DeTomaso Mailing List: March 2000, Message #257

Hi Russ
When I got my car it would go to 5400 then it was like rev limiter turned
on. The rebuilder had used weird tin plates to raise the intake and exhaust
ports. On the intake side It looked like the plates were trying to make a 2V
size runner. Unfortunately I sill had a 4V intake. It made a big shelf for
gas to puddle up on. It is a long shot on your engine but I mention it
because my car had a fresh rebuild when I bought it also. Perhaps you got
the same dumb rebuilder. Have you done a compression check?
Good luck,
Nolan Scheid
#2772


----- Original Message -----
From: Russ Jacobson <russj@enol.com>
To: Multiple recipients of list <detomaso@realbig.com>
Sent: Wednesday, March 08, 2000 7:22 AM
Subject: Help! Engine won't rev past 4600


> Hi All,
>     I would appreciate some advise.  When I bought #1363 the previous
> owner disclosed that the car would not rev above 4600 rpm.  He installed
> a new electronic ignition system from Hall and it didn't solve the
> problem.  The engine runs strong up to 4200 rpm where it starts
> missing.  It goes flat and sounded like crossfireing at 4600 rpm.  I
> bought the car anyway hoping to cure the problem with new wires and
> plugs.  Didn't work.  I took the car to a highly recommended shop to
> have them troubleshoot the problem.  They say the ignition system and
> carburation is OK.  After consulting with their machine shop they think
> the problem is burned valves or weak springs causing valve float.  The
> previous owner after installing the new Hall ignition without fixing the
> problem consulted with Hall.  Hall said if the new ignition system
> didn't fix the problem then it was probably valve float.
>
>     The engine was rebuilt about 10,000 miles ago with all new Crane
> parts including valve springs.  It now has a total of 37,000 miles.
> What I am wondering is there any diagnostics I can run to verify burned
> valves or weak valve springs?  Is there any thing else I should be
> looking to diagnose this problem?
>
> Thanks in advance,
> Russ Jacobson
> #1363 pushbutton
>
>
>