79 Jeep Cherokee, AMC 401, T-18 manual trans, hydroboost, 16197427 MPFI system---the toy
93 Jeep YJ Wrangler, 4.0L, 5 speed, 8.8 rear, homebrew hub conversion and big brakes, hydroboost, 2.5in OME lift, 31x10.50's---the daily driver
99 Jeep WJ Grand Cherokee limited, 4.0L, auto, 2wd, leather and power everything, 99% stock---the long distance highway ride.
now the vats deal would be cool. since i have it in a 92 camaro it would be cool to have it wired up as well.
We should update the GIF on the front page to t he revised version found here: http://www.thirdgen.org/techboard/po...82-post40.html
Notably, the P/N switch is updated. I've been beating my head against a wall because my IAC isn't working right. Because I don't have the wire hooked up, because it was not on the sheet. It was not grounded so it thought it was in drive and would not do the pintle thing.
Thank you and done!
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
-= =-
I have checked the pinout on the first page and cross checked factory pinouts from C/K and S/T vehicles using the same PCM family with manual transmissions. I see no park/neutral switch input or grounded signal wire listed in the OEM diagrams. Also, the two factory diagrams I have show both VSS and trans speed signals connected to the pcm in manual trans applications.
Does anyone have confirmation of P/N input on E5, or of the results of not including the VSS / trans speed signal on F13?
Thanks
Last edited by 1project2many; 08-13-2012 at 07:04 AM.
The '7427 does not use a nuetral safety switch input.
What it does use is the gear select inputs to determine what gear the trans shifter is in. I don't remember the combination of on's and off's of those three inputs to detect what gear is selected, but I know it's in some of the EFI manuals from OTC and Snap On IIRC.
The man who says something is impossible, is usually interrupted by the man doing it.
On my '427 PCM schematics, A5 is Distributor Reference Low (Ground). I personally don't like the idea of grounding the P/N wire to Ground. On the '7747 to '427 PCM conversions I've done, I covered the P/N wire with heat shrink tubing and zipped tied the P/N wire to the harness.
The challenge I see to using a '427 PCM without a VSS is being able program which Spark / Fuel tables (Near Idle / Off Idle) for the PCM to use. I'm thinking without a VSS input, the '427 PCM will always think the vehicle speed is ZERO MPH. The '427 PCM could be programmed to switch from near idle / off idle, Spark / Fuel tables by TPS% only? I've never tried using TPS% only programming on the '427.
dave w
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