Wheelbarrow

Hi guys

I am new to the forum. I have a 84 3.2 carrera. When driving with gentle throttle delivery between 2000 and 3000 rpm it has a juddering affect.
Any ideas on why? And how to fix it?

Any help is much appreciated

Amber Gramps

Not sure how we missed this post. Welcome. My first question is what gear are you in? These things like to be revved, not lugged......

JCP911S

My 84 has a rough transition from the idle circuit to main DME. I think this is typical of the system, is a bit annoying, but can be adjusted. My guy set it at about 950 RPM, and I just drive around it.

But in my experience at 2000-3000 power from the 3.2 is V8 smooth, even with light throttle in any gear. These engines are very torquey.

Certainly, abrupt lifts off throttle can unsettle these cars, but sounds to me like the injection needs adjustment. That is not normal.

Hunt3R

Could be a few different things causing it from the AFM malfunctioning to simply the CHT sensor failing. Testing the resistance on the cylinder head temp sensor is probably the easiest first step.

Amber Gramps

I think the best money I ever spent on my engine was the $80 to clean the fuel injectors. Ya, sensors and switches all helped with peace of mind, but man, clean injectors rock.

If you don't have someone local http://www.witchhunter.com/ is the place to go.

My guy is Gonzo and his number is 909 915 5159 out in San Bernardino, Ca. He's half the price of everyone else. He's still not got a website, but here is one of his current craigslist ads: http://inlandempire.craigslist.org/ptd/4463164322.html

oldskewel

My guess is the AFM. You can check the resistance as you move the door from closed to open. Proper specs are in the manual and will indicate if there is a problem. The failure mode is that the potentiometer that the wipers wipe on fails and the resistance is not what it should be.

Tacet-Conundrum

No relation to Aforementioned!

awhenry

fuel filter is my guess. Change it out and then fill the tank with "good" fuel. Maybe add some Redline fuel injector cleaner and take it for a long drive.

Tacet-Conundrum

How easy is it to check the Throttle Body and MAF on these cars?

User 4221

The MAF is actually an AFM (air flow meter). They are also known as the "barn door" since the guts look like a big door that is moved by air flow. The barn door runs an arm that tracks a variable resistor that provides feedback to the DME to make decisions on air/fuel mixtures.

They are very easy to check with an ohmmeter and are are very well documented.

The key is to have a smooth reading throughout the travel on the internal arm.

This is a good start to understanding them: http://www.the944.com/afm.htm


Now, waiting for Loren in 3..... 2...... 1......

Amber Gramps

I'm a happy customer....that's it. No different than telling my friends that I'm happy with my new Toyota. If rennlist has a site sponsor that makes a living cleaning fuel injectors then please, go with it.

Just noticed your avatar. LOL