6200 RPM Redline?

[SHOspazz92]

Long story short, My fathers SHO is only shifting at 6200 RPM. He doesn't get on it all the time, However he said now it's only shifting at 6200 As opposed 7,000 or so.

No CEL's, Stalls, Sputters - Runs smooth as always.

It's a 95 ATX, 50k on a Rebuilt engine, 70k or so on the Tranny with a trans-go kit.

Any suggestions?

-Sam

 

[hawkeye18]

I think it's still shifting at 7,000 rpm. I think the tach is just getting inaccurate like they all are. Mine says I shift at 6,600rpm when in reality I'm shifting at 7,450. What speed is it shifting at?

 

[SHOspazz92]

I think it's still shifting at 7,000 rpm. I think the tach is just getting inaccurate like they all are. Mine says I shift at 6,600rpm when in reality I'm shifting at 7,450. What speed is it shifting at?

Not quite sure, I'll ask him.

Also, He said that he tried shifting Manually up to redline to no avail.

-Sam

 

[zblackbeast]

Does it go to fuel cut off at 6200? If so that probably means the tach is off.. Im surprised he only noticed it at WOT..

 

[1993MTXSHO]

Listen to the secondaries and see when they kick on. The computer commands them open at 3950 stock, that should tell you about how accurate the tach is about half way up. Also bounce that biznatch off the rev limiter too, the tach should be over 7k (just not long or say bye bye alternator). Also like hawk said, at 7k that thing should be at about 50mph, that should be a good indicator of how accurate it is too.

 

[38SHO]

or for the more adventerous redline in 2nd manually holding it out is about 90mph

this seems wierd, all my tachs have been pretty accurate I'd say

 

[1993MTXSHO]

or for the more adventerous redline in 2nd manually holding it out is about 90mph

this seems wierd, all my tachs have been pretty accurate I'd say

Same here I suppose we're lucky, all of my sho's always had very accurate tachs.

 

[SHOspazz92]

6200 @ 42 MPH

6200 @ 80 MPH

Those are the shift points for this car at WOT. Sounds to me like the Tach is accurate? Any other suggestions?

-Sam

 

[SHO Continental]

I had a bad VSS on my '93 a while back. Although it would do the opposite of what your dad's is doing. I'd shift it manually early and it would wait until redline to shift. Changed the VSS and it would then shift when I shifted it.

 

[Shoaz]

this seems wierd, all my tachs have been pretty accurate I'd say

IIRC the tachs are electronically driven and there's not much that would cause them to be inaccurate without outright failing.

In an MTX in fourth gear the tach and speed needles track in parallel. Don't know whether there's a corresponding mode in an ATX.

 

[St Louis SHO]

IIRC the tachs are electronically driven and there's not much that would cause them to be inaccurate without outright failing.

In an MTX in fourth gear the tach and speed needles track in parallel. Don't know whether there's a corresponding mode in an ATX.

Depends on who built the clusters that day. I've had several that were off by more than a few hundred. But they were only that way above 5k.

- James

 

[hawkeye18]

my tach is accurate to within 100rpm under 4K. Above that, it gets progressively lower until it's almost 1Krpm low at 7,500.

 

[SHOspazz92]

Depends on who built the clusters that day. I've had several that were off by more than a few hundred. But they were only that way above 5k.

- James

According to my digital tachometer, the stock tach in my 92 can be off by as much as 600 when the rev's start climbing.

-Sam

 

[SHOspazz92]

I had a bad VSS on my '93 a while back. Although it would do the opposite of what your dad's is doing. I'd shift it manually early and it would wait until redline to shift. Changed the VSS and it would then shift when I shifted it.

So, Your thinking VSS? Does this somehow dictate redline on a ATX? This car will not go past 6200 RPM in any condition.

-Sam

 

[SHOspazz92]

Bueller.....

-Sam

 

[hawkeye18]

I think that means we're all stumped. Are you sure there aren't any codes?

 

[SHOspazz92]

I think that means we're all stumped. Are you sure there aren't any codes?

Not in CA to run any and my dad doesnt have the time. He'll probably just end up taking it in to our local SHO mechanic of 10+ Years like he always does.

-Sam

 

[SHOspazz92]

Dad just called me. Said the car is back to Normal. Weird!

-Sam