As the topic says... I recently purchased an 88 GT with a Quad 4 Getrag. Bellhousing swapped to V6 style. (I knew this, going in.) I keep getting a Code 24 after driving for a while. Speedo works perfectly. I'm wondering if the Code 24 is caused by the speed vs RPM error introduced by the difference between the FDR in the stock and replacement trannies. Kind of a longshot, I suppose, but it is programmable in the ECM. It's also interesting that it doesn't set the code right away. Am I over-thinking this?
I've read all the threads here that contain "Code 24", but have not started troubleshooting yet, other than having unplugged and reconnected my speedo connector.
Anyone else running a Quad 4 Getrag or, I suppose, an F23?
I know that some Quad 4 Getrags (maybe all) use a different style VSS than the Fiero Getrags. I know that when I did my Quad 4 swap, I split the case and installed the plastic gear so that I could use the Fiero VSS. I think that the Quad 4 VSS outputs pulses instead of a sine wave. I'm not sure what kind of engine/transmission your car has but perhaps the code 24 is being set because the ECU is expecting a sine wave and it is seeing a pulse.
Also most of the Quad 4 Getrags have the same FDR as the Fiero. Only the W41 Quad 4 Getrags got the 3.94 FDR so they are rare.
Hmmm... Interesting. Conflicting stories, over the years. I'll have to measure speed vs RPM, and see. (It has a lot more "giddy up" than I remember out of a 2.8.)
The VSS looks, outwardly, like the Fiero VSS, but I haven't pulled it out. (The speedo and odo both work perfectly.) I've got another Quad 4 Getrag that very obviously is the magnetic VSS, but the VSS looks completely different, even on the outside.
Even with the 3.61 FDR a Quad 4 HO is much more capable and fun than a 2.8.
I have a W41 that will be going into my 84 Quad 4 in the next few months. I also have three other Quad 4 HOs in the garage. I have been contemplating stroking a 2.3L Quad 4 to 2.6L with the 2.4L Twin Cam Crank. The block will be bored to either 93 or 94 mm from 92 mm. With additional compression ratio (11.5:1) I think it could produce 230 HP.
Even with the 3.61 FDR a Quad 4 HO is much more capable and fun than a 2.8.
No doubt! It's better suited to the flavor of the car. Like an LQ1. (I have heard that the LQ1 was part of the inspiration for the Quad 4, but who knows...)
I did some experimenting yesterday. The scan tool is seeing MPH displayed, along with the speedo (which has always worked properly). So if there's a failure, it's intermittent, and between the speedo and the ECM. The light was NOT on.
I know there have been a few turbo Quad 4 done. The 2.6L stroker is fairly straight forward. I just don't know if I want to spend the time on a turbo project.
