Re: 88 2.8 Corsica rough idle hesitation pinging
Posted: Wed Jan 22, 2014 3:07 am
Not to mention the extreme PITA of having to deal with the front mount bracket. Of course, now you can just buy them from someone for ~$150 (or less 
, but I am tired of offering that).
If you do decide on going for the 3X00 top-end swap onto your car, there are a few things I would recommend.
First, tap the water-pipe outlet for the heater core (at the back of the lower intake manifold near the thermostat) for the 2.8/3.1 quick-disconnect fitting -there is a recent thread where I've mentioned this to another member too, and it will save you some welding/fabrication work. Those disconnect fittings are available brand new for pretty cheap, which is good because it is almost impossible to remove them in one piece).
Second, be sure to get the power-steering pressure line (if not the entire pump assembly) from the donor car, those steel lines are a PITA to re-work, and the line from the 2.8 will not fit a 3X00 manifold correctly.
Third, be sure to buy either the Dorman steel LIMG set, or the Fel-Pro steel set -do NOT buy the plastic $#!t that has been pawned-off on us, as it melts, cracks, deforms, etc, and risks dumping coolant into your oil thereby damaging or destroying the entire engine (the 2.8 and 3.1 MPFI V-6s never had this problem, as GM didn't realize they could save a nickel on this part yet, and the clearances between the heads and the LIM are much smaller on the older engines too). Victor Reinz makes a steel set too, but I've never seen their set (yet), but I know the other two makes are good quality and do the job right.
Fourth, I'm not sure what you will have to do with the push-rods, as the MPFI engines have the shorter non-roller lifters, and any 3X00 engine worth using the top-end from will have roller-rockers (instead of pivot-ball, like the 2.8/3.1 MPFI and earlier 'M' code 3100s), but let us know what you've found that works if you decide to go this way.
You will definitely feel a performance difference with a newer top end though (I actually built my '90 turbo 'Retta backwards to this, because I wanted to keep the 3.1 LG5 turbo intake manifold, for style rather than performance, and wasn't worried about the older restrictive intake/heads because, well, it is a turbo-charged engine and works well enough for me with forced induction and a decent port-matching job). Have fun, and keep us posted!
, but I am tired of offering that).If you do decide on going for the 3X00 top-end swap onto your car, there are a few things I would recommend.
First, tap the water-pipe outlet for the heater core (at the back of the lower intake manifold near the thermostat) for the 2.8/3.1 quick-disconnect fitting -there is a recent thread where I've mentioned this to another member too, and it will save you some welding/fabrication work. Those disconnect fittings are available brand new for pretty cheap, which is good because it is almost impossible to remove them in one piece).
Second, be sure to get the power-steering pressure line (if not the entire pump assembly) from the donor car, those steel lines are a PITA to re-work, and the line from the 2.8 will not fit a 3X00 manifold correctly.
Third, be sure to buy either the Dorman steel LIMG set, or the Fel-Pro steel set -do NOT buy the plastic $#!t that has been pawned-off on us, as it melts, cracks, deforms, etc, and risks dumping coolant into your oil thereby damaging or destroying the entire engine (the 2.8 and 3.1 MPFI V-6s never had this problem, as GM didn't realize they could save a nickel on this part yet, and the clearances between the heads and the LIM are much smaller on the older engines too). Victor Reinz makes a steel set too, but I've never seen their set (yet), but I know the other two makes are good quality and do the job right.
Fourth, I'm not sure what you will have to do with the push-rods, as the MPFI engines have the shorter non-roller lifters, and any 3X00 engine worth using the top-end from will have roller-rockers (instead of pivot-ball, like the 2.8/3.1 MPFI and earlier 'M' code 3100s), but let us know what you've found that works if you decide to go this way.
You will definitely feel a performance difference with a newer top end though (I actually built my '90 turbo 'Retta backwards to this, because I wanted to keep the 3.1 LG5 turbo intake manifold, for style rather than performance, and wasn't worried about the older restrictive intake/heads because, well, it is a turbo-charged engine and works well enough for me with forced induction and a decent port-matching job). Have fun, and keep us posted!
-I don't think the 3400 valves are so big that they will interfere with the cylinder walls... Other than that, just go over what I already mentioned in my previous post -the push-rods are your biggest concern. Oh, you will probably also have to modify your throttle-cable linkage. Simplest way is to get a '95-'96 Beretta/Corsica throttle cable and 3100 throttle-body, and re-use the throttle-plate shaft on the 3400's throttle-body. And you will either have to block-off your EGR system or buy/build some sort of adapter for it. Also, being a pre-'90 car, there are some issues with your fuel-lines (3400s use GM's quick-disconnects, '89 and older L-Bodies use O-ring double-flared fittings). You cannot use a 2.8 injector-rail on a 3400 LIM, just be sure to keep your original injectors if you are not updating the ECM too. See? what questions could you possibly have... It is a piece of cake. 