Tach wont read past 2k RPM

[jtrakel]

Hello as the title states my tach will not read past 2000-2200 RPMs. It seems like it ready correctly while cruising and idle but stops right around 2-2.2k. I went ahead and gave it full throttle with my quad logging at it shows it actually going to ~3200RPM with the audio sound of it hitting the limiter. Is my gauge cluster just bad or am I looking at something more in-depth? 

 

In my long quest of fixing this truck i'll be replacing the VP and injectors in the upcoming week and want to ensure I don't have a ECM/PCM issue possibly. I've considered removing them and having them sent off for testing but I'm not getting any check engine lights or codes that i'm aware of, not sure if they can do much without having codes to provide when sending the unit(s) off for testing.

iQuad-2020-06-11-12.11.44.csv

Edited June 11, 2020 by jtrakel

[Mopar1973Man]

 

[jtrakel]

On 6/11/2020 at 4:40 PM, Mopar1973Man said:

 

 

I went ahead and conducted this test thanks for the link. First time around everything seemed to check out but I decided to do it again just because and look at the "wait to start light". I've never had an issue with my light not being on while starting the truck so never put thought into it. But during the test sure enough it wont illuminate.

 

 

@Mopar1973Man do you think this will point towards a replacement of the instrument cluster or something different, my Quad and code readers RPMs are withing a 100 or so of each other which are consistently 500-1000 RPM higher than whats displayed on the tachometer. 

 

[Mopar1973Man]

17 minutes ago, jtrakel said:

do you think this will point towards a replacement of the instrument cluster or something different,

 

Might be either... Don't know till I get error codes back from you. Module Master in Moscow, ID do rebuild the clusters for good price. 

 

18 minutes ago, jtrakel said:

Quad and code readers RPMs are withing a 100 or so of each other which are consistently 500-1000 RPM higher than whats displayed on the tachometer.

 

Just dumb things to ask. Did you check the cam sensor? Cam sensor wiring? 

 

Is the right ECM installed for your model year of truck? Some replace ECM willy nilly and end up having the wrong software possibly.

[jtrakel]

Just now, Mopar1973Man said:

 

Might be either... Don't know till I get error codes back from you. Module Master in Moscow, ID do rebuild the clusters for good price. 

No error codes are being reported from any controllers that I can see (ECM/PCM, or other doing the instrument cluster test)

 

Just dumb things to ask. Did you check the cam sensor? Cam sensor wiring? 

I've recently replaced the CAM sensor while troubleshooting other issues (my stutter discussed in other posts). I'll look at the wiring more when I pull the VP. I'm going to swap the crank sensor as well.

 

Just now, Mopar1973Man said:

Is the right ECM installed for your model year of truck? Some replace ECM willy nilly and end up having the wrong software possibly.

I would hope I have the right ECM installed but who knows with this rig. Is there any way to know if I have the wrong ECM and software installed? Maybe that could answer why I'm unable to read more codes between the ECM and PCM as I get the P1693 but nothing else no matter what I try. 

 

[Mopar1973Man]

 

1 minute ago, jtrakel said:

I would hope I have the right ECM installed but who knows with this rig. Is there any way to know if I have the wrong ECM and software installed? Maybe that could answer why I'm unable to read more codes between the ECM and PCM as I get the P1693 but nothing else no matter what I try.

 

Maybe... The problem would be having to send both off ot place like @Auto Computer Specialist to verify the softwares. They would test them both and tell you what is needed to repair them properly.

 

5 minutes ago, jtrakel said:

I've recently replaced the CAM sensor while troubleshooting other issues (my stutter discussed in other posts). I'll look at the wiring more when I pull the VP. I'm going to swap the crank sensor as well.

Ummm... 2001 Dodge doesn't have crank and cam sensors. Only Cam sensor. This means the engine has been swapped. Unknown if the engine and ECM and PCM are all matched. 

[jtrakel]

2 minutes ago, Mopar1973Man said:

 

 

Maybe... The problem would be having to send both off ot place like @Auto Computer Specialist to verify the softwares. They would test them both and tell you what is needed to repair them properly.

 

Ummm... 2001 Dodge doesn't have crank and cam sensors. Only Cam sensor. This means the engine has been swapped. Unknown if the engine and ECM and PCM are all matched. 

Thanks good to know, guess I wont actually need the crank sensor then! I just assumed it had one as well as the cam sensor!

 

I just sent a message to Auto Computer to start seeing what they may be able to do for help.

[Mopar1973Man]

1998.5 to 2000 had both cam and crank sensors. 

2000 to 2002 had just cam sensor. 

 

Tone wheels are very different between the two designs. The early is just a single tooth on the cam then a tone ring on the actual crank. This ended in 2000... 

 

Then starting in 2000 was the change over to a multi-tooth ring on the cam gear and move the cam sensor inward towards the hub of the cam gear. When you look at wiring diagrams the crank sensor was only moved to the cam. The cam sensor was deleted. The tone ring on the crank deleted.