decepts

Hello,

First off thank you for taking the time in reading about my issue for it is much appreciated. I have had this issue for going on 3 years now and can't get / find a solution and have had many look at this issue including a Chevy dealership with no luck.

Vehicle: Chevy W4500 Tiltmaster
Motor: Vortec 5700 L31 v8 5.7L
Trany: 4L80-E
Symptoms: From a stop to start (light to full gas) at times (happening more often) vehicle tends to hesitate / bog then feels like it shifts (happens in reverse and drive). Sometimes (happening more often) when put in reverse or drive you may hear and feel the idle surge (RPM's go up and down) had vehicle die several times because of this. I have also noticed that (very rare but happened a couple of times) in stop and go traffic that the vehicle felt like it was kind of jumping when I was moving very slowly and coming to a stop. Basically vehicle feels like it is bogging while slowly moving (doesn't matter how much or little you put your put down) then shifts and this shift can at times take up to 4 seconds.

Tried / Done: I have done a lot to try and solve this issue. I have given the vehicle a complete tune-up (plugs, wires, coil, etc), ran several bottles of fuel injector cleaner and much more. When the tranny went I had it rebuilt and ever since then when I got it I noticed a VERY slight "hesitation" and things have slowly grown where it is now. Part of me thinks that I might have a torque converter issue but I paid to have it replaced again thinking that it may be the case according to a bulletin a tech had mentioned.

I am VERY frustrated with this issue for it has been around for about 3 years now and is only getting worse over time but not bad enough to throw any codes or to even fail. There are no fuel pressure issues or vacuum issues found. This is my work vehicle (landscape maint. truck that tows a trailer 99% of the time) and really would like things working properly. Any help would be GREATLY appreciated and I am willing to try anything to try and solve this issue..

Thanks!
<O</O

maxxman04

check fuel pressure, could be bad fuel pump. also, clean egr and idle air control valve. have the cam offset (basically timing) checked. a good shop will know what this is and how to check/adjust this.

decepts

Done that... Fuel pressure is proper and has good strong pressure even under hesitation. Fuel pump was replaced due to the fuel level pickup not functioning properly. EGR was replaced for I thought that was possibly the issue. IAC was replaced for I broke the old one when inspecting it out of the vehicle. Checked timing on vehicle with a timing light and it appears to be fine and in check with the computer. Timing is also not adjustable on this vehicle. I also replaced the cam position sensor...

Does anyone think that possibly the TCC Solenoid may be going bad? This is something that I've been thinking but not sure.

maxxman04

true timing is not adjustable. it's the cam/crank offset beibg measured, which should be within 2 degrees either way of 0 degrees tdc. a timing light cannot read this. only certain diagnostic equipment can.
was tps replaced?

decepts

How can I measure this cam/crank offset of TDC? Nothing comes to mind right off hand.

The TPS had not been replaced but I did test this by looking at the live data being read from my OBD II reader and slowly pushing in the throttle and slowly lifting and I didn't see anything wrong from what I saw 0% up to 100% and back down with no dips or lack of a reading.

maxxman04

again, unless your scan tool reads the cam offset specific, a shop has to read it. a scan tool should read cam offset, or cam retard, something like that. if you do not see this listed in your live data, then you cannot read or adjust it properly.

decepts

I will check this out tomorrow morning for I think I remember seeing a cam offset reading on my scan tool.

What are your thoughts about the TCC solenoid? Only reason why I kind of think it is a possible tranny issue is because these issues only started soon thereafter the tranny was rebuilt and before then the vehicle was operating perfectly.

Thank you for your input for it is greatly appreciated.

decepts

Another note: When driving and from a stop when I get on the gas it feels like I might be starting out in possibly 2nd gear. Same symptoms are in reverse but it's not like a got a second gear in reverse. Whats weird it the vechile moves but lugs and then all of a sudden it feals like it shifts or "clears out". So yeah it might be a timming issue but I'll check the cam offset tomorrow to just verfiy this.