SOLVED! Crank no start when rains

[Ilikemy3s]

Hello group. Having a weird crank no start issue with my 05 SWB TB LT. Daily driver Some history below. ...
* Bought it in 2015 with 85K on the odometer. Now at 238K.
*Always used mobile 1 oil and filter.
* Would probably be at 300K miles if not for pandemic lock down
* Did maintainence when needed if not before.
* Fluids changed on recommendations if not before
* 100K and 200K tuned ups with plugs and coil packs
* Replaced Thorttle body assembly about 3k miles ago
* New fuel pump assembly installed about 6 weeks ago.
No issues starting until now. Rained the past few days off and on. Not heavy but consistant and steady. Went to start the other day and it did not start on first two cranks, it sounded like it wanted to start, but only did on third try. Idled a bit rough at first but then calmed down. I let it idle for a few minutes. Check engine light on yet ran fine rest of day. Pulled codes when i got home and there was P2135 : P2101 : P1516. Cleared codes and ran fine rest of day. That was Friday. Still more rain. Went to run it early evening yesterday (Sat) and same thing, this time it would not start at all even after 5 attempts. Can hear the fuel pump priming when key is turned. Any thoughts on what it could be or what to look for ?

 

[mrrsm]

Here are some ideas to consider... Starting with:

(1) The Throttle Body

With the codes relating to "Reduced Power" or intermittent stalling, sometimes, the Throttle Plate (Butterfly) can actually get wedged in the opening of the Venturi and jam solid...even on an ostensibly Brand New Throttle Body.

THIS Brief Video is illustrative of successful Diagnosis and R&R to put things right. Trying out a Used Throttle Body vs. Buying a Brand New OEM version from Amazon will save some money if it solves this problem:

Another Oddball Diagnostic Method is to Remove the Throttle Body and "Give it the SHAKE TEST...". If you can hear ANYTHING rattling around under the Electric Motor and Gearing Housing... THAT will indicate replacing the Throttle Body should follow on.

For the sake of SAFETY ... In order to prevent ANY conditions where the actual position of the Throttle Body Butterfly Plate becomes indeterminate, the PCM will automatically default to a Reduced Power Condition. The Usual Suspects can be either a FUBAR'd Throttle Body... a FUBAR'd ACC Pedal...a FUBAR'd MAF (if present) or any combination of the three including Shorts in the Wiring Harnessing.

As for the issue with "The Rain" being involved, if Rainwater invades under the Hood Cowl Seal and pours down over and then inside of the Valve Cover inside the Spark Plug Wells, The COPs and Plugs can short out. This Thread addresses this issue:

Need to know what the new hood seal looks like.

I suffered the Cyl 4 misfire problem, but it hasn't reoccurred. It happened several weeks after I changed the plugs, so I may have disturbed the coil pack seal, 'cause it hasn't been a problem for 4 years of heavy rains & such. I think it was a matter of tree debris (acorns, twigs & leaves)...

gmtnation.com

And finally... the intermittent nature of the Starts & Stalls & No Starts issue can occur if the Wiring Harness(es) and Plastic Weather-Pack Connectors have been Chewed on by Rodents:



The Deer Mouse in particular will take up residence under the hood and pull down the hood liner, creating nesting materials with its Fur and Twigs & Grass.

THIS material will have friable Rodent Urine and Feces within that can carry the dreaded HANTA Virus... so Mask & Glove Up if you investigate the entire Engine Bay with a Bright Flashlight and find any traces of their invading presence to avoid breathing in or touching this Dangerous Dust.

 

[Mooseman]

I'd have to agree that it would be the throttle body rather than the pedal. If it was just the P2135, it could be either however the other two codes point more towards a failing throttle body. As suggested by @MRRSM , I'd try a used throttle body first. If getting it from a U-pull yard, might as well grab the pedal too just in case.

I'm thinking the rain is either just coincidental or may be affecting the internal sensors of the throttle body.

 

[budwich]

OP, you indicated that you replaced the tb 3k ago... was that with a new or used one? any reason for the replacement effort?

further, you indicated that you cleared the codes ... are there any codes currently in the present no start?

 

[Ilikemy3s]

OP, you indicated that you replaced the tb 3k ago... was that with a new or used one? any reason for the replacement effort?

further, you indicated that you cleared the codes ... are there any codes currently in the present no start?

After I got the truck started and running today and took it for a test ride, after a few miles, the truck went back into RPM (Reduced Power mode) and i pulled over to side of road where it stalled and would not start. Called for a tow. Did not clear codes. While waiting for tow truck it did start again, but I was not going to chance it and had it towed to the shop that last worked on it. The TB was replaced due to same issues about 3 K ago going back to early Oct. but has ran great since. At that time I did try cleaning the TB that was on the truck, same issue. I then replaced the TB. same issue. had a shop look at it with better diag equipment than I had, they determined the discount TB i bought was defective. They replaced it with a Napa brnad and it work great .. until now that is

 

[mrrsm]

There are Two other possible problem areas that can still be inexpensively investigated:


(1) Once you have the Vehicle Started and Idling in your Drive Way... Raise the Hood and *jiggle* the Throttle Body Harness and other adjacent Harnesses ...just to see if that action causes an Intermittent *Short* to reveal itself.

(2) Replace the GM 4.2L Throttle Body Connector & Pigtails Leads via an OEM Quality Delphi Unit available from ACDelco or eBay via this Link:

GM 8 pin Throttle Body Connector Vortec 2004-2007 4.8 5.3 6.0 | eBay

Any drive by wire GM with an 8 wire connector. Many 2002 to 2007 GM trucks and cars. Genuine Delphi connector. We reserve the right to substitute carriers. We are TSC Specialties LLC.

www.ebay.com

(3) If you decide to R&R the TB Connector & Pigtail Harness... Best Practices are to CUT-REPLACE-&-SOLDER ONLY ONE WIRE AT A TIME and use a Weather-Sealant Type of Heat Shrink Wrapping at each of the Hybrid Wire Junctions.

 

[Mooseman]

If you're getting the same issues, I'd take it back to the shop under warranty. Could be the tb again. Who knows where Napa gets them to put in their boxes. I'd trust a used one before an aftermarket one.

 

[budwich]

it appears that they did nothing... :-( next place to look is the voltages / signals at the connector of the tb. Of course, the likely cause of most of these type of problem is an issue with the 5v WHICH is usually somewhat related to an issue with the wiring for the electrical fan clutch area. This can usually be confirmed by electrical checks as suggested.

what are the current codes?

 

[cornchip]

Here are some ideas to consider... Starting with:

(1) The Throttle Body

With the codes relating to "Reduced Power" or intermittent stalling, sometimes, the Throttle Plate (Butterfly) can actually get wedged in the opening of the Venturi and jam solid...even on an ostensibly Brand New Throttle Body.

THIS Brief Video is illustrative of successful Diagnosis and R&R to put things right. Trying out a Used Throttle Body vs. Buying a Brand New OEM version from Amazon will save some money if it solves this problem:

Another Oddball Diagnostic Method is to Remove the Throttle Body and "Give it the SHAKE TEST...". If you can hear ANYTHING rattling around under the Electric Motor and Gearing Housing... THAT will indicate replacing the Throttle Body should follow on.

For the sake of SAFETY ... In order to prevent ANY conditions where the actual position of the Throttle Body Butterfly Plate becomes indeterminate, the PCM will automatically default to a Reduced Power Condition. The Usual Suspects can be either a FUBAR'd Throttle Body... a FUBAR'd ACC Pedal...a FUBAR'd MAF (if present) or any combination of the three including Shorts in the Wiring Harnessing.

As for the issue with "The Rain" being involved, if Rainwater invades under the Hood Cowl Seal and pours down over and then inside of the Valve Cover inside the Spark Plug Wells, The COPs and Plugs can short out. This Thread addresses this issue:

Need to know what the new hood seal looks like.

I suffered the Cyl 4 misfire problem, but it hasn't reoccurred. It happened several weeks after I changed the plugs, so I may have disturbed the coil pack seal, 'cause it hasn't been a problem for 4 years of heavy rains & such. I think it was a matter of tree debris (acorns, twigs & leaves)...

gmtnation.com

And finally... the intermittent nature of the Starts & Stalls & No Starts issue can occur if the Wiring Harness(es) and Plastic Weather-Pack Connectors have been Chewed on by Rodents:

View attachment 102611View attachment 102612View attachment 102613

The Deer Mouse in particular will take up residence under the hood and pull down the hood liner, creating nesting materials with its Fur and Twigs & Grass.

THIS material will have friable Rodent Urine and Feces within that can carry the dreaded HANTA Virus... so Mask & Glove Up if you investigate the entire Engine Bay with a Bright Flashlight and find any traces of their invading presence to avoid breathing in or touching this Dangerous Dust.

Interesting timing with your rodent damage information. Over the Christmas break I had a chance to fix the chaos a mouse did to my 25hp Evinrude Etec. It chewed the main harness, fuel injector plug and filled the inside with feces, dirt and leaves. I had to buy a used harness from a boat engine recycler in Dunnellon Florida. New cost $675 and used was $80. Keep them out if you can.

 

[mrrsm]

All Rodents have a distinct dislike and will avoid being around *** Peppermint Oils and their Vapors. So you can try soaking Cotton Balls with the Stuff and populate the various places you found the invasive Rodents and their Nesting areas. Victor makes a Peppermint Oil Device that does the same thing. Trust me... It WORKS...

I'm very sorry this has occurred... but glad to pass along my profound concerns about the Dangers of getting HANTA Hemorrhagic Fever.

During uncustomary heavy rains in the southwest many decades ago, the increase in the Rodent Population drove them into Desert Adobe Homes and Buildings, creating infected Rafter-Barn Dust that once inhaled, Doomed most of the less than 100 people it infected.

The virus is similar in behavior to the "Marburg" and "Ebola" Variants and there is No Vaccine for it. This Disease is normally spread via direct contact with Blood, Desiccated Urine and the Feces of the Common Deer Mouse and other Rodent Species and not through aerosolized coughing, sneezing or Fomites like those of the Colds, Flu and of course, all variants of Covid-19 inhaled or left on infected surfaces.

Thanks for sharing your experience with this matter...

*** Avoid using Naphthalene ..AKA ."Moth Balls", as these produce a HIGH LEVEL of VOCs that are Carcinogenic. The Mothballs vaporize over time and can fill the local area with excessive fumes. Naptha is dangerous to human health. During the Viet Nam War, NAPALM (Jellied Gas) was made by mixing Naphthalene with Pump Gas.

 

[Mooseman]

I just remembered that this could also be caused by a defective fan clutch. Unplug it and see if your problems go away (you will get a code for that though). In cool weather, there shouldn't be any overheating but keep an eye on temps.

 

[Ilikemy3s]

Truck is at the shop so I am waiting to hear back what they find.

 

[Ilikemy3s]

Solved : Minor vibration I have had with engine when cold for a few months, caused a wire loom retaining clip to fail and caused a wire to rub against the alternator bracket until the insulation was gone and the wire was shorting out intermintantly. Worn wire insulation has been repaired, section of wireloom replaced and resecured.

At least that is that is what I was told. Picked up truck last night ran some errands. No issues. But with snow fall last night an cold biting winds, I will check it later. But for now .. she is back on the road