High RPM

JDZ-64

New Member
Joined
Sep 12, 2022
Hello everyone...

First time posting, I have been reading some of your post on this website and you guys really know what you are talking about. Anyway I am having an issue with my RMPS and I hope someone can help ... I start my car and the RMPS go really high for a while then within a couple of minutes they do come back down, but here is my issue while driving the car at 25 miles per hour my RMP are hitting the RED BARS... I never had this happen before does anyone have any idea why this is happening?
I have attached an image of what I am referring 2 ( 1987 Grand National )
 

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We need more/better info.

Do you have any other means of monitoring RPM's other than the LEDs on the dash? Scanmaster or tachometer for example?

I'm interpreting your post two different ways:
-Why is my dash showing high RPM's when the engine isn't actually at those RPM's
or
-is your engine actually idling at a very high RPM when you initially start it and in your picture your driving around bouncing off the rev limiter?
 
Agreed. If you haven’t had your boost/tach gauge recalibrated disregard. Casper’s does this service.

You need a more accurate way of telling engine RPM’s. Actual tach, Scanmaster, etc. The LED display was never very accurate even when new.

Plus I’m pretty sure you’d be able to tell if you’re spinning almost 6k at 20 M.P.H.
 
Hi mblum and " 87 Turbo T "
Thanks for replaying to my post I really appreciated, I do not have any other way of monitoring the rpm except for the LED on the dash.. I guess what I was trying to say in my post is that whenever I am driving the car the rmp are constantly high just like the pic I provided even at 20MPH is reaching 6k. So do you guys think that a Scanmaster is the way to go to really see what's going on ?
 
A Scanmaster at the minimum. The LED's again are notoriously inaccurate.

A Scanmaster will be able to give you a lot of information so you can tell what's actually going on.
 
A scanmaster is a must in my opinion, even if you don't have intentions of modding the car. It is a valuable tool to get and keep these old engines running to their potential my means of monitoring what multiple system critical sensors are showing. It will remove the bulk of the guessing when troubleshooting.
 
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