Alpha I drive giving false RPM's and then missing

[dwolter]

I have a 1998 Chaparral 21 ft with an Alpa I drive, 5.0 liter 225 hp EFI.<br />It began to miss three weeks ago at full throttle operation, but runs fine at lower<br />throttle positions. When it begins to miss I have noticed that the tach is displaying inacurate RPM's. It begins to miss, sounds like a popcorn popper at about 4500 to 5000 (falsly displayed). I believe that the ECU is involking the rev limiter when it does this scenerio. Can anyone provide me some insite on this?<br /><br />Thank you,<br /><br />Chap boy

 

[orca]

Re: Alpha I drive giving false RPM's and then missing

G'day. Dunno about the rev limiter, however these systems are really fussy when it comes to water in the fuel. they will run great at idle and slow speed however run rough at WOT. If you get any water in the injectors you will get problems.

 

[dwolter]

Re: Alpha I drive giving false RPM's and then missing

Whaley:<br /><br />I will try a new fuel seperator this weekend, hope that this will cure the problem. Do you have any other recommendations?

 

[karayj]

Re: Alpha I drive giving false RPM's and then missing

I hope Im wrong I had the same thing do a compression check on all cylinders for me it was a bad cylinder head....

 

[Trent]

Re: Alpha I drive giving false RPM's and then missing