0 Members and 1 Guest are viewing this topic.
Silly question, but is there any chance your catalytic converter is plugged, or exhaust system smashed flat enough to cause an obstruction? There are ways to check for excessive backpressure without too much effort, such as using an infrared thermometer. If it's way hotter before the cat than after, the cat is probably plugged.Anything silly in the intake tract? I've seen nests built in airboxes before. Not common, but something to check.Any chance there are air pockets in coolant?Vacuum lines all plugged in, especially at the fuel pressure regulator?Fuel pressure measures within spec?
Everything but fuel pressure has been checked
Is it time to take it to someone?
Today i put in a new knock sensor. First unplugged it and just pinned it and it hit 6k once. Put in the new one and reset the computer and it only hits 5k. Timing does not jump around at all, no missing...nothing weird. TPS is in good working condition. Timing is dead on.
I doubt, infact, i HIGHLY doubt the fuel pressure is too low. Ill be very surprised if in both rigs the pumps werent pushing enough fuel.
Doesnt hit limiter driving it either.
Timing is dead on.
Do you hear any unusual noises from the engine? Sometimes mechanical noise can fool the knock sensor
Did you put in a brand new OEM Toyota knock sensor? Brand new aftermarket? Used? Correct for the application? Knock sensors are not universal, and aftermarket parts are not universally correct, nor of universally adequate quality. OEM vs. aftermarket is an entirely different argument, and I won't drag it out again here, but I do want to verify what you've done.
I was thinking more along the lines of excess fuel pressure due to a failed regulator.
I understand that the last truck that this combo was in also had a manual transmission, but is the ECU correct for a manual transmission vehicle? It will/should be marked either MTM or ATM on the sticker.
What happens to ignition timing as the engine approaches 4800 RPM?
Toyota's rev limiters are usually a fuel cut. They turn the injectors off outright until the RPM returns to an acceptable level. That's why you get the bip-bip-bip sound everyone else's rev limiter makes. What you are hearing is very different. I have a crisp $5 bill that says your timing is being heavily retarded because the computer's going into limp mode due to a failed knock sensor or a failure in the knock sensor circuit.
Used out of a 90 pickup knock sensor.
Connector looked good. I can get the original knock sensor off the 4runner that it is in.
No idea on the continuity between connector and ECU.
You really have to remember that it was in two different rigs and its hard to believe that the continuity on both could be messed up.
The last truck had a Manual computer. This one is using the auto computer.
When I did the swap the motor would not run or start at all using the manual engine harness with the manual computer. Its using the Auto Harness with the Auto Computer.
I did notice once that when I pinned it and it hit 5k, it went all the way back to before zero, and then it went back up to advanced like normal but it stayed at 5k.
You work at toyota, what are the years that are good that I could use one from?
So...that begs the question: does anyone have any empirical evidence that the automatic ECU does not have a 5000 RPM rev limit?
It did it in the other truck with a MANUAL computer, so no, its not the Auto computer doing it
OK, alright, chill out. I know you are tired of repeating yourself, but you have a metric shitton of different combinations discussed here and they are not all clearly identified or well organized. So it's worth asking the dumb questions to make damned good and sure we have the answers.I've given you all the advice I can. Whether you follow it or not is up to you. It was free, and a lot more than I owed you, so maybe you can find someone else to shout at. Cool?
just throwing this out there weak valve springs?? looks like you tried everything eles
Chris, what kind of exhaust manifold and exit tubing are you running??Is it the stock manifold that quickly (within 5 inches) goes from two tubes to one tube?? or does the twin tubes run down to just before the cat??
I make more money that you, my wife is hotter than yours, my thingy is bigger than yours
The new motor blew up today...
whats the plan now
Started by yotaismygame Toyota Pickup/4Runner Tech 1979-95
Started by 4Runninfun Toyota Pickup/4Runner Tech 1979-95
Started by remhex Toyota Pickup/4Runner Tech 1979-95
Started by peanutt Toyota Pickup/4Runner Tech 1979-95