Strange issue.

[SuzukiGhostRider]

So I bought an '88 Beretta GT a few months back that had been sitting for awhile, but the engine is a '90 3.1L MPFI with only a little over 2,000 miles on a COMPLETE rebuild and all new externals/internals and accessories. Guy I bought it from had the receipts to prove it and you can tell. Shortly after getting it and changing the oil, etc. I started DD'ing it. It ran fine for a week or two then one day just shot up to almost full hot. I pulled over let it cool, checked it out. Fan was working, t-stat acted stuck. Put a new 195* T-stat in it, same issues. Running warm though not full hot. Maybe 3/4 of the way up the temp gauge. So I flushed the sytem.....TWICE. Radiator is new, t-stat is new, oil change is fresh, hoses are new, I replaced the water pump with a brand new one. Heater core is good to go as well. Heat and A/C work great , no leaks or clogs. I even hosed out the fins on the condensor and radiator, just in case. Now I haven't pulled the rad and done a reverse flush with a garden hose. Short of that and pulling the heads I'm at a loss. No oil in my coolant or vice versa. I have burped it several times and seen bubbles coming into the overflow almost every time. I'm starting to wonder if it's a headgasked compression leak.
NOW....here's the rub. The faster I go , the more air gets pushed over the Rad, the faster it should cool right? Wrong. Not with this car. The faster I go , the HOTTER it gets. Slowing down to under 45 MPH or under cools it down. With this in mind, and the fact that the last two weeks I'm noticing after the engine is warmed up my Oil Pressure is dropping to zero at idle in gear, I'm starting to lean towards a weak oil pump. My pressure is good cold, and as soon as I hit the gas AT ALL when it's warmed up , say from a stop light, the oil pressure jumps right back up. I had thought a bad sending unit as it randomly pegs full out for no reason , stays and then goes back to working. I'm thinking weak oil pump because if not enough oil is getting to the lubricated components, then going faster resulting in higher operating temps makes sense. I think I'll put a high flow in it. 20% more flow than stock. Also, I pulled my PCV filter and I see very little oil flowing through the valve covers. I've stopped driving the car until I get the pump replaced at the least.
I should note I started running a solid grill just before the first incident. I took it out and started running an 'egg crate' Beretta grill which is basically the same as no grill because it lets TONS of air through.
I need some help here guys. Don't know if you would need it, but here's a shot of the engine bay. 2.8 Upper Plenum on a 3.1L. Guy I bought it from said he did that for a "sleeper" effect,lol. But I ran the block casting ,head and LIM numbers. They all came back to a '90 3.1L.

[Money pit Beretta]

Hi SGR! Man, you and heat, what's the deal? Yea, from what you said it sounds like a oil problem. Just checking, did the guy that rebuilt it put a new oil pump drive in? Yes, I know that's always what I ask or think that's what it is. I lost a new water pump one time because I didn't put lube in, but it did work for a short time. Are you sure about the high flow oil pump? Stock GM should be ok, don't want to push the oil past the mains too fast.

[Money pit Beretta]

Anything new?

[SuzukiGhostRider]

Nah, car has been sitting for some time. Haven't had time to mess with it , unfortunately. I'll let you guys know when I can how it went. Thx for the ideas Money.

[Money pit Beretta]

Sure man, I'll be here if you need any other ideas. Are you going to change the sender first just to be sure?

[SuzukiGhostRider]

Yea, I'm gonna throw a mechanical on there to just to get an accurate read before I do. Then I'm putting the High Flow oil pump on just because it's a good idea. Give me a chance to glance at my bearings sort of while I'm down there. Then a flush to the Radiator itself, a new Rad cap,a 180* T-stat and a hard wired toggle so I can either run the fan constant or let it run by itself. If none of that helps, it's time to pull the heads.

[Money pit Beretta]

Sounds like a good plan SGR! I be looking here fo new posts.

[Money pit Beretta]

Update SGR? Let me know what's going on.

[SuzukiGhostRider]

Nada. Had little time to work on it. Been driving it very little as well. All those "I've been sitting neglected 2 years" problems are really starting to shine now though. I recently developed a miss at idle and since the plugs and wires are new (just replaced them less than a month ago) and I checked them out, I moved on to the coil packs. All test out fine, but it's number 3 cylinder with the miss. Middle coil pack. I'm guessing ICM is bad. Sux.
Also, pulled the IAC, and the amount of carbon on it was ridiculous. I'm guessing the moron that rebuilt the engine never cleaned the UIM , LIM , or TB. Doesn't look like it. Ran a can of Seafoam through the entire thing and cleaned the IAC, but it's still sticking. Gonna have to replace it , the CTS, possibly the O2, and probably the ICM. If I have to replace the ICM, I'm also putting brand new high performance coil packs on it. They run $60 apiece,but screw it.

Thx for checking in on me MPB.

[Money pit Beretta]

Sure man, I just have to know what's going on with you. What brand of coils? Man, I got some MSD coils and their made in China now.  Yea, I need to do some cleaning in the TB area also. The last owner just drove it, not that I didn't do that with the 90GT for 4 years. Hey, just let me know when you want those Moog control arm bushings(if you want to get something better don't feel like you have to take them). That guy... how can you rebuild an engine and just not care about anything else? I'm an all or nothing kinda guy though.

[SuzukiGhostRider]

Yea, right? I agree on the engine rebuilder. He's a tard. Guy I bought the car from stopped using him too.
Ya, I'll take those bushings dude. I'll pm  you my mailing address. Thx again bro.

On the coils, they're Accel. Staying away from MSD anymore for several reasons. The Accel's are $57 apiece.

http://www.autozone.com/R,APP11....ail.htm

[Money pit Beretta]

I would have got those if I knew that the MSD's were made in China. Accel coils are made in Mexico, I'd take that over China junk(too late now). Man, they were back ordered for three months also.