PeteyPathy

@Rebel thank you for the info.

I chased every thread I could find that mentions owner manuals, only newer manuals are online appears, FSM wiring diagram doesn't tell purpose just where wires connect. No I won't bump start it unless i have to because of hyd clutch failure. Not only am I mechanic (the kind who turns wrenches for a living) I'm also CDL driver so accustomed to vehicles that don't have clutch interlock. I've owned several vehicles that clutch switch failed in so i just jumped it instead of replacing.

Can anyone tell me what the switch marked "INTERLOCK" on dash to the right of steering column, and below emergency flashers is supposed to do? When I push it the fuel light and brake light come on. Don't notice any other affect. Anyone have the original owner manual for an 87?

After some more thought on this one look for, any intake piping that are not seated correctly. Run your hand over or better yet separate and reconnect every junction. You may be suffering from whats called "unmetered air" make sure all clamps are tight and any hard plastic tubing is not cracked or split. Air entering intake system behind the MAF creates a lean running condition, basically not enough fuel for amount of air going in. ECU only provides fuel for air passing MAF. Any leaks computer can't account for. I have seen many cars drive owner crazy because of this simple problem. Good luck.

When buying sockets, if you can't afford or just don't want to invest in good stuff (Snap-on, Mac, Matco) then buy 6 point impact cheap-o sockets. Here is why 6 points grip entire head of bolt, instead of just the points the way 12 point does, meaning no rounded off bolts. Impact sockets are much more durable they won't break like cheap chrome ones do. Rachets, I second the prior post recommending biting the bullet and buying high quality rachet. There are several reasons first no one likes punching iron when gears in rachet break, second things become much more tedious when you no longer have a rachet, third (and most important to me) the action in a quality rachet is much lighter than in cheap o. Which means that bolt you can't quite get fingers on that is loose enough it just turns back and forth instead of working rachet gear, doesn't do that, or in some cases too tight for fingertips too loose for rachet. Top end rachet has much smoother action.

Double check that you haven't accidentally crossed up plug wires. Sounds to me like a timing issue. Sounds like at least 1 maybe 2 cyl are firing on wrong stroke. This will be less noticeable at higher RPM. Remember KISS! If last thing you did before it acted up was plugs and wires, 90% chance that's where problem lays. Or a wire you bumped/jiggled while doing plugs.

This sounds to me like probable ignition module. Very common symptom of ign module is to run 20 mins or so then die won't restart for 45 min to hour. Another common symptom is for it to run fine as long as you are maintaining rpms (on hwy or interstate) when rpms come down (red light or exit ramp) stalls out. If you have multi meter test coil first(easy to check before buying any parts) but ign module is my first suspicion. I'm new to Pathy, so am assuming they actually HAVE ign module. Every other vehicle from late 80's early 90's I've worked on had one on bottom of distributor so i feel confident VG30i is no exception. Good luck

I'm a mechanic for a living. I don't do double work if I can possibly avoid it do a little extra now save yourself trouble down the road. Redo is twice the work for half the pay.

Update, pulled upper water outlet, found bottom of gasket folded inside tube, actually had 2 cork gaskets and ton of RTV in/on joint biggest problem was PO appearantly lost one of the bolts and tried to replace with a standard thread bolt only went in about 3 threads before it got hard so they tried to fill in gap where wouldn't tighten properly. I ran thread chaser through, cleaned up, installed correct paper gasket, and put in correct metric bolts sealed up nice and tight, no more leaking or overheating. Some people really shouldn't be allowed to hold wrenches......

For those with VG30 engine or drive train mods, Gates Racing T251RB is a Kevlar belt 300% stronger than stock. I found this after I shattered an engine because my 2 month old stock timing belt popped under stress. Hope you guys find it helpful.

@kingman thanks. I'll see if i can work my bore scope in there and see what I see. Anyone have info regarding replacement for the Upper water outlet? I've checked rockauto, parts houses, even local dealership no luck on. I'll post where I find the timing belt at it sucks to loose a motor to hard driving.

I recently picked up an 87 pathy 4x4 VG30i overall really good condition, has persistent coolant leak, i say persistent because the PO obviously put some work into it. New radiator, all new hoses, gobs of RTV squished out of thermstat housing, and upper water outlet housing. I immediately went for thermostat, when i cracked it off and buffed the massive amount of RTV off i found sealing surface to badly pitted, and inside block to be full of rust mud! New thermostat housing easy at local parts house. Found small hole in thermostat bypass hose, replaced it. It has what i refer to as "cold" water leak, drips coolant from back of engine upon start up, when it comes up to operating temp can smell coolant but no drips visible. Question 1 can anyone tell me where i might find a replacement upper water outlet? Since poor thing obviously spent long time running on water instead of coolant i want to have new one on hand before breaking seal on old. Can't seem to be able to locate one though. Question 2 is it common for there to be coolant leak under the intake plentum. If so what other parts/gaskets might i need. Last VG30 i had never lost a drop. I plan to replace waterpump/timing belt very soon. Will be doing extensive coolant system flush at that time to clear rust out. Also does anyone know if they still make the Kevlar timing belts for VG30 i bought one years and years ago for 300ZX i used to have. Thanks guys