F41eatsFords

OK, so before I sold my 84 Camaro, I pulled the perfectly functioning cruise control for install into my 86 Camaro. Everything's hooked up as it was before exactly, but it's not working. I've tried holding down the accel switch a couple of times, and it feels like the pedal's trying to pull out from under my foot (pulsates), but unsuccesfully. throttle cab;e seems perfectly free/not binding. I've checked all electrical connections and they're not loose. I've pulled the small vacuum line at the vacuum TEE between the actuator and check valve after the car's been shut off a while and there's def a vacuum being held (loud hissing for several seconds after disconnect). I also clamped off the large vacum hose between the actuator (attached to the throttle cable) and brake switch, right at the actuator and drove around trying to set it to see if there was a leak on that end, but it still didn't work. All testing done at or over 40 mph. Any Ideas? I'm not sure how to test the electronics, other than I KNOW it was working fine before I pulled it out of the 84.

the 86 has the SAME ENGINE/TRANS as the 84; lg4, 700r4. The only real difference is that the 86 has been converted to mech carb and dist (no ECM). Is there any reason that the Cruise wouldn't work due to the ECM being deleted? Also, is there a difference between the Cruise systems between 84 and 86 which mights cause issues? Also, it there a way I could hook up the "speed reader" wire (red, connects close to Cruise Computer)(sorry, forgot the actual name) to the tach or something to see if it would work then?

Sorry if I've been rambling; Hope I'm making sense. I'm about to head to bed, and am a bit tired.

n1ffer

I had an issue where the cable that went into the cruise control unit had one strand broken and it was hanging up with the sheathing not allowing the cable to move within the sheathing. IIRC you can visually check this by moving the accelerator cable and watching the cruise cable to see if they are both moving.

F41eatsFords

I was wondering that too, since the plastic sheathing was cracked apart in one spot, but the cable still slides back and forth pretty effortlessly (manually pushed the diaphragm on the actuator and it pulled the throttle via the cable), so I tend to doubt it's that. Thanks, though.

I'd prefer to make sure that there was no change to the circuits connecting to the cruise control harness between years before I continue troubleshooting (aka, replacing parts or taking it to my mechanic) the components themselves. If anyone has info regarding this, I'd appreciate it. Thanks!

n1ffer

I think there was a change in the unit. I believe 1985, but not 100% sure. Not sure what the change was either.

Not much help, sorry!

F41eatsFords

I.m Gonna try JamesC's solution found here:

https://www.thirdgen.org/forums/engi...-function.html

IDK if that's the issue or not, but mine is missing the ECM, and the VSS ground hasn't been grounded like he suggested, so it's worth a shot. At least it's something to go on.

F41eatsFords

OK, so I routed the Black/White wire to ground from JamesC's thread (see above), and now the cruise is working perfectly. Just for further clarification, the wire I'm refering to is on the main harness, under the Pass side of the dash, and the connector (1 of 2) normally connects (I believe) to the ECM; either that, or the Engine harness. Mine are removed, so I can't remember off hand where it went to. Just look for the Black wire with the white stripe.

It just has to be grounded, either by splicing it into another ground wire like JamesC did, or ground it somewhere else nearby/convenient. I routed mine back to under the Driver's side dash to a ground point used for part of the harness, since I already have other devices grounded there as well. Again, this is for if you are missing the ECM and have a CLUSTER mounted VSS.

So, the '84 Camaro cruise control does work in the '86, and is as simple as plug-and-play if your ECM is still operational (at least on the LG4). If the ECM isn't operational, the only other step you need to take is grounding that wire, and you should be set to go. I'll also add, that though slightly tedious, I was able to remove the system from my old car and install it in the new one without removing the front dash panel on either vehicle. The only thing that needed removed (for me) was the top dash pad, and I undid the cluster and pulled it out slightly (left it connected) to give me a little more room to work. I just cut the clips holding the CC harness with side cutters to remove it, and used zip ties where I could fit my hands during install. That being said, it was maybe a couple hours each for removal and install, including trying to figure out what I was doing, so it could easily be done in an afternoon.

Next step, retrofit the A/C to get that working (after I install the Headers!)