2005 CR with no throttle response

CSnyder

CSnyder

Snyder-Motorsports
Joined
Mar 3, 2008
Messages
6,278
I just finished an engine rebuild and this throttle issue has me stumped. It is throwing a code for low input on the throttle with an engine light. Acts like a APPS issue on an older 2nd gen. However if you floor it the truck eventually gains to exactly 1200 RPM every time after roughly 5 seconds. It was all working fine for an initial hour long break in and about 5 miles of driving and when it started acting up it slowly got worse to the way it is now. I put a known good APPS in the truck (pedal mounted type) and no change. I then tried a new one I carry in stock and no change. I unplugged both the crank and cam sensors and replugged them, checked rail pressure at 6500 avg while idling. My MAC scanner says there are 2 throttle inputs. The first one stays at 0 and number 2 shows .2 at idle and will go up over 1.X when you floor it. I unplugged the FCA while idling and it starts rattling and goes away when plugged back in. I sent the injectors off for testing while torn down and 2 were bad and rebuilt. Is it possible the injectors are the culprit? truck starts right up and idles smooth. One of the guys who work here thinks the guy has a Smarty downloaded into the ECM which wouldnt surprise me the way it smoked after the break in with a snap on the throttle.

Any ideas?
 
I havent tore into it too deep yet since its outside but plan to bring it in after a trans install is finished and OHM the injectors next.
 
I would call the owner and ask about the smarty. I've had one do something Simalar. But not that severe. A redownload of my smarty helped it.

Mine was on my 03 with my SSR and after I let my Batts drain over a two week period I jumped it off and it ideled fine and I made it to the drive way end. And then had no pedal. (About .5 miles) and I redownload my smarty after returning to shop and installing a new battery. Has been working fine since. That may or may not be your case tho.
 
Gibson said:
I would call the owner and ask about the smarty. I've had one do something Simalar. But not that severe. A redownload of my smarty helped it.

Mine was on my 03 with my SSR and after I let my Batts drain over a two week period I jumped it off and it ideled fine and I made it to the drive way end. And then had no pedal. (About .5 miles) and I redownload my smarty after returning to shop and installing a new battery. Has been working fine since. That may or may not be your case tho.
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From what I understand the guy doesnt have the Smarty. It was in the truck but the guy didnt give him the controller. Engine was removed only 2 weeks ago and it fired right up after getting it together. I will test batteries first thing this morning.
 
I don't see injectors being the culprit in this. I would expect it to haze, run rough etc. Don't see all 6 of them malfunctioning in this type of manner.
 
You might test the voltage at the APPS. The 05 does have two circuits, the voltage on one is half of the other one. This is done to validate the input from the APPS. If one is not half of the other, it doesn't get much above an idle. What code does it set?

Paul
 
P2122 and P2127 should be either a APPS sensor or wiring problem. If you changed the APPS sensor check the harness for a broken or bare wire.
 
f6jbob said:
Chris, I'm pretty sure a 2507 code is an intermittent 12volt problem. I know you said 2607, just wondering if that's right.
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No its a 2607. its for the air filter sensor according to the MAC scanner. Thanks though!
 
Did you mess with any of the wiring to the APPS? Almost sounds like the wires are swapped between the two circuits on the APPS.

Tobin
 
P2122 and P2127 should be either a APPS sensor or wiring problem. If you changed the APPS sensor check the harness for a broken or bare wire.
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I am going to assume they don't share a common ground (could be wrong never dealt with this in particular before), I would start look for problems there after you check the harness itself.
 
Tobin said:
Did you mess with any of the wiring to the APPS? Almost sounds like the wires are swapped between the two circuits on the APPS.

Tobin
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the APPS has one plug in on the pedal under the dash. It wasnt touched for the engine rebuild until I tried swapping in a new APPS to try that.
 
Check for a connection issue in the large connector between the engine and the chassis. Pin/s backed out etc. 90+% of the time it's something you had apart recently. Also be sure the engine to chassis/body ground strap is ok.
 
LReiff said:
Check for a connection issue in the large connector between the engine and the chassis. Pin/s backed out etc. 90+% of the time it's something you had apart recently. Also be sure the engine to chassis/body ground strap is ok.
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well I had checked it twice already but went back and put dialectric grease on that main plug and f'n A wouldnt ya know it the SOB is back to normal...

These new electronic plugs these newer trucks have are a damn joke.

Thanks everyone for the suggestions and hopefully someone with a similar situation will stumble upon this and find his answer.
 
Glad you figured it out. Those 2 plugs on the firewall that have the swivel lock always seem to break and keep it from fully seating.
 
diesel_importer said:
Glad you figured it out. Those 2 plugs on the firewall that have the swivel lock always seem to break and keep it from fully seating.
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On my own truck years ago I broke my own when I pulled the engine and had so many issues with it myself that Ive always been extremely careful taking them off since and havent broken the swivels on a single truck. Someone has had this one apart and broke it before, but it was locking in yet. After I discovered the issue yesterday I ran a few zip ties around it to hold it together after the dielectric grease fix.
 
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