jeremy9allen

Hey!

I just replaced a motor in an 02 corolla (1zz-fe) A japanese take out motor was installed in place of the stock one.

The car intermittantly bogs from a standing start. You will roll slowly from a stop no matter what throttle position you have- then all the sudden the motor comes to life and you take off like a bat outta hell. (1 out of 10 times)

All sensors seem to read good. I replaced the TPS and cleaned the MAF and throttle body just for the hell of it. IAT and ECT read good too.

It acts like a bad MAF, but it reads out good on the scanner, and I don't have one to try in its place. But the car ran fine and never did this before.

Anyone know if the VVT solenoid would give symptoms like this? Or any other ideas? Any forums I can be directed to if this isn't the proper place to ask?


Thanks

scuba

Dude I know there's Rolla Forums all over the net..

DeathCougar

iTrader: (23)

There is no such thing as a "VVT" solenoid. VVT-I stands for Variable valve timing with intelligence. The VVT is a coupling on the end of a cam shaft (intake IIRC) and would not likely change anything.

Since you bought one of those Japanese crate engines ( people never learn) I would make sure you got everything swapped over that wasn't the actual engine. Did your old engine have EGR, and the new engine doesn't? Thats a very common problem I run in to working at a wrecking yard. Was the new engine a 1ZZFE w/VVT? 1.8L? Or 1.7? I have seen many times when crate engines are NOT the same engine, despite what they tell you at the crate engine shop.

jeremy9allen

now you got me worried. I left most of the sensors on the "new" motor. I am refering to the solenoid on the front of the motor that sits horizontal facing the front of the car as the vvt solenoid. I am sure there is a proper name.

DeathCougar

iTrader: (23)

If you are talking a round looking sensor, that would either be your cam angle sensor, or the VVT sensor, depending on where you are talking.

Do you still have the old engine? Can you compare the two to make sure everything is exactly the same?

86Toyrunna

X2 on what DC is saying... iv fought a jdm engine swap a time or two with friends or familys cars. Remember they spec things differntly over there and some sensors may look the same but could opperate at a differnt resistance.. by chance if you didnt swap things from the old to the new did you install the ECU that was originaly with the jap engine? if not your current ECU may be hunting for info or signals that are not there or are not correct. I work on heavy equipment for a living and i know that when ever i replace a engine (mainly IZUZU diesel tier II and tier III spec'ed) you HAVE to instal the new ECU that the engine was spec'ed with. other wise bad things will happen and it will piss your face off big time lol... that is just what first came to mind, like i mentioned that is baised off of what i know will happen with izuzu's. good luck man

jeremy9allen

I do still have the other motor. I re-used the vehicles original wiring harness and ecu. I'll have to get a good look at it on monday.

I guess I will start out by reinstalling the original sensors. There is not much to the motor, and no EGR by the way, DC

I am going to say it is the correct displacement. The long term fuel trim was at 0 after driving for 30 min or so.


One thing I thought I would mention- The car had a bad o2 sensor and would not go into closed loop (it set a code for this).
It was only after replacing the o2 and the car going in closed loop that this problem showed up. I did make sure to clear the adaptives,

So I would have to think it would be an input sensor causing this since it never acted up in open loop running under predetermined values.



But damn, this customer has had a bad o2 for the last 50k. They may have had this issue before if they would have gotten the o2 replaced before the motor swap.


Wish me even more luck

jeremy9allen

even thought the grams read out ok, it ended up being the MAF sensor.

DeathCougar

iTrader: (23)

weird that replacing an engine causes the MAF to go bad?

jeremy9allen

It probably was bad. But like I was saying, the customer had a bad upstream o2 for a long period or time. At least the last 50k miles or so that I am aware of. The car was never going into closed loop and it was running in a failsafe mode.


So if the o2 sensor would have been replaced before he was in need of a motor, the problem would have showed up with the old one anyways. It sucks when a pre-exhisting problem is made to look like the result of something you just did.

The car has about 230,000 miles on it. Now maybe it can get another 200k.

tommytuttle

I have an 00 corrolla, it bogs as well.. feels like MAF but no codes.

must not be as dramatic as you have.. I just live with it.