Hesitation (??) on 2.7l hilux engine

[3rz_runner]

Hey,

I've had a 3rz conversion (2.7ltr hilux petrol engine) in my 4runner for nearly a year now, and have had an issue with what I would call a "hesitation". Basically it feels like the engine surges a little between 2000-2500rpm, and only at say between 1/4 and 3/4 throttle. Some days it feels worse that others, but it does it none the less. The engine is dual fuel, and it does it on both fuels, so probably rules out fueling probs. Also I've replaced all plugs and leads with decent items and no difference. Its recently had a gas research carby fitted, still running both petrol and gas, and fitted a haltech interceptor ecu at the same time and had it dyno tuned, but still has the hesitation.

Anyone have any idea what it could be? Its hard to explain, but hopefully you get what I mean :confused: The only other "basic" thing I could think it may be is coil packs... Any idea how to test these?

Thanks
Simon

[Pog]

I had exactly the same problem with mine. Disconnect your battery, take your AFM out of the intake pipe (unplug it first) and give it a good spray out with CRC Contact Cleaner. There are 3 hotwires in total that will need to be cleaned if you have a look at it from all angles. Leave it to sit for a few minutes for any excess to evaporate off, put it back in and reconnect the battery and take it for a test run.

I am 99% confident this is your problem! :)

[3rz_runner]

Bugger, coz I did that only 2 weeks ago, and have done it quite a few times since having the engine in and it didn't make a difference. I was using an electronic component cleaner, might try a contact cleaner and see if it makes a difference...

Thanks mate.

[Pog]

Your AFM might be stuffed. Got a mate with a 3RZ? Beg, borrow or steal another AFM to try out if you can.

Make sure you give it a good drenching too. You should be able to see with the naked eye whether the wires are clean or not.

[3rz_runner]

Cleaned it up yesterday, but haven't had a chance to test it yet... The wires are spotless, so there shouldn't be a prob, unless as you said the afm itself is buggered. Will look into getting another for testing purposes.

Cheers mate

[DAB]

Check the Throttle Position Sensor. Basically a variable resistor.

[Pog]

Check the Throttle Position Sensor. Basically a variable resistor.
Where abouts is the TPS on the 3RZ DAB? I havent become too familiar with those aspects of mine just yet, but always good to know where to look!

[3rz_runner]

Its located on the side of the throttle body, its on the side closest to the firewall.

DAB, how to you suggest to check it? I don't think their adjustable unless you oval-ate the mounting holes yourself...