I am swaping a 3800 series1 from a 92 Bonne into a 91Bonne which also has a 3800 series1. The only difference I see is that the 92 has a black colored intake and the 91 has a grey colored intake. Also the 91 has the computer chipped ign key, while the 92 has a regular ignition key. A local guy told me that the 92 engine might not start in the 91 because the ignition keys are different, But he was not sure. Does any one Know for sure If the 92,s 3.8 will run in the 91 Bonne with the chip in the Ignition key. If not would putting the regular ignition or whole steering column in the 91 solve the problem. Im stuck . I NEED HELP!

The 91 doesn't have the Series I 3800. It's actually an LN3 motor where the 92 is an L27. Do you plan on swaping the ECM as well? I have not researched the differences between the two but my guess is that you will have to swap them. If this is the case then you will have to bypass the VATS. According to my 93 diagrams, it only requires grounding one wire which is fuel enable input to the ECM. The other thing you might have a problem with is the srarter enable relay if the 91 is so equipped. I don't have a diagram for that year but it is probably just as easy to disable. You will no longer have an anti-theft system in the car though.

Thanx a million .I hate being stuck in the middle of a job. Your explanation makes much more sense to me. Im lifting out the old motor today. Ill let you know how it goes. Also Is there anyway I would be able to take a look at those diagrams you mentioned. A website ? A Manual? or if youve got time email me a copy at
fc_ent@yahooo. Thanx again

I keep getting returned mail notifiaction with your address. I tried it as-is and with .com on the end. Neither worked.

The 91 doesn't have the Series I 3800. It's actually an LN3 motor where the 92 is an L27. .
What are the main differences between engines? Mine is '93, listed as L27 too and I know this one has offset half-thows on the crankshaft to provide equal firing intervals. I think previous models were of the unequal firing type but did that go up to the LN3?....

I'm definately not the expert when it comes to the specifics but performance wise, the LN3 has a noticably milder cam. Physically, most of the 92 L27s came without the EGR valve but it returned in 93. In 87, the 3.8 (not sure of the engine code) was used in most of the Bonnies except for very late in the model year, 88-91 used the LN3 and 92 to 94 used the L27 for normally asperated engines.

I'm more electrically inclined with these cars rather than mechanically. That's why I was concerned with the ECM swap. I thought I had a link to more specific differences but I can't seem to find it. I'll keep looking though.

Interesting!

My mistake the e-mail is fc_ent@yahoo.com. Ive got stuck keys. Also theres an underscore after "fc" that gets covered by the link bar . But it should work now . thanx again.

LN3 Vin code "C" and L27 Vin code "L" were used in model year 91.

The problem the you will also run into is not only the VATS/ Passkey II system is also the L27 was a "quick fire system" and the pickup was different off the camshaft & cranksaft.

LN3 Vin code "C" and L27 Vin code "L" were used in model year 91.

The problem the you will also run into is not only the VATS/ Passkey II system is also the L27 was a "quick fire system" and the pickup was differentquick fire system off the camshaft & cranksaft.



quick fire system? What's the fix for that?

LN3 Vin code "C" and L27 Vin code "L" were used in model year 91.

Are you speaking of GM vehicles in general or specifically the Bonneville? I have never seen a 91 Bonneville with the L27.

Are you speaking of GM vehicles in general or specifically the Bonneville? I have never seen a 91 Bonneville with the L27.

Nope,
You're right the L27 was not available for this model year vehicle it was availble for the 92 model year (also built late in 91).

SGHETTO,
To get the L27 to work in the LN3 engine compartment, like Radman said, will require and ECM swap. Also the ECM for 92 will require an VATS/ Passkey II signal, the decoder supplies a ground for the starter enable relay and modulates a 5 volt reference signal (at 2.5 volts) from the ECM or PCM which will then pulse the fuel injectors.
If the codes do not match, the decoder module sets its internal timer which locks out starter operation and fuel enable for up to three minutes.
I think you can ground circuit 229 (92 ECM) and this will bypass the VATS/ PasskeyII system.
Good luck HTH

Walt