Hate to ask the obvious but are you displaying any codes? I didn't see any mentioned. If you don't know how to pull them, go to your data link below and to the right of the steering wheel, make sure your key is in the off position, jump A & B (the top two on the right), now turn key to run position (don't crank motor) and your Service Engine Soon will start flashing. These are the DTCs (Diagnostic Trouble Codes) It wil flash the first number, pause and then the second number (e.g. one quick flash, pause then two quick flashes for a DTC 12). By the way, if you get a 12, there are no codes stored. The DTCs will flash 3 times with the lowest first and progressively higher numbers. Make sure you capture all of them. When the last one has been displayed they will start over. This is as good as I can explain it. I'm no literary genius. When you get the codes, post again. I have a 94 like yours and broke down a bought thefactory manuals. Saved me a lot of time. Worth every dime.

 

Well, I can't speak for the other guys, but my 94 Blazer does not throw any codes...that was the first thing I checked. Like I've wrote earlier, at first I thought it was a fuel problem...replace pump and spider. Then I thought ignition problem...as of last week I've replaced distributor cap, rotor button, module, pickup coil, and the ignition coil. I replaced everything with AC Delco parts...learned my leason a long time ago. So my current situation...NOT TOO GOOD. Its cutting off more often and now, when its cold, it won't run worth crap until the motor is good n' warm. This issue is really making me wanting to pull the rest of my hair out. And what I mean by its not running well when its cold, is its cutting off more frequently. There is no missing in the engine, it just runs then BAM...shuts off. Sometimes it won't start directly back, but wait 30 secs to 1 min and it will.

Oh and by the way...in case I haven't told yall this, thank you very much for your help and all your advice.

Matt

 

If your truck isn't shooting any codes, then let's make it shoot a code to see if the ecu is working properly. Just disconnect the sensor in front of the intake (connected to your air assembly. (Beneath it) Start it. Give it some gas. This should throw a code. It won't hurt anything, and if it does shoot the code, then plug it back up, crank it, and give it some gas. The code should disappear... Also, have you tested your alternator lately? It may show it's charging, but it may be close to failing, like mine.

 

I had an old 1990 Caddy that one time it would run like a champ and then would just barely run, black smoke pouring out of it and ROUGH. Found it was the computer (ECM). Don't know if you can have them tested but it might be worth a try. Used to be there were 3 things that made motors run. Air, fuel and spark. Now it's 4. Electronics being the fourth.

 

Well I had my hopes up until last night. I had an AC Delco Engine Coolent Temp Sensor for the ECM, so I put that in this weekend. At the same time I disconnected the battery for awhile and checked the connections on the cables. I seen a very loose connection on the cable termination so I fixed that problem. My thinking (not knowing about car electrical systems) is that if there is not a good connection through the battery, its going to lead to voltage drop from the lack of a ground being made...???? Well anyways...one of these repairs fixed my problem...until last night. I have put about 75-100 miles on it since this weekend then the problem started again. Is it possible that disconnecting the battery reset something in the ECM then it took 75-100 miles for the problem to come back? Oh and by the way, since cold weather has hit...the thing don't want to stay running at all until it warms up somewhat...does any of this make any sense?

 

Here is another idea I want to throw out there and get some comments on. My volt gauge in the dash is reading pretty high (16-17 volts). For some time I have took it to be a calibration problem on the gauge part. I haven't checked it with a volt meter yet, but could high voltage from the alternator screw up the computer to make it cut the car off....and then start right back?

 

Mine reads the same pretty high but no problems

 

I have a similar prob. Truck used to startup right away, but had a rolling idle. Code 35-IAC, I ignored it for months. Started missing up grades. Last week it stalled. Started, drove a 100ft-stalled. No start, waited 5mins, then it started. Stalled, would not start at all. Walked home and towed it. Replaced a 4 month old fuel pump. Same condition. Replaced the IAC. Same condition. Fixed a disconnected vacuum line-idle sounded better. Drove to store at 11pm. Same thing happened-walked home in 20deg weather.
Autozone cap, rotor, wires, plugs, fuel/air filter replaced in summer. Intake gaskets, 3rd fuel pump, EGR cleaned and SS wire gasket, pressure regulator (cant remember), also.
When I replaced the wires, cap, rotor, the truck ran great. With 146,000mi, I could power brake and smoke the tires until second gear.
I had to take out the dist because of stripped threads for dist cap holddown screws. Not too long, began the missing up hills.
It is so cold out.
1994 S10Blazer Tahoe 4.3L-W, 4Dr, 4WD.

 

Update: Ck pump relay for hot and hot to pump-ok. pressure-ok. Replaced pump pulsator (between pump and steel line) w/fuel hose. Known problems TSB GMC. seemed better until it stalled. Pulled new fuel filter and emptied gas into glass container. Gas was murky and green. Odd. Dump 2-1./2 gal of gas and 8oz of acetone and 8oz xylene. Tank had about 8 gal before this. So far so good. Possible bad gas bought in DE. Story Ive been told, some gas brokers are mixing water and a chem that blends water w/gas. If it isnt done right, you get a tank of mush.