Vacuum leak detection.

In this article I’ll cover the general things that apply to all Fiero versions, then later I’ll break out the version specific and detail items. Contrary to popular belief, vacuum plumbing problems are a major issue. Even small vacuum leaks can cause major headaches.

A major problem? Why?

The ECM will try to compensate . . . → Read More: Vacuum leak detection.


The Assembly Line Diagnostic Link

Warning! Don’t force anything into the ALDL connector! If you damage the connector then you can have problems when using ECM scanners and other tools that have the proper size terminals.

Note! It is possible that the ALDL may be installed with the Key up or down. The above picture is Key . . . → Read More: The Assembly Line Diagnostic Link


Making Sense

The table below list the sensors by name, the engine types it is found on, the class of sensor it is, mounting characteristics, and very briefly what it does. It is intended as a quick reference only. For more detailed information read the related article(s). WARNING! Over torque of NPT threaded sensors can cause . . . → Read More: Making Sense


Knock knock….

Who’s There?

Ping. Ping Who? Ping I just knocked a hole in your piston….

Engine Knock, Fuel Octane and other myths

Thing One: Never use higher Octane fuel than the engine needs to prevent knock.

I’m going to try to greatly simplify a very complex topic here. They write encyclopedias about this stuff. I’m . . . → Read More: Knock knock….


Iron Duke Performance FAQ:

Here are some interesting incites into the Iron Duke’s performance potential.

by: Gary Ohst

>> I was hoping anyone could tell me what the difference is between the SD valve cover and the stock 2.5. Specifically is the bolt pattern the same and is there room for needle bearing rockers?<<

The bolt . . . → Read More: Iron Duke Performance FAQ:


Fiero Emission Control

Notice! It is a violation of U.S. Federal law to remove, modify or disable emission control devices. Some states, like California, have laws above and beyond Federal regulations. Fiero has very little in the way of emission control hardware. There is only the catalytic converter, EGR valve and a fuel vapor recovery canister. None . . . → Read More: Fiero Emission Control


Engine & Tranny Mounts

4 cylinder motor mount

There are 2 kinds of motor mount available for Fiero 4 cylinder. (I think this applies to all of them…) You can get them solid or liquid filled. The solid is a little less expensive but the liquid filled is better at isolating vibration. Of the two, I prefer the . . . → Read More: Engine & Tranny Mounts


87-88 4 Cylinder with Serpent Belt

While this article was originally written for Fiero 1987-88 L4, it applies to all vehicles with self tensioning serpent belt systems. WARNING: Do not assume that the belt listed in the catalog fits your engine! If the belt forces the tension assembly out of range you can and likely will break things. WARNING: NEVER . . . → Read More: 87-88 4 Cylinder with Serpent Belt


700 Series TBI

The TBI used for 87-88 Fiero 4 cylinder motors is the 700 series unit presently manufactured by Delphi Automotive for GM. You can find Delphi’s public relations info for the 700 TBI here. The information includes images and general specification data. The articles that we’re interested in at the moment are “Throttle Bodies – . . . → Read More: 700 Series TBI


4 Cylinder Timing Gears

4 Cylinder Timing Gears

NOTICE! This is an unfinished document. It is a collection of all the stuff I’ve come up with tested or not… USE IT AT YOUR OWN RISK!


Cam jobs suck under the best of conditions. The majority of FWD and Fiero cams are never fun to work on. Here’s . . . → Read More: 4 Cylinder Timing Gears

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