After a few days of starting flawlessly, my 2001 4-dr 4wd vortec gave me a hard time starting again yesterday. No codes. (SES light comes on during starting issues, but doesn't stay on. Low fuel light may have lit temporarily at one point?)

It almost started, didn't quite make it, sputtered out. I cranked the ignition, stepped on the pedal (does that even matter in an electronic FI engine?) and finally got it going, but it ran rough, maybe to the point of stall. Misfiring I'd guess, but it doesn't misfire like the last V6 I had misfires on where I had a bad tube seal ... it's a lot quieter but also rougher and feels more likely to stall.

After revving it and running it a minute to see if it would smooth out, which it did not, I killed it. Restarted it without difficulty, ran as smooth as it typically has since I've had it (not 100% super smooth, but nothing I'd take notice of usually either). Took it out to run some errands, had it running for an hour. Felt a little rougher when I got it home, but could have been my imagination.

Battery's about new. Filter's not that old. MAF got cleaned when I did filter. Wires are tight, but haven't checked plugs. The plugs/wires haven't been done since I picked it up used ~15 months or so ago, so they're probably pretty old. Does this sound more like plugs & wires, injectors, or what?

Thanks for any help!

 

History--> ack! codes, codes, codes! & Suddenly won't start

Most of the time it is best to keep things in one thread so we can see what has been suggested and tried... Cuts down on repeats.

Fuel pressure test results??

 

First thing you need to do is get the codes checked and let us know what they are.
Then clean the throttle body, EGR valve and IAC to knock out some other common issues with rough starting due to airflow.

Pull the plugs and see how they look. You can tell a lot about what is going on in your engine by how the plugs look. Take a picture and post it if you are unsure how to help diagnose an engine by looking at the plugs. If they look bad then replace them along with the wires, cap and rotor.

You will also need to check for vac leaks and run the fuel pressure tests that swartlkk suggested.

 

Hi all,

Sorry it's been a while, I've been slammed with work, trying to wrap up my consulting commitments, having started a new fulltime job.

Truck's at the dealership. Apparently the secondary AIR pump needs replacement -- $8xx they're telling me in parts. The EVAP codes are apparently related to fuel pump sensor and solenoid. I'm awaiting a detailed fax with breakdown of costs, but right now, dealership wants $2900ish to fix it. I'll get a comparison from my neighborhood garage too of course ...

Will update with more details, thanks for all the info all along the way here gents ...

 

You mean the fuel tank pressure sensor and canister purge solenoid I'm guessing.

Purge solenoid is about $40 and you can replace it yourself in about 5 min or less.
The tank pressure sensor is about the same cost and can often be replaced without needing to drop the fuel tank if you remove the spare tire first so you can see what your doing. At worst you will need to drop the tank a few inches if you have big hands and can't get in there.
I did it on my 01 blazer this way without problems. Took maybe 10-15 min tops.

The AIR pump costs roughly $220 according to rockauto.com but if I were you I would be certain that is actually the problem first. There is a check valve on the pump that can be replaced separately that is known to go bad. I've never had to put one of these pumps in but it doesn't look to hard from the diagrams I've seen of it.

Obviously that's less then $800 in parts unless they are hand manufacturing each of them themselves.

$2900 to fix that assuming that they are actually replacing parts that need to be replaced is definitely way to much. They do have the nickname stealerships for a reason.

What were the codes that came up anyways?

 

The codes are all the same from the link Kyle posted above:

p0410
p0418
p0440
(p0441 too maybe?)
p0442
p0452
p1154

I think that covers it ...

My trusty neighborhood garage is thinking $800 in parts and 6 hours in labor. Taking it in in 2 hours. F*ck dealerships. I know they're Satan, but I haven't had one try to ream me like this in YEEEEEARS. Then again, I haven't gone in for serious work at a dealership in years either ... I was doing my own work when I still had a garage.

 

P0418 Secondary Air Injection System Relay ‘A" Circuit Malfunction.

If I were you I would make certain that they replace the bad relay FIRST. Then clear the codes and retest before you get taken for a ton of cash that may not need to be spent. If the relay has a problem it can cause the failure codes for the rest of the AIR system.

A new relay is $15. Check it first since you actually have a code telling you that the relay has a problem.

The p0440 code is just a generic evap problem code and can be caused by something as simple as a bad gas cap as happened on my 01 blazer.

The p0442 code indicates a leak in the system. Which again could be a bad gas cap or a hose with a leak in it.

P0452 is a low voltage signal from the tank pressure sensor. This can indicate either a faulty sensor or a leak in the system causing low pressure in the system. Considering the codes it could be low pressure from whatever leak is causing the 442 code. Yes even a bad gas cap in theory.

The last one p1154 is an O2 sensor code. Which is common to get when you have evap problems as the engine tends to swing from lean to rich.

Don't let them just replace everything playing shotgun mechanics. Make them actually find the cause of the problem and fix one at a time and retest since you have many codes that can set off others but could all be from a single simple cause.