I have a 93 S-10 Blazer 4 door 4x4 4.3 VIN W Vortec.

A year ago, I put in a new Delco fuel pump, filter, and strainer, in a good used tank.

About 4 months back, I put in a new Delco fuel pump relay.

Not long after, I replaced the coil with an MSD coil (the old one was breaking down) and installed a new Delco module, pick up coil, pole piece, shaft, cap, and rotor, after noticing some minor driveability issues.

It developed a surge, especially on acceleration, and would cut out, but take off and keep running. I finally traced that down to a bad fuel injector harness inside the intake (I should have found it sooner, I've seen it before). I put a new Delco pigtail in the harness, soldering and heat shrinking it for a permanent weather tight repair.

We drove it for a couple of weeks, and it ran great. So we took it on a trip. It made the 660 mile trip down flawlessly. About 100 miles back toward home, after I stopped to fill up, it ran for about 5 miles, then began to surge, eventually shutting off. It wouldn't start back. I checked fuel pressure and had plenty, I checked spark, and had a great spark. But I had no way of checking fuel injector pulses. So we towed it to a friends house, I was lucky to have one close by. After 3 hours of poking and prodding, I found nothing. All of the sudden, it fired right up and ran fine.

Not trusting it, I grabbed a rental, drove home, and let it sit. I brought it home this weekend, put it back together, and it runs. But I don't trust it. I've got diagnostic tools I'll keep in it, but I really don't want to get stranded again, I have neither the time nor the patience. I also don't want to just go buy a new Delco injector spider for $300 and a new ECM for $100+. Anyone been through this before? It just surges, loses power, and shuts off, then won't start for hours. It has fuel pressure and good spark, but I couldn't check for injector pulses. I was thinking that maybe the injector harness problem hurt the injector drivers in the ECM, but it drove over 1000 miles with no problems before it quit.

 

After all that engine went thru there were no codes thrown at all??

 

Never once. The SES light never comes on unless it is during the engine start-up or key on engine off. No codes.

 

bummer.....i take it you've done the paper clip thing and the light blinked 12 three times...that will tell you a lot if it doesn't....this is definetly an intermittent problem, obviously...the service manual says that 90% intermittent problems are bad connectors, bad grounds & vacumn leaks....lot of help, huh...under the "driveability symptoms" : Engine cranks OK. but does not start for a long time. Does eventually run, or may start but immediately dies. It says to check the Engine Coolant temp sensor, which I would have never have thought to check or the TPS Sensor. Just for girins, start it, if it will, let it idel and pull the TPS connector off. The engine should rev to high rpms. See if it throws the right code or throws one at all. If it doesn't, that would tell you a lot. Also check the Alternator output. Its got to be above 9v. If it isn't that affects the whole system. Sorry couldn't be of more help, this intermittent thing is a real pain......

 

I have a scan tool, I've checked it for codes. I used to be a service tech, I gave it up to work on race cars because I hate this type of crap.

The other problems I've had have been easy to find and fix. This is the 4th of these little trucks we've had, and I like them. I ran into the injector harness thing before, on the one I gave my daughter, that's why I should have caught this one immediately.

I have a theory that it hurt the drivers for the injectors in the ECM, but I'm not sure. I like the truck, but I'm not throwing money at it.

I've been down the trouble tree, I guess I'll just have to catch it not starting and see what it is.

 

For those interested, it ran for about another 3-4 weeks, total, before it finally gave trouble again. I managed to get diagnostic tools connected, and it turns out the CPI injector was failing. It finally failed completely about a day later. The part was replaced with a new GM injector, and the truck runs better than it has in a long time.

 

so by cpi injector, is that also called the spider injector? just curious. I honestly cannot beleive gm never did anything about these injectors, because everyone i have talked to with a vortec has or has had problems with them. thanks

 

Yes, that's the spider. There's nothing they can really do, it's a design flaw, and it isn't reversible, since the flaw is mounting an electronic component INSIDE the hot and nasty intake manifold.

The trucks run great, it's a shame they were so stupid as to do it the way they did it.

 

yes the cpi is also the spider , I have a spare one because I thought mine was bad and it was not , it was the wires that go to it . It took me a little while to figure it out , but there was a little break in the wire .