1989 2.8 to 3400 swap

[Bake82]

Hey guys,

 

Thinking of swapping a 3400 into my 89 cutlass. Car is currently a 5 speed and will retain it. I am uncertain what needs to be done. I've searched and haven't found very much. So either I suck at searching(possible) or it's not well documented.

 

Here is what I know.

 

clutch and flywheel from my 2.8 will bolt up to the 3400

Injectors: I'll either need to use my old ones, or re-wire for the ones from a 3400.

ECU: if I run 2.8 injectors, I can get away with the stock 2.8 ECU/chip. If I swap to 3400 injectors I will need to be tuned for 3400 injector(was going to talk with ben WOT-Tech)

 

 

Here is what I am wondering:

 

What engine mounts and brackets will I need? Will I need to grab them all from a 3100 95-99 monte carlo?

Alternator: I believe they use different plugs, and I will need to re-wire this? or can I bolt up my 2.8 alternator?

Are there any other sensors that I will need to re-wire or change position?

 

I am currently looking at a 3400 from a 2003 Impala. Is there a better year range to try and choose?

 

Thanks in advance!

Edited April 27, 2014 by Bake82

[RobertISaar]

i wouldn't run the stock calibration regardless of what injectors you end up using.

 

yes, the alt plug is different for the CS130D, i just spliced a second alt plug next to the original one.

 

EGR: do you plan on keeping it or blocking it off? if you keep it, you'll need an adapter to stick the digital EGR pack on the newer manifold. if blocking off, calibration changes.

 

you'll want to grab a 3-wire coolant temp sensor and attach the connector for that into the wiring harness, reason being that the newer engines used a single, 2-wire coolant temp sensor, there is no provision for a guage sender. in the early days of OBD2, there was a 3-wire sensor used that combined both sensor and sender into a single location.

 

plan on swapping your existing knock sensor(or a new replacement for a 2.8/3.1, maybe even one for a 3.4), the OBD2 knock sensors are of the 100K impedence variety and won't function correctly with the OBD1 filters(which expect a ~3.9K impedence).

 

 

 

those are the only ones i can think of off-hand.

[Bake82]

i wouldn't run the stock calibration regardless of what injectors you end up using.

 

yes, the alt plug is different for the CS130D, i just spliced a second alt plug next to the original one.

 

EGR: do you plan on keeping it or blocking it off? if you keep it, you'll need an adapter to stick the digital EGR pack on the newer manifold. if blocking off, calibration changes.

 

you'll want to grab a 3-wire coolant temp sensor and attach the connector for that into the wiring harness, reason being that the newer engines used a single, 2-wire coolant temp sensor, there is no provision for a guage sender. in the early days of OBD2, there was a 3-wire sensor used that combined both sensor and sender into a single location.

 

plan on swapping your existing knock sensor(or a new replacement for a 2.8/3.1, maybe even one for a 3.4), the OBD2 knock sensors are of the 100K impedence variety and won't function correctly with the OBD1 filters(which expect a ~3.9K impedence).

 

 

 

those are the only ones i can think of off-hand.

I'll have a chip made and probably change over to the 3400 injectors.

 

EGR: yes I remember now reading about that. I'll block it off....so I need a chip anyways(should have thought of that before! lol.

 

colant temp sensor: I'll look into that and come back if I have any more questions.

 

Knock sensor: I did not know. thank you! I'll swap to the older one in(either new or used but i'll be the older style).

 

 

Are the motor mounts the same as a 2.8/3.1 and bolt in no issues? Just want to make sure all of the brackets that mount to the engine should transfer over or not need to be changed?

 

Thanks!!!

[RobertISaar]

rockauto is showing the lower engine mounts for the 2.8/3.1 as not interchanging with the 3x00s.

 

the 2.8/3.1 bracket looks huge, seems to wrap around the timing cover and oil pan to attach to the block while the 3x00 bracket is fairly compact and appears to attach to the oil pan.

 

 

 

maybe it will be more clear when the engines are next to each other?

[Heartbeat1991]

The 3400 mount bolts right to the bottom of the pan. I am sure there is a way to make it work. The timing cover isn't too much different.

 

The coolant sensor from the 2.8 can be used. You just need to drill a small hole in the head and put your gauge sender there. That's what I did. It was far easier.

 

In the end, I went to an OBD II system anyway, but it can run great without doing all that.

[Night Fury]

Very interested. Subscribed.

[Bake82]

For the lower mount I'll use the stock 3400 mount. I assume the upper mounts from the 3400 will allow me to use the dogbones from factory. If not i can get some made.

[Bake82]

But besides the alternator. Egr knock sensor and coolant temp sensor it sounds like everything else should work?

[l67ss]

I would use 95-99 3100 injectors myself, easier to dial

[19Cutlass94]

Better off with 3400 injectors. Gotta tune anyway so might as well use those. You'll run out of injector on the '95-'99 3100 rather quickly. As me and Saar found out.

 

 

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