My son and I are currently in the middle of reviving an '86 Firebird Trans Am that spent who knows how many years sitting idle. We've done a ton of work already and have it to where it went down the road for first time since we bought it in Dec. of last year. To date, the list of notable mechanical work completed includes:

• New fuel pump
• Quadrajet E4ME rebuilt by Ken at Everyday Performance
• New Edelbrock 3701 intake
• New Cloyes double roller timing set
• New harmonic damper
• New belts and hoses
• Restored factory wiring for the radiator fan. A previous owner had hacked it to pieces trying to install a manual switch. It works correctly now...sometimes. I'm pretty sure it needs a new temp switch.
• Mr. Gasket 180 degree thermostat
• Cooling system flush/fill
• Remanufactured water pump
• Remanufactured alternator
• New valve cover gaskets
• New front/rear brakes and brake lines
• Rear pinion seal and diff service
• New plugs/cap/rotor
• New vacuum lines. There was a lot that was missing/routed incorrectly. I put everything back per the VECI.

It starts easily, smokes a fair amount, idles around 900 when warm and has codes 13 and 21 (O2 and TPS voltage high).

We're at the point now where it's time to think about tuning it, so I'm hoping to get some advice on what order to move forward. I'm thinking it makes the most sense to go about it this way:

1. Address the TPS code. Warm the engine, check the voltage, adjust/replace TPS if necessary. Set to .48 volts at idle.
2. Address the O2 code. I'll most likely replace the sensor since the current one looks original. Check for alternating voltage as the car warms up. Ground A&B on the ALDL while running to check for open/closed loop to verify operation.
3. Adjust idle mixture screws.
4. Adjust idle air bleed.
5. Set idle speed idle. There's a process in my Haynes manual, but it talks about removing a vacuum line to the ILC...and mine is completely electronic. So I could definitely use some guidance here.
6. Reset timing. Base timing of 6 to 12 degrees seem to be common but VECI states 0 degrees at 500. I put it as close to 0 as I could after doing the timing set and before reinstalling the dizzy. Advanced it to 6 after we got it started because it idle like poo...but that was with no tuning and idle speed wasn't right.

I'm fully expecting to have to go back and recheck things as I move through the list.

I'm printing out the E4ME Service/Rebuild guide listed here and will be going through that with a fine tooth comb. Just wanted to try and get a head start on things first though.

Any help you all can provide would be greatly appreciated! Thanks!

 

Not to change the subject, but does your hood clear the air cleaner with the 3701 intake manifold?...

 

The boy put an Edelbrock air cleaner on there. It has two small marks where it appears to have lightly contacted the hood...or the insulation at some point. but the insulation was in bad shape so it's gone now. I'm pretty sure there were no clearance problems with the factory air cleaner though.

In fact, I'll probably put it back on when I do the tuning so I can double check for you.

 

1. Should be farther down on this list.
2. Duh.
3. They have no "authority". Do as near nothing as possible yet still occasionally a difference can be detected if you have REAL SHARP detection means and look close enough. Set em to about 6 turns out and forget em.
4. Should be #1 on this list. Set it to about 50% on a dwell meter attached to the bright green connector near the blower motor. That's 30° on the 6-cyl scale of the dwell meter. A little lower than that (indicates the carb is feeding slightly too much fuel - emphasis on slightly - rather than too high a number which means the ECM is trying to richen up whatever is going on naturally) is better.
5. No idea about vac line and ILC. Sounds like that's for some other kind of car. Maybe a 6-cyl or something, I haven't the vaguest dimmest foggiest remotest hint of a whiff of a glimpse of a clue about those, not sure I've ever even seen one. (I avert my eyes whenever that might accidentally happen to me) There's a screw on the side of the carb. That's all there is.
6. When will this s*** about "numbers" EVER stop? Trying to use "mark" and "tab" and "light" and "book" and "spec" is WORTHLESS. Set it to where it runs the best. There are ANY NUMBER of reasons for this; I'll start with the top 2. First is, you have NO WAY to know if the "mark" crap is ACCURATE. It ALMOST NEVER is even if all the parts are brand new. The "mark" on the crank damper isn't on the part affixed to the crank; it's on the outer inertia ring, which is only loosely associated with the crank by A BLOB OF SPOOOOOOGE, which tears, slips, and otherwise allows "mark" to wander about aimlessly. It's USELESS. Worse yet, if the timing cover has been changed, there's no telling whether its "tab" is in the right place. Second, "spec" in "book" was written for NEW cars in 1985 (86 cars hit stealerships in Sept 85) to match govt regulations in 1985 to meet customer expectations in 1985 with fuel available in 1985 with the car expected to drive anywhere from sea level (New Orleans let's say) to the Eisenhower Tunnel, temps anywhere from -40°F such as Fargo sometimes to +120°F such as Death Valley, with fuel you could buy in 1985 (watered down cat ****), with everybody imaginable driving it (grandma or your 14-yr-old nephew), and so on and so forth. It is NOT NOT NOT NOT NOT NOT NOT the setting at which the engine runs the best. Now, in 2024, almost half a century later, YOU get to decide what "the best" is. Set the timing there. It will be some combination of most power, crisp throttle response, low highway coolant temps, lowest fuel consumption, freedom from pinging, reliable starting, and ANYTHING ELSE that seems worthwhile TO YOU. YOU get to decide what "best" is. I cannot stress this strongly enough. People (well-meaning enough but misguided) will come on here and tell you all about "it should be xx° at idle and yy° at whatever", "my car runs best at zz°", and any number of other similarly USELESS blather and drivel. IGNORE all that. The fundamental problems are (a) you have NO IDEA whether any "numbers" you come up with are REAL, and (b) you have NO IDEA where to set it for "optimum" results, until you experiment (think of that as like a GPS receiver that tells you EXACTLY what coordinates you're located at which is what your "mark" crap would be IF it was reliable, but even if you had THAT, doesn't have a database that tells you where the place you need to go is, or what roads there might be that you can drive on to get there). Set YOUR "timing" to where YOUR car runs the best, the way YOU like it to run, the way YOU think is the best, the way YOU drive it, where YOU live and drive, on the fuel YOU can buy. Some "number" about "mark" and "light" and all that is WORTHLESS. I can assure you, NOBODY, not me, not you, not ANY OTHER yutz on the Internet, will know ANY BETTER than your engine does, what's best for it. Give it what it asks for. It will tell you how happy it is by how it runs. It DOES NOT whoop out "book" and look up "spec", then hook up "light" and examine "mark" and "tab", and on the basis of what it sees there, decide how it's going to run. "If it RUNS good, it IS good". Don't outsmart yourself.

#0 on your list should be, verify whatever idle speed you THINK your car runs at, with a genuine piece of test equipment. NOT the "sporty" wavy pointer trim package POS in your dash. In these cars, as well as any number of other models and years of cars that used the same circuit, it FAILS almost inevitably; and does so by reading higher than reality. to give you some idea, I had one in my collection of them that read 3 times the actual engine RPM, and out of the 5 or 6 I had, only 1 was within 10% of reality at idle. You're telling us your idle is 900 RPM; I'm telling you it's probably more like 600 or 650, because if it was REALLY ACTUALLY TRULY 900, your post would have included complaints of some variation of "it slams into D and R way too hard".

You will find that many adjustments interact. That is, you'll adjust one thing to get it as good as it can be, then some other thing will need to be changed, then some other, then you'll end up back at the first one. I would suggest, fuel level in the carb is the first adjustment; ignition timing is the next; idle air bleed next; that, and idle speed, will interact RUTHLESSLY, so be prepared to go back and re-do both of those acoupla times. Keep adjusting on it until EACH ONE results in the car running The Best It Can. By definition, this is "optimum" (Latin for "best"). Any adjustment other than this will not be as good, which you don't want. We call this process "tuning". "Tuning" does not consist of getting some "number" in your head and forcing it on your engine; it consists of making changes, seeing what changes make it better or worse, and keeping after it until every single thing you can possibly change is already the best it can be (any change from there makes it not as good).

#7 will be, set the TV cable properly.

 

Thanks sofakingdom!

Went through the Service/Rebuild guide today and that cleared up some of the questions I had...mainly my items 3 and 5. For 5, my carb has the idle speed solenoid (ISS) and not the ILC. ISS equipped cars get their idle speed set exactly as you mentioned.

I've seen you post about the timing numbers before and I completely understand your point. The car wasn't running when we got it, so I went with an initial setup that I was pretty sure would start w/out too much fuss...and it worked. We will definitely take your advice of "setting it to where it runs best" as we move forward. For now, I'm still working out the kinks. My experience level and the fact that the car isn't legal for road use yet limits me to what I can see/hear in my driveway. The "first drive" from this past weekend was just going the 1/8 of mile to the end of my street and back...

I'll see if I can get my hands on a scanner to verify RPM. Of the three times we put it in D, I did notice that it hit pretty hard at least one of those times. So while it might not be 900, I'm fairly certain it's too fast.

Thanks for the reminder on the TV cable. While that wasn't on my list above, I have a big piece of tape on the steering wheel with "TV cable" written on it...so we don't forget to set that also.

Thanks again!