4.9 Allante fuel rail inlet...? (Page 2/2)
lou_dias APR 21, 03:57 PM
When I did my Allante swap, I had purchased a custom fuel rail for it from someone. Of course I forget who. It was 10+ years ago...
Raydar APR 22, 03:22 PM

quote
Originally posted by Will:
It would not be hard to take some stainless round bar and turn a replacement on a lathe. The replacement would just have 1/4" or 3/8" NPT (pipe) thead instead of GM's right angle connection. If you want to mail me the fitting, I can model it and make the drawings.



Thanks Will.
My fitting is fine. I was inquiring for someone else, who is doing an Allante intake setup.
I think he still has his inlet fitting, but he might be interested in having/making more. I'll forward him this thread.

V8 Formula APR 23, 02:35 PM
I don't mean to hi-jack this thread, but since all the Caddy guys are here I have a somewhat related question. I just bought an Allante 4.5 engine (that came with the fuel fitting thank goodness) but it has no wiring harness. I've built wiring harnesses a couple times on different swaps in the past so I'm good with wiring, but can I just go to my local salvage yard and get a 4.9 wiring harness and use that for the fuel injectors, distributor, alternator, sensors, computer, etc? I'm wondering if the connectors are mostly the same for similar years. Thanks.

Rick Stewart
Raydar APR 23, 09:39 PM
My 4.9 was installed by the Fiero Factory, using a harness that they sourced. (Injection Technologies?)
When I installed my Allante intake, I had to extend the wires for the IAT sensor, and (I believe) the ISC motor. The pinout was "one for one". Nothing was crossed up. The wires were just too short. The Allante also does not use EGR, so all of that was just unplugged. You will also find another small connector that is unused - both on the 4.9 and the Allante, as installed in the Fiero. (I believe it is red in color. Possibly a power steering pressure switch. I believe those pins should be jumpered on the ECM, but don't hold me to it.)

The only "gotcha" I ran into was the TPS. IIRC, the 4.9 TB places the wiper on the center pin. The Allante TPS uses a different connector, similar to the stock Fiero V6, which must be spliced in. The wiper ended up being on one of the end pins. Not too difficult to figure out, once you realize what's going on. (The main symptom? My auto trans shifted at some of the strangest times.)

Obviously, this is not a direct answer to your question, but it's the best I've got. Long story short, the wiring is quite similar. (Sensors, injectors, etc.)

Keep in mind that if you are using the Allante automatic trans, it is a much different beast from the 4T60E. It's called an F7. It's kind of a half-step between the 4T60 and 4T60E.
Of course, if you are doing a manual, it will simplify your life greatly, in this regard. Just jumper (ground?) the appropriate pins, so that the PCM thinks it's in "drive".

[This message has been edited by Raydar (edited 04-23-2020).]

V8 Formula APR 24, 04:20 PM
Thanks, that helps a lot.

Mine's a Getrag so no worries about the transmission.

Thanks again, +1 for you.