I tried searching with no results. We have just completed a 3.4 swap from a 22re into a 1990. The vehicle is off road use only. It has a 95 3.4 with and 5spd manual mated to it.
The issue is that it idles fine and runs great at 1/4 throttle but any thing above that under load (while driving) it bogs and falls flat on its face. It does not die or sputter. There are no codes present and we have installed a new tps. The only thing not hooked up is the vss. The scan tool showed that the timing drops instead of increasing when under load.
Any help would be great as we are at a loss.

 

More info:
Auto ecu and wiring harness mated to manual trans.

 

Knock sensors? Maf? Vacuum leak? Fuel starve?

 

Ok, I am helping Brian with this problem and are just as baffled, here is what we did

Realized the timing of full throttle was retarding to negative, 0 or single digit positive timing advance (15-20 degrees at idle, 25-30 at light throttle), my dad suggested we unplug knock sensors thinking they were picking up something and retarding the timing, disconnected them, no difference, didn't even throw a code.

Checked the fuel trim at idle, it hung out somewhere between 5-12%, I never saw it while driving it but my dad did while also watching the timing and said it was fine and within spec but from what he told me, maybe on the high side of spec (20-25%)

Engine load with the code reader goes all the way up to 90-92% so the MAF sensor is fine, the Toyota manual says 90% is well within spec of an operational MAF sensor

The code reader says the transmission is in gear 1, I don't know if this means position 1 (park) or 1st gear which is usually referred to as L. I have jumped the two wires needed to tell the computer its in park/neutral to get it to crank, however, there are two other wires that need to be jumped to tell it what gear its in once running. I have tried every combination of wires on the plug to the shift indicator switch and the code reader never changes from reading "current gear - 1".

Personally, I think it is looking for a VSS sensor (which we don't have) since it might possibly think its in 1st gear and it wants an input from the computer or fuel pressure but the fuel pressure thing doesn't explain the retarding of the timing instead of the advancing of the timing.

In the Haynes manual, I don't remember exactly what it said but it was something along the lines of "the distributorless ignition system is controlled by various sensors that feed data into the ECM and then timing and spark adjustments are made, these sensors are the MAF sensor (which is OK), the TPS sensor (which is brand new), the ECT sensor (haven't check this but can't imagine coolent temp causing this) and the VSS.

To me after reading that it seems obvious that it is the VSS, are any of you guys that have done this swap with an auto harness and manual tranny seeing that the VSS needs to be present?

Thanks in advance, would really like to figure this out so we can go out to the desert and actually have fun with the truck

 

did you upgrade the fuel pump? you're goin from a 4 cyl.. to a 6 cyl... need the bigger pump. Is your crank pulley bolt nice and tight? they tend to back out. There is another member that I helped him with wiring. He put a 3.4 with an auto ecu into a manual 4runner but was a v6. He wheel it hard and all he did was jump it into nuetral.

 

What code reader are you using to get the current gear information?

I'd look at fuel too. What is your O2 sensor reading like? Has it skipped a tooth on the timing belt? If you have a cable driven speedometer, you can pick up no.1 vss from the gauge cluster.

 

We are using a Snap On scanner.

Here is a bit more info in this thread.

http://www.dezertrangers.com/vb/moto...ion/129737.htm

 

I know you said that the MAF looks good, but I had the same problem and it turned out my MAF was for a 97 and the harness I used was a 99. The wiring was off by 2 wires. Adjusting this allowed the motor to work flawlessly. just my 2 cents...

 

From your other thread...

One time I had a bad solder joint to a power wire for the ecu. It would start and run but the cel would not light when there were sensors disconnected. Took me a while to find that one.

 

did this ever get resolved? I am pretty much in the exact same situation, except that I have a manual ECU. I do have an inline Wahl pump helping out the 4cyl to feed the motor.

When it hits 3500 RPM? (no tach yet) it bogs down just as if the timing is being retarded instead of advancing.

As for the VSS.... I sent that signal to the ECU via the dash as that's how my 89 4Runner was originally setup. Is that what you did? Could it really be the VSS?

 

Sorry it took so long but it ended up being the ecu. We put a new one in and problems gone. Runs great now.

 

So im a little confused. I have a gold pin on my MAF and a gold pin on my sensor plug. I tried to rearrange the pins but it doesnt start up at this point. I had the MAF code that the thread starter has as well. But i just cant seem to find the correct pinout setup to get the rig to run. I feel like that gold pin is a factor