Engine loses power around 5000RPM

[HP2]

You could check them with an ohm meter before dropping the coin.

[Jacksboys]

You could check them with an ohm meter before dropping the coin.

Okay, I have an ohm meter.  What kind of range am I looking for?

[Chryco Psycho]

Regular carbon core should be 10-20,000 ohms , spiral core will be much less

[hemiken]

When you are driving the car and get to 5000 revs does the car feel like it is falling on its face and wont go any faster ?


If this is the case, it may be that your springs have gone off.

[Super Blue 72]

I have no idea what Honda products use but we used to ohm them out at 25,000 ohms.

So with what Chryco said (10-20,000ohms) and what I said, at the very worst, unless someone else can chime in, I wouldn't want anything past 25,000 ohms. 

[Jacksboys]

Regular carbon core should be 10-20,000 ohms , spiral core will be much less

Okay thanks   

I have no idea what Honda products use but we used to ohm them out at 25,000 ohms.

So with what Chryco said (10-20,000ohms) and what I said, at the very worst, unless someone else can chime in, I wouldn't want anything past 25,000 ohms. 

Good to know thanks   

When you are driving the car and get to 5000 revs does the car feel like it is falling on its face and wont go any faster ?

If this is the case, it may be that your springs have gone off.

It feels almost like it has hit a rev limiter and last time I drove it it felt like it skipped a little.  Either way the tach acts wierd at that RPM.  I doubt the springs are the problem, suppose to be good for a much higher lift cam.

[Super Blue 72]

Hey jacksboys, I was wondering what's the condition of the other ignition componenets like the ECU, ballast resistor, distributor?  Did you say you changed the cap and rotor?    Are they fairly new?  When you said it hits like a rev limiter, I was thinking ignition stuff.

[Jacksboys]

Hey jacksboys, I was wondering what's the condition of the other ignition componenets like the ECU, ballast resistor, distributor?  Did you say you changed the cap and rotor?    Are they fairly new?  When you said it hits like a rev limiter, I was thinking ignition stuff.

I am pretty sure it is the ignition but not sure what part yet.

The ECU is new, but I have a spare I might try at some point.  I got the distributor from my father, but it did the same thing on another distributer I tried first with a new cap and rotor, so I would not guess that is the problem.  The ballast resister is also new, but I may try that soon since they are cheap.  Otherwise I have no clue what it could be.   

I did notice that after the engine is fully heated and I have taken it for a long drive, the problem sometimes happens at a lower RPM, around 4500. Any clues?   

[HP2]

Do you have a vented distributor cap? If not, you might consider drilling some smallish (1/8") holes in at least four places around the cap, above the rotor line. I seem to recall something in the Engine book about the build up of ozone in a dsitributor cap that can lead to spark scatter. The holes allow venting to relieve the build up. If nothing else, it is a no buck change that may or may not help.

[FJ5_440]

If it seems spark AND heat related, I would try that spare ECU.  BTW, If I were you, I would have a spare ballast resistor in the glovebox.  They are cheap, and walking sucks.

[Jacksboys]

Do you have a vented distributor cap? If not, you might consider drilling some smallish (1/8") holes in at least four places around the cap, above the rotor line. I seem to recall something in the Engine book about the build up of ozone in a dsitributor cap that can lead to spark scatter. The holes allow venting to relieve the build up. If nothing else, it is a no buck change that may or may not help.

I know it was one of the Mopar Performance distributors, but not sure on the vents.  I would rather not drill into a perfectly good cap.  Any other ideas?

[Jacksboys]

If it seems spark AND heat related, I would try that spare ECU.  BTW, If I were you, I would have a spare ballast resistor in the glovebox.  They are cheap, and walking sucks.

When I get some more free time I will try the ECU.  I have been planning to get another resistor for a while.   

[Super Blue 72]

When I get some more free time I will try the ECU.  I have been planning to get another resistor for a while.   

As you may already know, make sure that it is well grounded. 

Will a regular local parts store cap work on a Mopar performance ditributor?  I think SB distributors that I've had in the past had a little vent built into the top of the cap.

HP2 raises a good point about spark scatter.  Not all caps are created equal.  My friend has an MSD distributor on his Shelby Cobra and he had a lot of corrosion issues from his cap not being vented and condensation forming inside.  He picked up I think a regular Motorcraft cap and his problem is solved since the new cap was vented.

[Jacksboys]

I will try to double check the cap for a vent this weekend.  I have just been really busy this week.

[MEK-Dangerfield]

I'm sure it's electrical, but this can be maddening.    It could be something as simple as an old original wire having higher resistance than it should, or a connection that is a little loose, or has some corrosion. I'm sorry I can't suggest anything at this point.   


   Mike