I swapped in another motor from an 89 camaro. Before I did the swap, my car idled fine. Now with this motor in, the car vibrates big time when idling and around the 1500 rpm range. I notice there's a hole in the top of my passenger side exhaust manifold (looks like it came from factory like that) and can feel some air coming out of there. I think i also have a leak on the same side where it joins the exhaust pipe. I swapped over my fuel rail from the old motor and most of the sensors as well. I put in a new Bosch O2 sensor. The only thing I didn't connect was one of the two wires that goes into the thing the oil filter screws onto. The new motor didn't have a connector for the one wire. Another thing I notice is sometimes when I decelerate the rpm will jump to 1500 before falling back down to around 500. Any ideas?

 

do you still have the old motor?????

hole on exhasut manifold--could it be for an air pipe? I never seen one on the thirdgens V6's

leak where it joins exhaust pipe-- recheck y-pipe flange, we don't need another car up in flames from that mistake

back to the "still have the old engine" thing-- swap the oil filter adapter (what the oil filter screws on to) from teh old engien to new. Then everything will hook up.

for vibration, did you reuse the balancer & flywheel/flexplate from teh 89 as well?

 

I still have the old motor. I did not use the flex plate from the new motor because it didn't come with one (i think it was a 5 speed, my car is auto). I just attached mine onto the back of the motor.

 

in 87 motors went to internally balance.

It is possible your "87" is still an 86 car. They build cars way ahead of time. YOu could have an external balanced motor.

Could be that your "87" flywheel was still externally balanced and you stuck that flywheel on an internal balanced motor, making everything out of wack and vibrate like crazy. Also it would ruin the motor over time.

It may be a PITA but I think you better drop the trans and make sure you have a neutral balanced flywheel on the 89 motor.

 

Yes, some V6's came with the AIR system, mostly they were cars with standard transmissions. However, some cars circa 1986-7 with auto transmissions also will have the system. GM put out a TSB regarding cold start hesitation and stalling for those cars having the 2.8 mated to the 700R4, and one of the fixes on the checklist is to install a different PROM that allows the fuel mixture to be slightly on the rich side of the ratio. To stay within emissions compliance, GM was forced to distribute the AIR system to cars that were fixed using the replacement PROM.

If you have an extra hole in the passenger side manifold, and you already have your EGR hooked up, I've heard that you will need a bolt with a 7/8-18 thread to plug it up, but since I have a check valve in mine, I don't have the hole plugged.

Also, GM did switch to a newer oil pressure unit around 1988-89 that is a one-piece, three-wire unit. If you want to use your gauge (the white wire... if you only put the one wire unit in the oil pressure adaptor you ain't going anywhere) you need to get the harness connector from GM (hard to find) and the proper switch (90-92 at any auto parts store usually gets you what you want) and install them.

 

Well, if he only hooked up the one-wire connector to the oil sending unit, he'd still be able to drive. The two wire is (of course) for the fuel pump switch, but the fuel pump relay would act as a backup and keep him running. I drove without my fuel pump switch hooked up for a long time! (When I installed my gauges, I unhooked the two-wire connector, thinking it was for the factory idiot light- oops!)

That's some great info about the AIR system tho!

 

Whats a "neutral balanced flywheel"?