hey guys, my 91 4wd 4.3 liter, TBI won't start.

Problem originated while driving, stereo suddenly emitted a loud beep,
everything went dead, car quit. like a surge of power or something.
imediately started back up, and ran really ruff. Drove it a bit, stopped and the car intermitantly ran really ruff. After sitting for an hour, it started...ran fine, and continued to do so for a week or more.

One wet day, it wouldn't start, starter would turn, engine wouldn't fire.
So i let it sit a couple of hours, and it started. I then replaced the DIST. Cap and rotor button, because they were both worn and had corrosion. Ran fine for 2 weeks.

Then one day with a dew it wouldn't start again. took it for a tune up. new plugs, wires, ect. ran fine for a week. sat up for a few days, then wouldnt start. This time it really wont start.

i originally though it had no spark, becuase i used a test light in a
spark plug wire from coil and from distributer and got no light on start.
so i replaced the coil, dist. cap, rotor, new spark plug wires, even the ingnition module.

when it wouldn't start, i began to doubt my initial diagnosis, so i pulled a plug, and grounded it and it sparks. way to go rob. anyway, point is,
i have spark... won't start.

Previously to all this, the car was running great, but smelled like rotten eggs really badly. I have read about a fuel system problem that would cause this, but have no idea how it fits with the rest of the problems i am having.

I hope i have been clear! thanks for any help in advance!

A few things here,
Sound like there is moisture getting in the dist. but how? IF you have spark the next would be fuel or air/fuel mixture.

Check EGR valve, Replaced mine

as for the rotten eggs that would be the converter..

and fuel pump, you should hear it priming when you turn the key, if you dont it is a pain to get to I have replaced mine.

thanks for your suggestions, got some more info:

fuel pump is running at key on.
fuel is being sprayed into the TBI by the nozels when i try to start it,
i can see the gas collecting below them.

I put a voltmeter on the pickup coil as according to HAYNES manual.
flexing the wires the reading jumped around at about 800. manual says it should read steady.

got a new coil, pulled distributer, fought the carbon deposits to get it apart, replaced coil, put distributer back together and in. busted a spark plug though putting it in. Grrrrr. last thing i had to do too, dang it.

going to get one now. let you know what happens.

:/

--rob

When is the last time you did a tune up,

well, got the plug in...
went to fire it up, and it tried to fire plenty of times but wouldn't catch,
sounded like it was backfiring.

I think a timing problem, and started researching. I cannot tell exactly which engine i have. The door panel says nothing about engine type. lable on the back door says 4.3 liter. Haynes manual has a picture of 3 engine types the pic that represents my engine is the 2.8L v6 TBI. the only 4.3L pictured is the CPI.

Still going on the 4.3 we set the spark plug wire up for the 4.3L with the #1 cylinder front right.

The 2.8L v6 #1 cylinder is the front left.

how can i tell exact engine type?

thanks!

I had the same problem with my 1993 s-10 blazer 4.3L vortec. It wouldn't get spark to start so I would pull the cap and rotor and check it and put it back together and it's been starting every time now. I found out there was a pinched wire in the distributor that was lifting the cap up so it wouldn't give any spark until it was unpinched.

The easiest way to figure out which type of engine you have is to check in a Chilton's manual for VIN# statistics. I hope this might help you.

hey madmonk,
i ment to update this post when i got it fixed so others troubleshooting could see what my problem was, but i slacked on it, so here goes...

I had spark, but i wansn't using a spark tester, just grounding it. That is not the same thing as using a spark tester. Also the problem was intermittant, so getting spark sometimes wouldn't rule out the electrical.

I ended up replacing the ignition coil, and the ignition module, just throwing parts at the problem, with no result. I finally tested the PICK UP COIL, and found it to be faulty. The haynes manual says when both leads of a voltmeter are connected to both leads on the pickup coil plug that runs to the iginition module, and the wires are flexed, the voltmeter should read a steady value between 500 and 1500. mine read about 800, but it was all over the place, indicating the part was bad.

so i pulled the distributer unit out, took it apart and replaced the pick up coil. WARNING to the novice though, when i put my distributor back in, i managed to turn the gears a bit, and got the timing WAY off, so it STILL wouldn't start. It was however trying to fire, so i figured i had fixed it. I ended up having to have a mechanic get the timing right. but it fixed my problem and the vehicle even performs better than before.

hope this may help someone!