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Captain Dick

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Have twin 2007 injected Crusader 5.7 Captains Choice Engines in my 30 ft Tollycraft. The Stbd engine will only reach about 4200 rpm at WOT. There is no missing, rough running, etc., just will not reach the 4800 to 5200 recommended. Port engine is fine. Both engines run off same tank. All filters have been replaced, injectors cleaned, and new cap and plugs installed. Bottom has new paint and shafts and props were checked when boat was pulled about 2 months ago. Also, diver cleans bottom and running gear once monthly. Engines only have about 150 hours and compression checks were done when boat bought about 3 months ago. Fuel pump pressure has been checked and computer read for any problems. Any suggestions where to look will be appreciated. Thanx in advance, Capt Dick
 
welcome to ME.com!

how was the fuel pressure checked and what were the results? Ditto for the scan tool check?
 
More specifically, did fuel pressure meet specs underway at WOT and was cam retard adjusted to specs when the scan was made? If both of those are affirmative then I would try reversing the tach leads just to be really sure it is a performance problem and not a gage problem.
 
No VVT. But on the 5.7 MPI Captains Choice (at least on mine) the "cam retard" is just a poorly selected name for an important adjustment. Nothing to do with the camshaft. The timing is totally controlled by the ECM and driven off of the crank sensor. But you still can loosen and turn the distributer just like you are adjusting the timing. Getting the cap in the correct position is called "cam retard" for reasons that are obscure to me. It is important because the rotor is fixed to the distributer shaft and never changes position vis a vis the engine piston position. But the spark leaves the rotor at a time that advances by some 30 degrees (actually half that on the distributer rotation) as the engine speeds up. So the trick is to get the cap in a position such that the spark leaving the rotor and going to the plug wire post will not have to jump too far at idle or at maximum timing advance. In between it will be pointing dead nuts at the post for the plug wire. If the adjustment is off the engine will run rough at idle or if off the other way it will start to miss and loose power at high rpm. So it could be Captain D's problem.

When the scanner is set to "cam retard" on the 5.7 (engine running) the correct reading is 45 degrees plus or minus 2 degrees (as I remember, don't have the book in front of me). What I don't know is how in the heck the scanner detects exactly what the relationship between the rotor and the cap might be. But it does and a very, very small amount of rotation of the cap will bring several degrees of change on the readout. When you have it right you just tighten down the distributer bolt and the seems to hold the reading indefinitely.

Unfortunately, the "cam retard" reading requires a scanner (not a code reader) and except for some hot rod oriented scanners, only Rinda makes one for this engine.
 
Got it...got confused as I fixed a HHR engine this past weekend with a bad actuator and had references with it to cam retard and cam advance...

Agree, your context refers to the alignment of the distributor installation wrt the rotating assembly and the desired point shifts from 45 degrees to 2 degrees depending upon the specific configuration of the engine. If it is outside of the 4 degree window, engine performance will be limited.
 
But why is it called "cam retard" instead of "distributor alignment" or "cap position adjustment" or some other such descriptive term? No wonder half the owners don't know it needs to be adjusted.
 
I did a little digging and found out what we are talking about is more formally referred to by GM as "cam retard offset" and originated from the procedure for setting the distributors on the "newer" vortec engines (with distributors)....

Cam retard on these engines is fixed. using TDC as the reference point, the position of the camshaft is fixed. the distributor needs to have the rotor aligned within a certain arc to ensure delivery to the specified spark plug terminal. the "offset" is how the rotor position is measured, relative to the camshaft being it the referenced position.

Two concluding points - 1) I'd bet "Cam Retard" is used on the scanners due to a) GM reference literature & b) space limitations on the display and 2) proprietary data claims are usually protected (for a finite time) by obscuring the simple items - I'd bet this had a part in the naming, too.
 
@Mark - Hmm. Thanks for the info. You are probably right about how these things come about. Still don't think much of the name, and I can tell you do not either!

Also still interested in how the computer detects the relationship. I recall (vaguely) reading once that one should check it at 1500 (??) rpm. I check it at idle because I did not notice any change in the reading at 1500. But thinking about it, maybe it should (in theory) be checked at "half" advance if we are trying to get the cap centered. Wish I knew how the computer/scanner generates this number. On the other hand I have not had any high rpm issues so perhaps I should sit down and shut up.
 
makomark said:
I did a little digging and found out what we are talking about is more formally referred to by GM as "cam retard offset" and originated from the procedure for setting the distributors on the "newer" vortec engines (with distributors)....

Cam retard on these engines is fixed. using TDC as the reference point, the position of the camshaft is fixed. the distributor needs to have the rotor aligned within a certain arc to ensure delivery to the specified spark plug terminal. the "offset" is how the rotor position is measured, relative to the camshaft being it the referenced position.

Two concluding points - 1) I'd bet "Cam Retard" is used on the scanners due to a) GM reference literature & b) space limitations on the display and 2) proprietary data claims are usually protected (for a finite time) by obscuring the simple items - I'd bet this had a part in the naming, too.
Click to expand...

Okay, I don't want to steal this thread but does this apply to the 8.2 MPI Crusader engine as well? If yes I will post in a new thread my question.
 
You are better off starting your own thread since your diagnosis may be different and the famous "cam retard offset" is only one possibility in the case of Capt. Dick and his issues. Having said that I think the 8.2 MPI is fundamentally the same (Mark would know for sure). I believe it has an MEFI computer and you should download the diagnostics manual for the MEFI 4 or 5 (whatever you have) from the internet. It is the same manual as for the 5.7 but has separate sections (that I have not read) for the 8.2. Available for free or for fee if you search. And if you have a distributer on an MEFI engine then yes, the cam offset is something that must be set correctly. But the manual will give you a much broader list of possibilities for whatever is ailing you.
 
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