help GM tech please ...1999 chevy suburban

Clean the battery and connection terminals REAL GOOD. old john

It might be low voltage and not enough amps to start the engine.

Anything's possible when you throw in aftermarket electronics, especially if NOT installed correctly. Shit, I'm a DIY type of guy so if this were me I'd think about normalizing the electronics back to factory or take it to someone I -KNOW- knows what they're doing.... also may be familiar with whatever chipset we're talking about.

the terminals that go to the starter are different from the power circuits. In 3 cases, cleaning the other terminals GOOD with baking soda and water fixed the problem. a new battery does not mean the terminals are clean and low voltage goes to the power circuits it may turn over great, but the voltage to the corroded terminals is bad. old john. This may not be your problem , but it sure has happened to us.oj

Hello, Chevy! You wrote on Sat, 28 Jan 2006 19:49:10 GMT:

With best regards, snipped-for-privacy@comcast.net. E-mail: snipped-for-privacy@comcast.net

Chevy Not sure if this was done yet but you may want to have the sensors checked. Sounds like either the heated O2 sensors are not heating up fast enough. Or even the crank or cam sensor isn't catching just right. This becomes real important when there are aftermarket chips put in. Normally hey a tweaked so close to the edge of a sensors capabilities. That if they are off at all. It may not throw a code but it could create initial starting issues. Also look at the fuel pressure coming from the pump. Make sure it's constant at the recommended pressure. Final thought is that many of those "Performance" chips require you to run high octane fuel to keep from getting a bad detonation. You may want to try a jar of octane booster before you get into deep diagnostics. Many of these so called aftermarket upgrades I've tried on my 96. Even ones GM Performance plus said would work fine. I always end up going back to good old common sense and just putting in toys that boost up to just what the computer can handle. Seems unless you have money to burn on reprogramming AFTER you put in the "Super" chips. The performance gains never outweigh the cost!

Just some thoughts!

I've also got a '99 Suburban w/ a 350 (5.7L) with a similar issue. What I have found thus far:

1) I treated the initial problem as though it was a frozen gas line or just a whole bunch of water in the tank... It worked, but after the 3rd time of happening I started digging a littile deeper...

2) It only gets to the point that it won't start if I don't run it for a couple of days.

3) MOST of the plugs are wet (with gas) if I just keep cranking and cranking and cranking...

My fear is that I'm losing pressure in a few of my fuel injectors... but I think if I bring it to a garage, they'll let it sit for a few days and then tell me that I must have water in the tank... I know this to NOT be the case.

I've also found that I'm slowly losing my Dex-cool coolant. No coolant smell in the exhaust, no sign of it in the oil, sometime a FAINT smell of coolant under the hood... not sure if any of this is related.

When you take it in, tell them you drained the tank. This way they don't tell you that could be the cause.