Hard starting with radix 112! any ideas what is causing this?
11-08-2009, 08:55 PM
#21
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ALONG WITH THE ENGINE SOUNDING STARVED FOR FUEL THE SUPERCHARGER KNOCKS, if the engine fires and idles normal the knock instantaneously goes away. its just the first few seconds of the crank that it sounds like the rotors in the supercharger is going to come out of the case!
Is this any help?
11-08-2009, 09:28 PM
#22
2 separate issues, I'm sure. The SC knock is somewhat common, what is your cold idle rpm?
As far as the starting issue, I have tried a few things but to no avail, I don't recall when this started occurring but it wasn't after any retune....matter of fact I completely retuned and the problem has remained consistant. I'm thinking it's more of a mechanical (fuel pump?) issue but I don't see any issue with pressure.
As far as the starting issue, I have tried a few things but to no avail, I don't recall when this started occurring but it wasn't after any retune....matter of fact I completely retuned and the problem has remained consistant. I'm thinking it's more of a mechanical (fuel pump?) issue but I don't see any issue with pressure.
11-09-2009, 12:27 AM
#23
To me, both trucks sound like they have fuel delivery problems. To both guys, are these problems consistent(when cold, like parked overnight), or random? To both guys, when you crank to start, but it doesn't, does tipping the throttle help? Have you had scanning equipment connected during the hard-start/non-start? I've seen a couple of trucks with intermittently failing TPS sensors, reading 5-15% throttle angle when throttle is closed.
11-09-2009, 08:29 AM
#24
it's consistent, cold start only, after parked for the night or 8 hours at work, warm day or cold.
I haven't tried giving it gas with the peddle, I'll try!
I scanned but didin't see much, I need to do it again and have a more experienced tuner look at my scan (planned)
thank you , that gives me a couple of ideas. I do have a 90mm throttle body...hmm.
I haven't tried giving it gas with the peddle, I'll try!
I scanned but didin't see much, I need to do it again and have a more experienced tuner look at my scan (planned)
thank you , that gives me a couple of ideas. I do have a 90mm throttle body...hmm.
11-09-2009, 12:29 PM
#25
Sounds like your fuel pressure is bleeding off after engine off.Alot of trucks experience this as anti flow back valve sticks.Try turning on key for 2 seconds before engaging starter,giving fuel pump time to prime.Usually it will fire right up if this is your problem.You can test this with fuel pressure gauge hooked to shcrader valve on fuel rail.Turn of engine and see if fuel pressure bleeds off.The only real fix to this is a new fuel pump.
11-09-2009, 08:03 PM
#27
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it's consistent, cold start only, after parked for the night or 8 hours at work, warm day or cold.
I haven't tried giving it gas with the peddle, I'll try!
I scanned but didin't see much, I need to do it again and have a more experienced tuner look at my scan (planned)
thank you , that gives me a couple of ideas. I do have a 90mm throttle body...hmm.
I haven't tried giving it gas with the peddle, I'll try!
I scanned but didin't see much, I need to do it again and have a more experienced tuner look at my scan (planned)
thank you , that gives me a couple of ideas. I do have a 90mm throttle body...hmm.
So the supercharger knock is common? It just seems that the hard start is makeing the SC knock or vise versa the supercharger knock is making the hard start for the truck!
11-10-2009, 12:53 PM
#28
supenia4 - has the temperature dropped recently where you are? I think both the hard starts and knock ARE related. Sounds like the initial starting parameters are off in cold weather. It takes a couple of seconds for idle to adjust, which causes that stumble on initial start. That stumble (lope) is the cause for the rotor knock.
11-10-2009, 09:22 PM
#29
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supenia4 - has the temperature dropped recently where you are? I think both the hard starts and knock ARE related. Sounds like the initial starting parameters are off in cold weather. It takes a couple of seconds for idle to adjust, which causes that stumble on initial start. That stumble (lope) is the cause for the rotor knock.