My 4Runner has been acting weird lately it’s running ok then I take it out and it has like no power whatsoever when I’m trying to get up to speed it does slowly accelerate but not as much as before and after that stutter in acceleration if I try to slow down to stop the engine rpm drops to below 500 and stalls the engine occasionally. If I restart the engine it drives fine for a while and then does it again. I just got another engine put in it so I’m going to be doing maintenance like plugs what else should I look for. The fuel filter is 2 years old. Could a timing belt on its way out cause this? Any help appreciated
No power when accelerating and tries to shut off after slowing down
- Thread starter Sir_LR
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Twisted Sid
Member
No codes?
I'd start with vacuum leak testing
I'd start with vacuum leak testing
spartacus
Senior Member
What year. How many miles on the motor? Any codes? Plugs wires. Clean maf, clean throttle body and timing belt might help.
Edit: A new Pcv valve and tps sensor could help.
Last edited:
Hungryhawk
Member
An idea to see what result reveals.
I assume you are in drive"D". Does it act same in S4?
Have you turned off VSC and see if any difference?
My 2cents
I assume you are in drive"D". Does it act same in S4?
Have you turned off VSC and see if any difference?
My 2cents
A stretched timing belt would not be resolved by restarting. Did this start occurring right after the motor swap? If so it may be a sensor related issue caused by the computer receiving the wrong signsl after calling for sensor input. When input is received it goes wonky then on restart it happens all over again. If it's this scenario codes should be present. More information is needed.
My truck does not have s4 or vsc
It’s been over a year since installing the engine I just don’t know what maintenance history it has. I’m hoping to do some simple maintenance and fix it like plugs wires timing belt and clean the iac. Could this be caused by a fuel pump not sending enough fuel occasionally or is that not possible. Thanks for all the input
There’s no codes showing at all
After shutting it off and starting sometimes it wouldn't even come back like it did yesterday but occasionally it does. I got the IAC gasket on order and I'm going to clean that out first and go from there with plugs and timing belt. Ill test fuel pump pressure while I'm at it, will report back with any findings
TheDurk
Elite Member
The runs fine and then goes wimp is characteristic of a defect that is linked to the switch over from open loop to closed loop operation. In my case, a TB body clean was what it took, but it could br AF, MAF, or anything in that loop. Definitely not fuel pump, timing belt or anything else not in that loop.
Update again: Problem is back… now without the stalling issue but sometimes it won’t accelerate at all and has popping sounds coming from the right side of engine. Help please! Next up is plugs and diagnosing spark and fuel. Since I’ve ruled air out completely. Any ideas would help a lot.
T4R2014
Elite Member
I think you had two problems originally. Stalling upon deceleration is usually a gummed up TB/IAC on these. Probably needs plugs and wires now. I'll go ahead and say it will run even better with three new Denso coils. Also look for cracks in rubber hoses causing vacuum leaks.
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