Chevy Colorado intermittent starting problem

Here’s a stumper for you - I’d love any suggestions to take to the dealer! My 04 Chevy Colorado truck intermittently won’t start. It’s done this several times a year since I bought it new. It tends to happen in clusters; a couple of times in a row over a week, then no problems for a year. I’ve noticed now that it has always happened in cool weather, but I don’t know if that’s important. When this happens, it cranks but won’t turn over. The battery is fine. If I wait 20 min to several hours, it will finally start & seem perfectly normal. The one thing it won’t do, is repeat this for the mechanic at the dealership! I’ve had it towed over there twice, only to have it start up like a champ as soon as they turn the key. & you know, if it isn’t broken, they can’t find what’s wrong with it! Thanks - C

Can you hear the buzzing noise from the fuel pump when it is priming the fuel system when you turn the key to the ON position? If not you may have a bad pump.

The next time it won’t fire up when the starter is cranking the engine over, remove the air intake to the throttle body and while cranking, spray a shot of starting fluid into the throttle body.

If it fires up, you have a fuel supply fault.

My 2004 Colorado 4 cylinder has been plagued with similar issues. When the truck was in New Mexico for a number of years, it would only happen if I had not driven it for a while (months), and then drove a short trip. So my thought was moisture. I drove the truck back east, and it has happened more frequently. Like Carmen above, it happens in groups. So maybe a dozen times this summer. The common threads are:

  1. If you let it sit for 15 minutes, it starts normally - no blue smoke, no gas smell, no roughness, and no delay - Just like when the condition is not happening - Turn the key, one revolution, and it starts.
  2. It typically happens when you start normally, go for a 3 to 10 mile journey, shut it off, then try to restart after 10-15 minutes. If I go farther, then all is well. If I try to start it when the condition is happening, the thing just spins over without ever a sputter. If I wait 10 minutes, it just spins over without a sputter. If I wait 15 minutes - it starts on the first revolution - no smoke, no gas smell, no rough running.
  3. It seems to happen the same whether it is raining or dry and sun shining.
  4. the weather has turned a little cooler, so I have not seen it for a couple of weeks.
  5. I read somewhere that you should wait for 5 or 10 seconds with the key on before starting. I tried it a number of times - no effect.

My mechanic has searched his database of weird things, and nothing. My guess is that it is starved of gas since there is no smell or rough idle. I am also guessing that it is not just a pump issue, since when it starts - it is immediate. Maybe a temperature sensitive computer control on the injectors???

Has this been solved yet? I am having this exact problem. In clusters a couple times a year. Mike

It has not happened since the weather turned cooler. I drove it back to New Mexico from CT at Thanksgiving, pulling a trailer, and it ran flawlessly. I have to believe it is an electronic component that controls the fuel delivery, but I cannot get it to happen at the repair garage. Nothing is recorded in the computer. It has been wet, cold, warm here in NM, and it has not happened. You just have to pray that it doesn’t happen when you haven’t got 15 minutes to spare.

I’ve experienced the same thing 3 times with my 2004 Colorado. Twice it happened after a short drive and short stop. The third time, it happened first thing in the A.M. The first time, I paid for a tow and for the dealer to plug it in and tell me nothing was wrong. That was a few years back. It’s happened twice this week.

Cranks, won’t start. Notice that it turns slow and lights look different. Last time this happened, after several attempts I heard clicking a few seconds after turning the key to on. The lights got brighter and it would crank faster. Still wouldn’t start. A few tries later it started. I know my truck was wrecked and repaired. I was wondering if anyone else having this problem owns a repaired vehicle. Love my 07 Colorado but she’s making me look bad and hurting my earning potential.

It probably has to do with the passlock system. Google it, same problems… no answers really. Someone cleaned the connectors and he said it hasn’t had the issue since. Hope this helps.

This is an article on how to bypass it, including using an OEM unit.

This is a tough one. Well, I guess you have break it down. It needs gas in the right ratio and a spark with the right timing to start. Probably simplest to start with the spark. Does it have a good spark at the sparkplug when it does this? There’s gadgets available that you insert in-line in the spark plug leads, which makes determining this easy to do. Harbor Freight sells one.

I also have a 2004 Colorado and have the EXACT SAME SYMPTOMS as like2Ride above. I’m thinkin’ it’s a computer issue or a connections issue. Seems normal at the dealer and unless I’ve been doing lots of stop-and-go activity. Once it cools down (15 mintues to an hour)… cranks normal again.

By the way… just for clarity… starter spins great… when it’s acting out, engine behaves (if you’ll pardon a term from my old, old Studebaker days) as though someone has disconnected the coil.

Now to see if I can find more about the passlock or cleaning connectors.

I’ve got a SIMILAR problem with my 04 Colorado. It runs great for the most part but every once in awhile, 3-5 times a month, it wont start on the first turn of the key. The difference with mine is that the engine will NOT turn over. I hear a solenoid click, hear the gas pump, but the starter doesn’t turn. If I turn it off and on a few times (anywhere from 3 to 50) it does eventually turn over and usually start. Although twice it got flooded and I had to wait 20-30 minutes. I’ve had the starter replaced twice and the ignition switch replaced once. The starter is a big job to replace so it’s expensive to pay someone. I’ve got 160,000 on the truck and it is an everyday highway driver.
Any thoughts?

My truck: 2007 chevy Colorado LS 2.9 liter.
PROBLEM: would not start for me early in the morning when I tried to go to work. This would happen every few months. I would turn the key to start and it would crank but not start. I would wait 10 minutes and then it would start again fine like nothing happened. Got tired of this so I took it to a dealer since I believe the problem to be with the anti theft system known as Passlock.

Well got my truck back from the dealer today at the cost of around 360 dollars.
I’ll just type what it says on my receipt.
“Scanned Vehicle and found a history code set B2960 for security system. Checked SI and found DOC ID 2263073 advising to replace Ignition Switch housing for this concern. Replaced Switch housing and performed theft Relearn.”

Well I got the truck back. I hope it fixed it. time will tell. Not sure what all that says on the receipt but hope it works. Just tired of going out to the truck in 30 degree weather at 4:00am to go to work and having this happen. Again didn’t happen often but I need a reliable ride to work on time. if this does not fix it maybe it’s time to say good bye to my little Chevy Colorado. I hate to see it go… such a nice riding truck and good MPG for this size truck.

Thanks sincerely for the followup post. We learn through feedback, and a good ending is always a pleasure to hear anyway.

Sincere best.

The ignition switch housing contains the passlock sensor. When the sensor starts failing, you’re going to get no-starts.

Not entirely uncommon on GM vehicles.

Sounds like a reasonable charge for diagnosis and repair.

I guess if I had this problem, the first thing I’d do is check to see if I have spark (at at time when it isn’t starting). If a good spark was present, the next thing I’d do is check the fuel pressure at the rail. I expect one of those two tests would point you in the right direction for a fix.

How could I possibly check for spark or fuel pressure? It will not turn over when this occurs.

You might look at any of the chassis grounds. Give them a look and remove/clean if needed. I recently had something similar although the car would start but run horrid. It was intermittent and more common when cool and damp outside so I figured it was electrical. Someone suggested I clean my grounds on the problem is gone.

@peg-leg you don’t need the engine cranking over to have fuel pressure at the rail.

When you have the key in position 2, the fuel pump should energize.

You will not have spark if it’s not cranking over.

May 23, 2013
I have a Colorado 2006, and I too have had all the same problems with intermittent starting, will start and then stop and retart as if nothing happened 10 minutes after. Same as cartalk porkchop, I too went to the dealer to have them replace the ignition start switch with passlock sensor, $420.00, GM will not reimburse the repairs, I TRULLY BELEIVE THIS ISSUE SHOULD BE ON THEIR RECALL LIST, AS MANY MANY PEOPLE ARE HAVING THE EXACT SAME PROBLEM,
How could we go about trying to get this on their recall list , anyone know? will definately sign a petition if needed.
Thanks everyone