5.3l, vss, & th400
Thread Starter
Teching In
Joined: Feb 2004
Posts: 39
Likes: 2
From: Austin, TX
5.3l, vss, & th400 I'm trying to get all my ducks in a row for a 5.3L swap into my '86 suburban.
This truck has the cable speedo TH400. As I understand it, the LSx ECM's look for 40 Pulse per rev sine wave signals while manuals are 17 per rev.
I've seen a couple of offerings for through the sensor adaptors to use inline with the original mechanical speedo cable. Ones that generagte a signal but still use the old cable. The VDO item, for example, is 16 pulses per rev http://www.egauges.com/vdo_indS.asp?...edo&PN=340-012
(no idea what the signal function is sine or square etc)
Jags that run offer a 4 pulse per rev
http://www.jagsthatrun.com/Pages/Spe...integralsleeve
I've also heard teh '90-'92 cop cars had some kind of factory cable & vss signal unit.
The VDO unit looks like it is pretty close to the manual trans reading, so it would seem there is plenty of adjustment in the ECM tune.
so, what is the most simple way to run a 5.3L using an older non-computer transmission? will the 16 pulse VDO unit work? JTR unit? Will both of these need ECM reprogramming to calibrate? If so, will one be a safer option as far as tuning ranges are concerned?
Are there better options out there?
for those that have swapped into TPI or TBI equiped cars and kept their original transmissions, how did you adapt for VSS? Original sensor with just a tune adjustment?
I'm trying to keep this simple & cheap. it will be a very tight budget swap. I'll really want cruise control, and since many of the available engines are drive-by-wire I will want to make sure this vss option works for those types of engines.
This truck has the cable speedo TH400. As I understand it, the LSx ECM's look for 40 Pulse per rev sine wave signals while manuals are 17 per rev.
I've seen a couple of offerings for through the sensor adaptors to use inline with the original mechanical speedo cable. Ones that generagte a signal but still use the old cable. The VDO item, for example, is 16 pulses per rev http://www.egauges.com/vdo_indS.asp?...edo&PN=340-012
(no idea what the signal function is sine or square etc)
Jags that run offer a 4 pulse per rev
http://www.jagsthatrun.com/Pages/Spe...integralsleeve
I've also heard teh '90-'92 cop cars had some kind of factory cable & vss signal unit.
The VDO unit looks like it is pretty close to the manual trans reading, so it would seem there is plenty of adjustment in the ECM tune.
so, what is the most simple way to run a 5.3L using an older non-computer transmission? will the 16 pulse VDO unit work? JTR unit? Will both of these need ECM reprogramming to calibrate? If so, will one be a safer option as far as tuning ranges are concerned?
Are there better options out there?
for those that have swapped into TPI or TBI equiped cars and kept their original transmissions, how did you adapt for VSS? Original sensor with just a tune adjustment?
I'm trying to keep this simple & cheap. it will be a very tight budget swap. I'll really want cruise control, and since many of the available engines are drive-by-wire I will want to make sure this vss option works for those types of engines.
Last edited by y5e06; Nov 11, 2009 at 11:34 PM.
Thread Starter
Teching In
Joined: Feb 2004
Posts: 39
Likes: 2
From: Austin, TX
yeah, the more I read the more it looks like the JagsThatRun 4-pulse inline sender is the most straight forward.
JTR sender & tune adjustment, done.
I'm trying to keep swap costs down and run my original TH400. If everything works out, I will eventually want a 4L80E swap too.... but buying sender and anything else on top of that goes in the cost-against column of keeping the TH400 for now.
JTR sender & tune adjustment, done.
I'm trying to keep swap costs down and run my original TH400. If everything works out, I will eventually want a 4L80E swap too.... but buying sender and anything else on top of that goes in the cost-against column of keeping the TH400 for now.
JTR also sells a differential mounted reluctor that outputs the newer 40 pulse per rev signal
That allows the factory cable speedo to be unaltered. For electric speedo cars, the PCM output can be used
That allows the factory cable speedo to be unaltered. For electric speedo cars, the PCM output can be used
