TCL_2000_ChevyXprs3500

First, let me start out by saying I am new to this discussion forum and this is my very first post. I have searched the forum and found "similar" issues to what I have but none the fit exactly, so hence my post. Any advice and tips you can offer are greatly appreciated.

My van is a 2000 Chevy Express 3500 (5.7) with apx. 140,000 miles. I've had it only for 8 months and it has never given me a problem until recently. The first problem was an occasional dead battery. Never could find a reason until last weekend when I happened to walk by the vehicle and hear my blower motor running. Researched online and read about the resistor being the likely culprit. Charged the batter since it was almost dead and purchased the resistor and installed it. Fan no longer blew with ignition off.

However, the van no longer starts. Checked all fuses (in car and under hood) and all looked good. Replaced the fuel pump relay. Still no start.

Hooked up my scan tool to the obd2 connector, it will not connect to ECM! Double checked fuses (including the cigarette lighter which powers the obd2 connector) and again, everything looks good. With a test light I see power on pin 16, which confirms that the fuse I checked was good.

I do NOT hear the fuel pump coming on for the 2 seconds that it's supposed to right before the car starts. So the fuel pump might be bad, but how can I rule out the ECM. If the ECM is bad, it won't send a signal to fuel pump. If I unplug the fuel pump relay, can two of the pins be jumped to send juice to the fuel pump to test it? If not, what's the easiest way to test the fuel pump? I don't have an assistant so I can't rely on a second set of ears or hands!

Spoke briefly with service center at local Chevy dealer. They gave me one tip, and that was to remove and clean the connectors to the ECM. They are a pain to get to and I'd hate to damage he wires trying to get them off -- especially if this isn't a likely solution. Is this worth doing?

Can anyone think of any other tips?

I guess I'm hoping it's the ECM since that is far less expensive to replace than the fuel pump. I have to work on this vehicle in my driveway (which is gravel) and I'm not sure I can even jack it up to work underneath and drop the tank. This is a HEAVY vehicle -- actually this is a RoadTrek RV built on a Chevy Express 3500.

Again, thanks in advance for any help you can provide! :-)

TCL_2000_ChevyXprs3500

Forgot to detail no start condition. Van cranks, sounds like it starts, then immediately dies (1 second or so). Definitely sounds like it wants to start so that makes me think I'm getting gas and spark, at least initially.

spaceblonde

I would say first thing is to give it a little spray from starting fluid ,, if it fires then fuel is your problem.

if not then it's a spark issue .

Be willing to expect fuel pump common issue for GM's .

TCL_2000_ChevyXprs3500

Thanks for the tip SpaceBlonde. The van 'tries' to run, and in fact sounds like it's running for 1 second as I mentioned before cutting off. That confirms I'm getting spark, which does point suspicion towards the fuel pump. However, the fuel pump is controlled by the ECM, so if that's not operating correctly the pump won't kick in. The fact that my scan tool can't connect to the ecm (and yes, I checked to make sure the connector has power -- it does) makes me suspect it as the culprit. I've been told that the placement of the ecm in this van is less than optimal because it's right next to where water drips down into the engine compartment. I did notice that the drip tray was not on correctly and there is signs of corrosion on top of the ecm. Same person who told me about the location issue of the ecm said the connectors are also prone to corrosion for this reason. I plan to check that out after work tonight.

canucklehead

If the fuel pump is not runnng properly, you might get this issue. Do you hear it run a few second to prime the system when you turn the key to on? If you do then its primed and will have enough pressure to start, but if the pumps stops right away then the engine will sputter and die.
The fuel pump and starter relays are the same. Swap them. If you don't crank...its the relay. If you do crank...its the fuel pump.
Have someone crank the engine while you hit the underside of the fuel tank with a big rubber mallet or something......you just might jar the pump free and it will start. Then....go get it replaced. At least it will save you a tow.

TCL_2000_ChevyXprs3500

Thanks for the response canucklehead.

I don't have anyone that turn the key for me while I'm under the hood or under the car, but from inside I do NOT hear the fuel pump doing it's 2 second prime that it's supposed to. So on one hand that could be a sign the fuel pump is bad, or on the other side it could mean the ecm is not sending the signal to the relay to send 12 volts to the pump. Not sure if it's even possible to squeeze under this thing to check if I'm getting 12 volts unless I jack it up and I don't trust any jacks I have. This thing is HEAVY. It's actually a RoadTrek RV built on a Chevy Express 3500 chasis, so it's a lot heavier than a stock van.

I'll try the rubber mallet idea if I can squeeze under there and cross my fingers that it starts after a few whacks. I just found out that my road-side assistance does not cover medium-heavy duty trucks, so yeah, I'd like to be able to save the tow since that will be out of pocket.

spaceblonde

you might want to look into AAA they have coverage that covers RV's I have AAA Texas the RV plus gives me 1 200 mile tow and 3 100 mile tow's living in Rural Texas this was a no brainier for me. and only around $ 100 a year is cheap insurance.

TCL_2000_ChevyXprs3500

I'll have to look into AAA SpaceBlonde! Yes, $100 is a good deal. I decided to go ahead and have the RV towed to my local mechanic. He's only 1.5 miles from my house, tow was $85!!!

While I was at the mechanics I asked them to hook up their scan tool to see if they could connect to my ecm (they told they've NEVER seen an ecm go bad on these vans). Sure enough, they could not get a connection either! It may still be just a bad wire going to the ecm, hopefully they'll find out soon and I'll post the fix when I find out so others reading this in the future with the same symptoms will have a better clue on what to check.

I lived in Houston for 12 years, btw, SpaceBlonde. Yep, I remember the days of driving through rural Texas and praying my 65 Tbird didn't die on me in the middle of nowhere! :-)

Mr_molsen

Im in the process of replacing my fuel pump. Took it to GM and they told me this was the problem. I trust them (I hope) but my quick disconnect line is killing me. First day on the forum and I just posted about it. Your problem sounds a lot like my problem. I hope you have better luck than I do.

fidde74

My problem started that all my light in the instrumentpanel was lighning... found a engine fuse that was bad..okej..chaenged that one...and now i have other problems..the fan runs with the egnition off. And the damn van starts just like one second and then dies!! wery wierd...dont know what have happend.. Mine is an chevy express converion Hitop from 2003..feels bad that I have only had it for like a mounth!!