anyone running a Caddy 4.9 with a CARB ? was wondering since the caddy bolts to the 125 (it does, doesn't it ?), if someone didn't want to run all new computer & wires.... anyone running a non computer 4.9 ? any BAD (weak links) to this engine ?) Thanks

after searching , seems I'm going to be having to use a computer, no matter if carbed or not. So, are there any weak links to the 4.9 for an everyday car ? can someone Post a Link with a step by step for this conversion ? thanks

4.9 Swap
http://www.fieroaddiction.com/caddy49b.html

4.9 ECM reprogram
https://www.fiero.nl/forum/Forum2/HTML/115182.html

4.9 Oil Filter /Cooler
http://www.westcoastfiero.c...l_filter_bypass.html

4.9 Swap Harness (Shameless self plug)
http://www.reddevilriver.com/Products.html

yes it will mount to the 125 tranny and no you shouldnt mount it to the 125 tranny not only will your destroy the trans you will get crap everything from the motor untill it goes boom. the 125 trannies are ot good for.....anything really :-/

Use the 4T60E from the donor car - if you can get one from a Seville or Eldorado it will have the 35/35 sprockets and 3.33 diff.

Makes a HUGE difference compared to the Deville tranny and is a great DD.

I am curious why the need to use a computer if going to a carb. Is this in relation to the distributor or something else. Would like to know for my own morbid curiosity.

i dont believe you need the computer fr engine management if going carb but the 4t60e is shifted using the computer. if you cant find a 4t60 then its mechnilly shifted and you wont need the computer

As mentioned, you are far better off using the 4T60 if going carb - you will also have to modify a distributor to work with the 4.9 as well. I do believe there are threads on here that go about the process of doing the distributor mod. I do not recall of hand of anyone that has a 4.9 with a carb setup running.

Don't see a real reason you would want to anyways, see here for all the info you need: https://www.fiero.nl/forum/Forum2/HTML/098096.html

Just wondering how the price of the carb, pass through fuel pressure regulator, intake (if needed), adapters, the distributor mod so it runs a vacuum advance, and transmission compares to the price of a harness and an ECM tune.

I would think they would be at worst comparable.

Clearly the injection set up would work better and deliver better mileage. I would also think it would be easier to do the injection set up rather than deal with the carburetor.

* disclaimer needed since I sell conversion harnesses and thus might have a slanted opinion.

id have to agree with phonedawgs. while you could do a carb setup theres no real reason for it as its going to be more expensive and deliver less on fuel econ. my 4.9 was the first swap i ever did, i built the harness myself with the help of mickey's totally awesome well written guide and tons of questions in the tech section. seeing as i was an amature it took me a little over a month to d theharness working on it a few hours a week (prolly 20 hours total of disassembly labeling and reassembly) and it looks somewhat like a rats nest. if your ot savy in wiresi reccomend having someone build the harness for you as it can get complicated. thats what i plan todo with my 3800 swap.

If wiring is a problem, how about using a 16149396 PCM. Granted you loose the sequential injection, but you still have the ability to control the 4T60E. With that, the ecu can mount in the engine compartment without having to worry about all the wires going through the firewall. Less wiring to deal with and less wire to string out, and not having to teach it how to idle.

I have used this ecu on a couple of other projects, and it works great with the right code. The nice thing is that it will also run the code made for the 7730/7727 ecu. I used one on a 79 Dodge Omni with a 90 VW Golf GTI engine and trans swapped in with the 8D code running it all. Tuning will be the biggest hill to climb on this one.

Worth thinking about for those interested.

quote Originally posted by chetw77cruiser: If wiring is a problem, how about using a 16149396 PCM. Granted you loose the sequential injection, but you still have the ability to control the 4T60E. With that, the ecu can mount in the engine compartment without having to worry about all the wires going through the firewall. Less wiring to deal with and less wire to string out, and not having to teach it how to idle. I have used this ecu on a couple of other projects, and it works great with the right code. The nice thing is that it will also run the code made for the 7730/7727 ecu. I used one on a 79 Dodge Omni with a 90 VW Golf GTI engine and trans swapped in with the 8D code running it all. Tuning will be the biggest hill to climb on this one. Worth thinking about for those interested.

IMHO - same amount of work when it comes to splicing in the wiring to merge the engine to the Fiero. There is nothing wrong with using the 4.9 ECM and it fits nicely in the stock location and with a little bit of effort the wiring can be made to look stock. Tuning is not an issue if you are keeping the stock configuration - Stickpony already does a fairly good job at reprogramming the ECM.

Wiring is not that hard when you take the time to do it 1 wire at a time - I have found that people just get in a rush and hurry through the wiring and then wonder why there is a problem. Or the other side of the coin is they panic when they see all the wires unwrapped and run away. The other problem is people NOT labelling the wiring when they take it off - when you remove the C500 harness from the original motor, it is so much easier if you label each wire where it went to - chances are pretty high that that same wire goes to the same spot on the new engine (same with the C203 plug) - the engine to ECM wiring remains unchanged with the ONLY exception of having to shorten (or lengthen) the wire for the new ECM location.

There is still exaclty the same amount of wires to merge from the engine to the Fiero with a carb setup (unless you eliminate all your power feeds and instrumentation - that is all the C500 and C203 are responsible for). But now you have to make and install a different distributor, add a carb (and make an adaptor plate) - keeping the injection system is well documented, switching over to a carb not so much so and you will be mostly on your own (I think the people that attempted this are long gone from the forum).

To continue what Mickey Moose is saying...........

The 4.9 will make more power with the Port Fuel Injection than it will with a carburator. It will also get significantly better gas mileage.

The 4T60E that GM mated to 4.9 to makes for a great comination in the Fiero, gobs of torque and no hassles driving. When properly installed, the drivetrain performs as though it came from Plant #17.

quote Originally posted by Mickey_Moose: IMHO - same amount of work when it comes to splicing in the wiring to merge the engine to the Fiero. There is nothing wrong with using the 4.9 ECM and it fits nicely in the stock location and with a little bit of effort the wiring can be made to look stock. Tuning is not an issue if you are keeping the stock configuration - Stickpony already does a fairly good job at reprogramming the ECM.

I put that out there as an alternative to the stock 4.9 stuff. There are fewer wires to deal with but then there is the throttle body. The 396 pcm cannot run the stock ICM on the 4.9, one would need a throttle body with the IAC motor. Just an idea. I on the other hand am going with something that is far from stock, could be scary. Wait and see.

Better yet find a 4t60e from a lumina 3.4 dohc car, 3.42 final drive this trans will not shift like a caddy either. I did have mine built with better internals and the shifts are awesome!

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2008 ZX-10R
1994 ZX-7-9R
1986 GT 4.9 4Auto