Engine Rev Limiter?

[Tommy]

Question: on a 87 GN with a 3.8 litre engine when I go WOT with the car at a roll at 20 to 25 mph and I pull back the gear selector from "drive" to low 1 is it normal that the engine cuts out?

But if I pull back the gear selector to low 2 instead of low 1 the car doesn't cut out, I'm assuming that GM put this feature in place so people don't over rev the engine? Any ideas on how can a person elimate this safety feature?

By replacing the computer chip with an performance upgrade will this answer my question.

Thanks

 

[SHADOWII]

You don't show....

any mod's, so one has to assume you are running stock. The rev limit is 6250, if I remember correctly. Normal shift points are around 4800-5400, and most 25 year old engines have worn out valve springs. which is one reason, it is recommended first to change out the valve springs when mod'ing. the valves can float and lead to disaster, not to mention the transmission life is going to be shortened.
The new chip can raise the limit, but not recommended w/o supporting mod's.

 

[Tommy]

Hello Shadow II, thanks for your reply. I don't know much about the Buick Turbo engines and the car that I have has only ~12,000 miles and is stock.

How I came across this in my car is trying to race a mustang on a "roll" going about 20 to 25 mph. I had the car in drive and when we counted to 3 I down shifted the car to 1st and that's when I noticed the tach stuck at ~4500 rpms and the engine sputtered and bogged as if there was a spark limiting feature in the ECM.

I then tried it again but this time only dropping it to 2nd gear and this time there was not sputter and the car accelerated nicely.

Any further thoughts on why this may be happening to the car?

Thanks for any information

 

[SHADOWII]

Sounds like ......

you have purchased one great car to have that few miles on it. Before you do any more thrashing on it, do a lot more reading. Too many guys have become dis-illusioned w/their car before getting to know the vehicle limitations. they blow a head gasket, transmission, cracked driver's side header, etc.
Have you ever heard the bible verse, "My people perish for a lack of knowledge." Well that holds true for these vehicles, they perish(parted out/bone yard specials) due to a lack of knowledge on the part of the owners.
Do a search in gn/ttype.org and ask a lot of questions if you can't find the answers in the "search" fuction. remember there is no such thing as a stupid question. We are all here learning from each other, as most of us have come from the chevy/ford/chrysler background.
You are going to make a lot of guys jealous when they see the lo mileage you have on that car!

 

[Phoneguy]

Get a scanmaster, upgraded fuel pump and hotwire, set your fuel pressure. Log your runs.

Head gaskets are a PITA to keep replacing...I would know! Good luck, welcome aboard.

Bryan

 

[CGASTON]

First of all, why are you trying to shift a bone stock car? Leave it in OD and let it run. You will get your best times that way. Only time you need to worry about shifting is when you upgrade to a T400. The 200r4 and ECM will do what you need. Continue to do what your doing and you can say good bye to that sweet 12,000 low mile motor. Your car, do what you will!