Motor struggling once warmed up after top end rebuild
#1
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Location: Nebraska
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Motor struggling once warmed up after top end rebuild
Well I just finished doing a top end rebuild on my 88 4runner after snapping the timing chain. The motor had nearly all items replaced that could be on it, including timing chain, water pump, oil pump, new valves and such.... as well as all new ignition items inluding the coil. The motor its self is not the normal 88 22re that came with it, the last owner put in a older 22r for some reason but left the fuel injection on it (this is the older type of motor with the dished pistons and spherical head). .
Now, on to my problem.... the truck runs GREAT and makes good power when it first starts up and drives for about ~1 block until it gets warmed up. However, once it is warmed up it is like it looses all power and I can hardly get it to go 5mph as it boggs HORRIBLY when i give it much throttle. I'm somewhat at a loss as to what it is but am thinking of a couple possibilities
-Timing might be off... it was set at ~10* when i set it (not sure if it was fully warmed up tho)
-Vacuum lines aren't for sure routed as per factory specs.... but no leaks
-O2 sensor is throwing a code as its bad... HOWEVER it didnt cause any issues before the timing chain let go and needed a rebuild, it actually drove great.
-MAF could be bad? A bit of water got into the maf (~5oz at most)
Otherwise I'm at a loss... I get great spark, compression is perfect, no vacuum leaks, no fuel leaks, good fuel pressure.
Any ideas?
Now, on to my problem.... the truck runs GREAT and makes good power when it first starts up and drives for about ~1 block until it gets warmed up. However, once it is warmed up it is like it looses all power and I can hardly get it to go 5mph as it boggs HORRIBLY when i give it much throttle. I'm somewhat at a loss as to what it is but am thinking of a couple possibilities
-Timing might be off... it was set at ~10* when i set it (not sure if it was fully warmed up tho)
-Vacuum lines aren't for sure routed as per factory specs.... but no leaks
-O2 sensor is throwing a code as its bad... HOWEVER it didnt cause any issues before the timing chain let go and needed a rebuild, it actually drove great.
-MAF could be bad? A bit of water got into the maf (~5oz at most)
Otherwise I'm at a loss... I get great spark, compression is perfect, no vacuum leaks, no fuel leaks, good fuel pressure.
Any ideas?
#2
Registered User
All three things that you listed can cause the problems your having, the timing should be set at 5 degrees, if the 02 sensor is bad that also can cause problems because the computer uses it to set the air fuel ratio when the engine warms up, and miss routed vacuum lines can also cause a miss or certain things to not operate properly. You need to get all of this sorted out for you truck to run properly, otherwise it won`t.
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