also have carb cleaned all the vac lines and I don’t have a vacuum leak. The PO deleted the EGR system.
Today I pulled out the TPS and found that it was slow to return to neutral position, It was sticking at almost closed. Replaced the TPS sensor and calibrated it per Frankenyota. Idle is still rough. What would your next move be?
Today I pulled out the TPS and found that it was slow to return to neutral position, It was sticking at almost closed. Replaced the TPS sensor and calibrated it per Frankenyota. Idle is still rough. What would your next move be?
08-17-2018, 07:14 PM
#4
My CEL is present but the issue is not causing a CEL which isn’t baffling to me.
Pics or it didn't happen as the saying goes.
Show us those plugs.
And address the rest of what I said, or not
You want to chase a rabbit down a hole with a blindfold on go ahead and start throwing parts at it. Might as well start with the ignitor module, it's only about 500$ from lce grab a distributor too maybe the bearings shot.
You NEED to identify if it is a consistent no fire on a single cylinder (the power balance test), a consistant misfire on a particular cylinder (typically going to show up on the plug by color or crud), or a random misfire hopping cylinders (air/fuel/spark ratio and timing).
08-18-2018, 02:54 PM
#5
What I mean by CEL present is that the bulb is there and flashes and it should when the truck starts. After the truck starts the light turns off. I’ve had trucks in the past where folks removed the bulb.
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