Recent content by Ajrothm

I’m following along closely Bob. About to pull the trigger on a 4L80e from a local race trans builder… he’s got 4L80s running 5.0s@138+ in full auto mode and still using lock up. I know we’ve messaged about the details of the swap before, so I’ll be diving into this soon. I just installed...

No one stocks new or even reman cam sensors any more. I just went through this myself. Either send yours to someone and have it rebuilt or find an NOS one.... I managed to find an NOS Delco sensor and it cost me dearly. I had to ship to it from Canada to Tx to get it.

First I marked the sensor base/rotor so I could put it back in the same spot without the light tool. Next I pulled the base out and spun the shaft and noticed the rotor thing was WAY out of shape... I removed the rotor, “straightened” it and reinstalled, spun it etc. Reinstalled it...

Man...you called it. Let me post up my findings for the group.

Here is the base of the sensor. This was new in 2016. Has maybe 3-4K miles on it. Grabbing the “rotor” and trying to move it, it’s very tight. No play at all. Wondering if I should try to move the base a little in either direction and see if it changes anything....? or just order a new cap...

Cam sensor cap has a groove cut in it from the “rotor”. Not sure if that’s normal but I doubt it. I cleaned the cap and reinstalled it. Car instantly misfired again. Pull over, disconnect the sensor and the car runs fine. The “rotor”/shaft have no noticeable play in any direction. Would this...

I have not, but I’m about to mess with the cam sensor as unplugging it stops the misfiring.

So it’s something with the cam sensor. I can disconnect the cam sensor and drive it and it doesn’t misfire at all...as soon as I have plug the sensor back in and start driving again, it instantly starts the misfire. I tested this 3 times on my test loop and never even shut the car off. so...

Turbo is a 6266 and a FMIC. This misfire occurs at low load, way before it starts to build boost. I’m around -8” vacuum when I start to feel it misfire/studder.

I don’t have a powerlogger (yet). I would think If the MAF signal wasn’t dropping out, I would see a lean spike or something on the wideband? When this misfire/studder occurs, the afr is 13.9-14.3 range and cruising in closed loop(I believe). It runs good in this afr range while normal...

I haven’t tried driving it with it manually in 2nd but....I can get it to misfire in 1st gear at the same load range too so... my converter only locks in 4th at about 50 mph. It’s very distinct when it locks.... it locks hard. (5 disk Vigilante). This misfire is definitely “load” related...

At the time the misfire occurs, the AFR is steady in the 13.9-14.3 range, no spikes or rich dips. Definitely does not appear to be fueling related. “Feels” like an ignition misfire. Almost like when you develop a crack in a plug or get a slightly burned/arcing wire... just quick...

The coil pack, module, cam and crank sensors were all replaced with AC Delco units back in 2016....has about 3-4K miles on everything. I changed plugs and ohmed out the spark plug wires yesterday and all were under 100 ohms. I suppose it could be a coil or module, but I would think it would...

Hey Guys, can I get some help on diagnosing a low load misfire condition.? I know this will be a stretch but, here is what I have. New GN I just bought, I’ve put 100 miles on it. I don’t think I noticed this condition originally, however it has to be at a certain throttle position/load range to...

WTB: 86-87’ Grand National, HARD TOP only. Looking for a NICE, well sorted, built to mildly built car. Not looking for a full on race car, but also not looking for a low mile garage-Queen virgin either. No project cars. Must have working HVAC system and prefer everything on the car to work...