85 gn motor

[andrewrock5]

hi, i'm totally new here and not too sure how this works, but i have an 85 regal that we put an 85 gn motor in. however, i got totally screwed on the whole deal. the motor does not run well at all. i have all kinds of header leaks, and it makes the accelerator pedal vibrate, and it makes a knocking sound. any idea where or how much i can get new manifolds for? also when you hit the gas the battery light comes on and the car almost dies. i took it to a gm dealer and they told me that their computer could not read the computer in the car (we switched computers when we swapped motors) they said that i could possibly be running on the base system? i don't really think they know much at all about gn's...the manager there had never even seen one if that tells you anything. any help would be greatly appreciated. i don't really have the money to fix it all up and would actually consider selling the motor, it runs great, but it just has that exhaust leak and something going on with the TPS...(which i did change as well) any help is greatly appreciated!!!

 

[BRAD_PADGETT]

The header problem is easily solved. Post on the parts wanted section for stock headers that do not leak. This is a common problem. You can also upgrade to higher performance headers from Poston or ATR. (I am sure there are others). The passenger side header is the only one which needs to be upgraded for more horsepower. What kind of computer did you put in? What did the original car have as an engine? The 85 Buick Regals have carb V8 and carb V6 3.8. The 85 GN was fuel injected. Good luck Brad

 

[1bad84gn]

where's vienna mo at. i have a good set of headers.

 

[andrewrock5]

i am not sure what kind or type of computer that we put in it. the engine was actually pulled straight out of a 85 gn..so i'm guessing it's just the original computer from an 85 gn? the original motor was a 3.8 2 bbl carb motor that was in perfect condition until i let a school put a timing chain on it and they threw a rod in that motor...and refused to pay for the repairs...that is how the whole big miss with the gn motor started....both deals were really bad where people just took and screwed me over and i couldn't really do anything legally without getting into suing them. how could i find out what kind of computer was put in? thanks for the reply brad.

 

[andrewrock5]

vienna missouri is directly in the center of the state...bout 2 hours from st. louis and about 3 hours from kansas city. what type of headers are they? if they are factory, what year gn did they come off of? thanks

 

[1bad84gn]

headers

stock off an 84 gn

 

[turbobooster]

well if its a 2 b carb that u have in it now i dont think its an 85 like it was mentioned above earlier its gotta from 83 or older

 

[andrewrock5]

i apologize, the motor that is in it now is an 85 gn motor (fuel injected) the ORIGINAL motor that was in the car was a 3.8 2 bbl. carb motor. sorry bout that.

 

[andrewrock5]

how much are you selling those headers for? was there any problems with headers from an 84? i know that there was a "design" "flaw" in the 85's that was corrected in either 86 or 87. also i saw an 87 GNX today #547 or #546...only 1100 miles on it. i think he is asking something around $48K. (in case anyone might be dying to spend that much

 

[1bad84gn]

headers

let me check tomorrow & see i have a set of really nice ones & a set that have been fixed. do you need just headers or headers & x-over. also can you give me the info on that gnx a phone number & where it's at thanks jim

 

[andrewrock5]

jim that Gnx is totally original, bone stock. it has 1094 miles on it. it is #546. his name is scott, and his phone number is 913-780-5576. the car is located in olathe, ks (southwest KC) i checked it out today, and it still smells new!

 

[Dwayne]

did you take the motor wiring harness with the gn motor?

 

[andrewrock5]

yes we did take the wiring harness that was from the gn...we just transfered everything over and plugged all the wires into the computer.

 

[highboost]

i have a stock 85 t-type ecm and stock prom if it will help

keith

 

[racemybuick]

I too, have a stock ecm, and I think I also have the chip too! I have a set of headers that need to be welded, but are not cracked badly. Just one crack on each side, with the x-over attached. Welding the ones on your car already may be the cheapest route. They just need to be beefed up at the flanges. If you have a heaving knocking in the motor, then it is not just an exhaust leak. It can be a rod knock. Did you drop the oil pan? check your rods and the lower end? If not, I recommend it. Drop the oil pan, clean it out and check for metal shavings....Use a magnetto skim the bottom of the pan to check for the metal...if it picks up large pieces, or a lof of metal....you may be in big trouble! Also, check your belts and make sure they are nice and tight. If the battery light comes on, it usually means the car is stalling or fouling out...IE, poor fuel mixture is clogging up your plugs.

Did you replace anything on the motor before swapping? New plugs, new wires, new O2 sensor? These are all intrical parts to the car, and only 93+ octane fuel. As for oil, go with 10w30 to start, until you get it running right...Then I would switch to the synthetics....

If you did all the items mentioned above, it is time to get some monitoring tools.... A scanmaster 2000 can help greatly, a knock guage, a fuel pressure guage and all the other guages like water temp, oil pressure, boost, and a tach.

Get all these together, and get some numbers for the vitals. If you just swapped and started, you skipped a ton of necessary items, and you have to go back. Plugs, wires, air filter, fuel filter, and so on.

Another thing...Did you install an eletric fuel pump? How is the car being fueled? Do you have an adj fpr? Think about all of this and let me know!

Good luck!

John

 

[andrewrock5]

john,
thanks for all the help. i'm positive the knocking is not a rod....it almost sounds like my exhaust pipe is running or knocking on the firewall. we did change all the plugs, wires, o2 sensor, fuel filter, all of that stuff when it was swapped. it was myself and the guy that totally screwed me on the whole deal working on it. i knew almost nothing about swapping a motor...so i'm not sure what all could be lose under there....i'm pretty sure we tightend everything. i know i had to take it back because they forgot to totally tighten the bolts on the torque converter. (they just slapped it together.........for me...) i don't have any guages, except a water temp guage. ($$) i have been running premium fuel in it when it's driven. we did switch out the gas tanks with the one from the gn...it had the internal fuel pump on it....and you can hear it come on. i know that he sent the injectors off and had them redone or cleaned. so i'm not too sure what is going on with it...it's almost tempting to just sell that motor and put in a easy 350 or something?? what is a adj fpr? thanks,
andrew

 

[racemybuick]

adj fpr: Adjustable Fuel Pressure Regulator. You can buy them from Postons, kenne Bell, Dennis Kirban...If you look at your fuel rail, it is the thing that looks like a d-sized battery with a hose coming out the top of it on the driverside top of the intake. It is at the very front of the fuel rail. Without an adj FPR, you are stuck at the factory settings, and if your swap has any glitches, you may not get enough fuel, or too much! You never know. So, with that, get a fuel pressure guage, and an adjustable fuel pressure regulator from one of the big three listed above, and make sure that car has a pressure of about 42 ish at idle. I am pretty sure that is what everyone sets them at these days!

BTW, I think they sell for 85-100... Good luck!

John