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 |   |   |  4G63 Issues, Mazda2 Parts, Suspension, and More! - Question IT
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4G63 Issues, Mazda2 Parts, Suspension, and More! - Question IT

Fixing what you broke

Eric Hsu
Jun 1, 2013

Got a burning question or simply need some advice with problems you've encountered while wrenching on your current/future projects? Ask our automotive guru Eric Hsu anything-literally, he's going to answer every single question, as long as it's automotive related.

Got a tech question? Send it to

Mitsubishi 4G63 Issues

I own a '98 Eclipse GS-T Spyder with idling problems. First it was idling high when I got the car running decent. I would play with the A'pexi Super AFC Neo and get it to idle at 1,200 to 1,500 rpm, just good enough to drive. The engine was outfitted with a set of Crower 272 camshafts so I didn't want it idling really low but I still couldn't get it to idle right. Many test runs with the AFC yielded not much better results. But I am getting this tuning stuff down, which is a definite money saver! One night the car suddenly died out on me and didn't want to start so I had to tow it home. The next day, I looked over everything, and it started up but idled around 500-600 rpm. I also heard a weird misfire, but once going down the road there isn't a power loss. The firing sounds are coming from under the valve cover every once in a while. I double-checked to confirm that the ignition firing sequence is correct while also installing a new set of Iridium spark plugs and Taylor 8mm plug wires. The car has a GM blow-through MAF translator that seems to be working. The PowerDex is telling me 16.00 after the misfire and then the car will stall and not pull itself out of a hole when it does. Initially, the engine was experiencing cooling problems, but I fixed it and put in a new temperature sensor that seemed to help the fuel trim some. My brother said he had some loose solderings in his '95 E-prom ECU. Will the '95 E-prom work with the '96-99 cam knock crank ECT sensors just fine? If all else fails I would want to swap to a boost-friendly E-prom. Thanks.

4G63 issues mazda2 parts suspension more apexi super AFC neo Photo 2/4   |   Question It

-Tyle Westmoreland, via

Diagnosing a car online is never easy. Try calling a doctor and telling him that sometimes you have coughing fits. He won't be able to tell you what's wrong over the phone or by email either.

If you did not make any mechanical changes between the times of high and low idle, then I suspect you may have a mechanical issue. An engine will usually idle high with a vacuum leak. Another cause could be a bad idle speed motor, air bypass screw too far out, bad throttle position sensor, or the throttle stop screw on the throttle body adjusted incorrectly. Any of these issues can also cause the ECU to freak out and go into a limp home mode that can cause the engine to not start.

I'm assuming you have a check-engine light so you can also plug in an OBD2 scanner to see what codes it reads. If you haven't thought of that, I'm not so sure you should be trying to diagnose this problem yourself. Saving money is one thing, but trying to diagnose the issue without knowing how things work isn't doing you much good either. At the very least, get yourself a factory service manual and follow it step by step.

It sounds like you have several items that were also wired in to the engine harness such as the MAF translator and AFC. You should also check the wiring on these items. Your setup sounds like its '98. Technology has allowed the consumer to step up to stand-alone ECUs that can entirely control an engine within a single control unit affordably. You should probably suck it up and get yourself an affordable stand-alone ECU such as a Haltech or AEM. Using signal translators and cheaters is a thing of the past. You wouldn't want to go back to a 28.8K modem and dial-up Internet access, would you?

Where to Start?

I own a '12 Mazda2, and have been looking to upgrade it with aftermarket parts to make the car more fun to drive. I went to a few automotive stores here in Oahu to attempt to see what they suggested but the advice I was given was: "There are no parts like that for your car, either it hasn't been developed or it's too new." Or I get: "Why would you want to mod that car." In my defense, the car is lightweight, and I want to be one of the first to do so. Do you have any tips on a good starting point to look for parts or advice on where to begin?

-Kris Wood, Oahu, HI

Have you heard of a website called Google? In about 20 seconds, I found headers, intakes, exhausts, and suspension upgrades. No kidding. It took me 20 seconds. Racing Beat appears to have a small product line for the Mazda2. I recommend you look them up. RB has been around forever and they have always made quality parts. In case you don't know how to use Google, here's RB's web address: You're welcome.

Suspension Overkill?

I own a '88 CRX that I am modifying to become my street/track monster but cannot accomplish this without the proper suspension setup. Although my question may vary from FF to FR setups and many other combos, I would like to find out if there is such a thing as too stiff of a suspension. I am contemplating purchasing a set of Skunk2 Pro S coilovers for a nice, firm feel with 18kg front, but I am questioning the rear spring rate. I was thinking of 12kg rears. I am an amateur in the suspension world, but always had a knack for wanting to learn about different setups. Forums are often no help so I am resorting to asking you guys.

4G63 issues mazda2 parts suspension more skuk2 pro s coilover Photo 3/4   |   Question It

-Jose, Chicago, IL

Yes, there is such a thing as too stiff. A suspension that is too stiff will cause the tires to lose contact with the road surface or greatly reduce necessary forces on the tires required for traction. Naturally this will result in a loss of grip and limit the car's road-holding ability.

Springs cannot just be randomly combined with any damper. The damper's valving and/or damping adjustment needs to be able to keep up with the spring's rate or the damper will quickly be destroyed. I'd recommend you ask Skunk2 about installing springs that are nearly double the original rates of the included springs.

Skunk2 has developed and tested their suspension kit so I would probably try the coilovers as designed first as long as you're using the suspension for its intended purpose. Building a street/track monster doesn't happen overnight either. Installing random coilovers with 18 and 12kg springs isn't going to turn you into Michael Schumacher overnight either. Starting off with a proven coilover kit will make it easier to learn how to drive the car too. Just like Tiger Woods would kick my ass at golf with a set of $69 Kmart clubs, Schumacher will kick your ass in a bone-stock Civic at any track. It's not always 100 percent about the parts so remember to concentrate on improving your driving skills too.

Old School

I purchased a '73 Datsun 610 sedan with 65K miles from my great uncle and was curious if an SR swap would be any different on the 610 than the more popular 510. I can find plenty of info on 510 swaps but not 610s. If it's too tough I'll just enjoy it in stock form. It's a fun little car. Here's a pic! Thanks.

4G63 issues mazda2 parts suspension more datsun 610 Photo 4/4   |   Question It

-Austin Pahl, Creighton, NE

The U.S. 610 models shared the same L16 inline-four as the Datsun 510 used. With that being said, I don't see why an SR couldn't fit with a little ingenuity. In Japan, the Bluebird (as it was called there), had an optional 2.0L inline-six. The bore spacing on the old Nissan straight-six was pretty tight compared to today's inline-six engines, but maybe you might even be able to squeeze in an RB25/26! An SR swap is fairly boring these days, isn't it?

Car Nut

Hello, just a quick question. I'm looking into starting a career in the mechanic world but I was also thinking that working dynos would be a really good job to have. What would I have to do as far as school or to get started on this path? By the way I've been reading the magazine since I was about 11 (25 now) and you guys have turned me into the car nut I am today.

-Owen, Gouverneur, NY

There aren't really any schools that teach you how to use a dyno exactly, but keep in mind that a chassis dynamometer is really just a large tool or measurement instrument. Think of it as a dial caliper for the car's power output. With that being said, you'll want to have a solid understanding of all automotive things mechanical. The more you understand about cars, engines, engine controls, and drivetrain, the better you'll be able to utilize a dyno.

If your local city college auto mechanic trade programs aren't for you, then there are several mechanical trade schools that come to mind such as UTI and Wyotech. Many of the city college programs (in Los Angeles at least) are specific to certain brands and after completion of their programs; there is help with job placement at car dealerships also. A dealership mechanic's job is all about getting the car in and out as fast as humanly possible and that may not be what you are necessarily looking for. More specialized programs are available at trade schools like UTI and Wyotech. The emphasis on automotive diagnostics also goes a long way to teach an aspiring mechanic how today's complicated cars work at an in depth level as well. This learned knowledge goes hand in hand with a diagnostic or tuning tool like a chassis dyno.

Engine upgrade

I own a '96 Mitsubishi Eclipse RS with the 2.0L non-turbo. I love the car and I am getting ready to do my winter maintenance. The head gasket is also going to be replaced. Since this is going to be done, I thought why not upgrade the valvetrain with new parts? My goal is to build a daily driver that will see some track time, but mostly autocross events. Unfortunately, I always hear this motor isn't worth upgrading unless you bolt in a turbo. My horsepower goal is 235 hp, and I wanted to start with massaging to the cylinder head. What are your suggestions for a reliable build?

-Matthew Williams, via

Your 2.0L Chrysler 420A engine came stock with 140 bhp. To gain an additional 95 hp without the addition of a turbocharger is not impossible, but will be very expensive. The modifications would make the engine difficult to drive on the street with its short life span, loud exhaust, and poor idle quality. The headwork, valvetrain, bottom end components, ECU, and labor required to attain your goals would also be very expensive. Trying to make over 100 hp per liter is generally reserved for the larger budgets of touring car race teams. If your goal is truly 235 hp, then have a serious look at Hahn Racecraft's Stage 2 turbo kit for the Eclipse RS. At under $3,000, it's going to be the absolute best bang for the buck. HR has been making these turbo kits for a very long time too so I'm sure it has been very refined over the years. They are located in Morriston, FL, and you can email them at

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