Has anyone else had this/these problems...

BowtieZR5 · Post by **BowtieZR5** » Tue Feb 17, 2009 5:34 pm

When starting the truck up sometimes it doesn't want to fire immedently. if i try for about 3 seconds and stop it will fire imemedently.

On a rare occasion, while at driving speeds some times it will misfire or something. The first time it did this I thought I had hit a board or something else in the road. I though it may have been "vapor lock" due to the fact that it was 105 degrees outside. Then it started to do it at other random times. In the winter, summer, spring or fall. Outside temperature didn't seem to matter.

I have heard some imput from friends who are a little more knowledgable about vehicles than i am that the starting issue may be due to a bad fuel pump or filter. Help me please. These are the only major issues I have had with my ZR5. The other problems are minor in comparision... like the window will only roll down 3 inches. Thats no big deal, or at least I can work with/around it.

F9K9 · Post by **F9K9** » Tue Feb 17, 2009 9:31 pm

If, you have never changed the fuel filter then, I would start there before going any further. If, you have and are still having problems then I would turn the ignition switch to "on" and leave it there for 5-7 seconds before trying to crank it over. If, it cranks and starts up "smartly" then you need to start looking at fuel pressure. I'll leave that to the wiser heads in the forum on telling you what to perform next in the way of tests.
I do think that I speak for all when I suggest replacing the fuel filter first before going deeper. It's the cheapest possible cure and is just plain common sense to get that done before going deeper into the problem. HTH

BowtieZR5 · Post by **BowtieZR5** » Tue Feb 17, 2009 11:50 pm

ya ive had the fuel filter changed a couple of times. including since the problem started.

barch97 · Post by **barch97** » Wed Feb 18, 2009 4:44 am

Check your distributor cap, are all six points worn about the same? Still driving on oem wires, plugs, etc? How long time/miles since tune up?

gofast505 · Post by **gofast505** » Wed Feb 18, 2009 10:16 pm

This is the exact problem I started having for about two weeks, I thought it may be bad gas but It is still happening. I am at 150K and feel it probably is the pump. I have changed my plugs and filters.

F9K9 · Post by **F9K9** » Thu Feb 19, 2009 5:26 am

gofast505 wrote:This is the exact problem I started having for about two weeks, I thought it may be bad gas but It is still happening. I am at 150K and feel it probably is the pump. I have changed my plugs and filters.

barch97 wrote:Check your distributor cap, are all six points worn about the same? Still driving on oem wires, plugs, etc? How long time/miles since tune up?

You guys keep missing the point here. It is all here and can be found through searching or ready the stickies. We all need to keep an eye on our Distributor , Distributor , Distributor . Distributor , Distributor , Distributor . Distributor , Distributor ,Distributor , Distributor , Distributor . Distributor , Distributor , Distributor . Distributor , Distributor ,Distributor , Distributor , Distributor . Distributor , Distributor , Distributor . Distributor , Distributor ,Distributor , Distributor , Distributor . Distributor , Distributor , Distributor . Distributor , Distributor , Distributor , Distributor , Distributor . Distributor , Distributor , Distributor . Distributor , Distributor , Distributor , Distributor , Distributor . Distributor , Distributor , Distributor . Distributor , Distributor , Distributor , Distributor , Distributor . Distributor , Distributor , Distributor . Distributor , Distributor, the Distributor Cap and Rotor!!!

The poor photos depicted below were taken when I had under 20K on my Crew. Less than 6 months later after replacing the cap and rotor, it looked the same way! Don't read the stickies and replace the cap and rotor and you will be paying several hundred dollars for a new distributor!

BowtieZR5 · Post by **BowtieZR5** » Thu Feb 19, 2009 2:12 pm

ok so i changed the fuel filter today. but yester i had a different problelm. while driving up hill the dang thing didn't want to go. i got it up to about 55 and started slowing down even though i was hard on the gas. the CES light was flashing. i took it to the local shop who hooked it up to the diagnostic reader and he told me i needed a new thermostat and had a vacume leak. but he would have to run a smoke test to find out where the leak was. after that, it would cost somewhere between $100 and $1000 to fix depending on where the leak was. so after adding 30x9.5 BFGs, the fuel filter, replaced the dead battery, oil change, fuel system cleaning ive dumped nearly a grand in THIS WEEK. Im really hoping the leak is something minor, like a hose or something. then i will go after sparkplugs and cap and distrubitor. but i cant seem to get the wife to understand that dumping $2000 into the truck is better than dropping $40G on a new Silverado Crew Cab.

barch97 · Post by **barch97** » Thu Feb 19, 2009 2:47 pm

LMAO, F9K9... So, you think it's the precat then, huh?

Cap, rotor, wires & plugs shouldn't cost much more than $100 or so and take less than an hour to install. If they're not the problem (but they probably are) you needed them anyway.

You probably oughta get that vacuum leak checked out before you sink too much more into optional upgrades. It could be very costly in the long run.

F9K9 · Post by **F9K9** » Thu Feb 19, 2009 5:05 pm

BowtieZR5 wrote:.............the CES light was flashing. i took it to the local shop who hooked it up to the diagnostic reader and he told me i needed a new thermostat and had a vacume leak.............................................

A flashing CES/SES/MIL is a catastrophic failure. Don't move it, rent a scan tool or buy one! A vacuum leak or bad thermostat won't create a flashing CES.

Get the codes from the scan tool and post them up here. Find another shop and do not darken their doorway again!

roadrunner · Post by **roadrunner** » Thu Feb 19, 2009 5:35 pm

Anybody thought to clean the MAFS? Flashing engine light is not always a catastrophic failure. I had one that ended up being a shorted O2 sensor wire which caused a lean/rich problem and led to multiple misfire which will causes a flashing CES light if it continues long enough. My .02 worth.

F9K9 · Post by **F9K9** » Thu Feb 19, 2009 5:47 pm

roadrunner wrote:Anybody thought to clean the MAFS? Flashing engine light is not always a catastrophic failure. I had one that ended up being a shorted O2 sensor wire which caused a lean/rich problem and led to multiple misfire which will causes a flashing CES light if it continues long enough. My .02 worth.

catastrophic failure is the technical term associated with a flashing CES light. I am not going to tell him to go and drive it. I have had one for a misfire in my POS heep and limped into an auto parts store. My scanner was home in my CC. I wasn't going to take the chance to drive it home. I "rented" it, got the codes out of it, got my money back, and replaced the plugs.
A flashing CES/SES/MIL is serious stuff. We don't need to let members drive with it flashing when the problem is not known. Let them make the call.

A thermostat or vacuum leak is not going to create the flashing MIL for those two symptoms.

roadrunner · Post by **roadrunner** » Thu Feb 19, 2009 6:26 pm

Simmer down Reed! I was merely pointing out that there are other things that cause a flashing CES light. Perhaps I am a little more fearless because of extensive mechanic background. Yes, you are correct the term catastrophic failure is in the book for a flashing light. Be aware though it is a general term intended to make sure people get proper service not that the vehicle isn't driveable. Sometimes the flashing light indicates that emissions are way out of spec due to a recurring problem. Not good but definitely driveable. Years ago many makers simply stated that the light would put the vehicle in "limp" mode. Meaning it would run with reduced efficiency and power but could be "limped" in for service. Later on they decided people were ignoring the light too much and decided to make it a two stage thing. Simpler less important causes would simply turn it on. More major fuel/emission/recurring problems would make it flash. This was done primarily to make sure the light wasn't simply ignored by the driver. My intention was not to say he should ignore the flashing light but to indicate that there are less than "catastrophic" problems that could cause it simply by their ongoing duration and frequency.

Post by **HenryJ** » Thu Feb 19, 2009 6:35 pm

Do not think of the MIL as a gloom and doom for the engine light. It is a polluting the atmosphere light.
That is the way I like to think of it.

roadrunner · Post by **roadrunner** » Thu Feb 19, 2009 6:37 pm

Simply stated and well put Brule!

F9K9 · Post by **F9K9** » Thu Feb 19, 2009 7:26 pm

OK, let's try to put this into "a Level" of concernA flashing MIL is of greater concern that a "steady" CES lamp

Post by **HenryJ** » Thu Feb 19, 2009 9:29 pm

True. The flashing light means the condition exists and is occurring. Continued performance in this condition can lead to emissions system component damage.
A steady light means that a code has been stored.

smallblocker · Post by **smallblocker** » Fri Feb 20, 2009 1:27 pm

Can be a "cost money Light" too. Continued multiple missfires can load the catylitic converters with gas and burn them out costing big bucks.