1990 Suburban won't start

[2000CAYukon]

Originally Posted by YohDave

Thank You. I get spark going to the ignition coil. However, I can't get a voltage reading going to the 4 wire lead going into the ignition module at the back of the distributor. I have checked with a test light and a voltmeter. Any ideas? Thank you.

You need to touch the test light to the ignition module pin for the purple/white wire. It may be easier to take the ignition module to a parts store to be tested.

You can also put your volt meter on the lowest ac scale and connect it to the pickup coil direct. It should generate 1 or 2 millivolts while the engine is cranking.

//2000CAYukon

[YohDave]

I was able to get the right milivolts coming off the pickup coil, but no light on the purple/white wire lead on the module.
I figured it was a bad module, so I took the whole distribuor back and got a new one with a new module. I upgraded the cap to a Borg Warner. Everything back in, still no start and no spark at the plugs. I'm almost ready to give up. Thanks,

[2000CAYukon]

Originally Posted by YohDave

I was able to get the right milivolts coming off the pickup coil, but no light on the purple/white wire lead on the module.
I figured it was a bad module, so I took the whole distribuor back and got a new one with a new module. I upgraded the cap to a Borg Warner. Everything back in, still no start and no spark at the plugs. I'm almost ready to give up. Thanks,

Is the coil getting power? I assume you have checked all the fuses including the fuel pump fuse (near the fuel pump relay).

I have the 90 factory service manuals at home. I will take a look later tonight when I get home and see if I can be of any help.

//2000CAYukon

[YohDave]

You have been extremely helpful!
No, I did not check the fuel pump fuse. If you can point me in the right direction of where to locate it, that would be great.
Up working on it late again last night and I've had some success. Now I have power to the coil and spark in all the plugs. I'm getting the correct MiliAmp reading off the injectors, but still not getting spray. Not enough fuel pressure? Do the injectors need to be re-built? I appreciate your help!!

[2000CAYukon]

Originally Posted by YohDave

You have been extremely helpful!
No, I did not check the fuel pump fuse. If you can point me in the right direction of where to locate it, that would be great.
Up working on it late again last night and I've had some success. Now I have power to the coil and spark in all the plugs. I'm getting the correct MiliAmp reading off the injectors, but still not getting spray. Not enough fuel pressure? Do the injectors need to be re-built? I appreciate your help!!

I have a pickup but the manuals include the suburban. On my truck the fuel pump fuse is under the black cover on the passenger side of the firewall. Not sure if is in the same place or not on yours. There is also a fuel pump test connection that bypasses the relay and fuse so that you can test the pump directly. I forget where it is (never used it) but I know it has one.

Unfortunately, the TBIs don't have a test port in the fuel line so it is hard to test the fuel pressure. You need a tool that replaces the fuel filter so a gauge can be hooked up. Pressure needs to be 9 - 13 PSI. If you have not replaced the filter, that would be a good thing to check (or just replace it).

I won't be home for a couple of hours but I will try to find where the test connection is for the fuel pump. You should be able to hear the pump when you apply 12 volts to the test connection.

//2000CAYukon

[2000CAYukon]

The test terminal is part of the ECM connector under the steering wheel. See http://www.troublecodes.net/GM/ and apply fused 12 volts to pin G.

There is an oil pressure switch that can cut off fuel if the oil pressure is too low.

The fuse is under the black cover.

If you have an injector test light, does it flash when you try to start the truck and it is connected to the injector harness?

Good Luck,

//2000CAYukon

[YohDave]

Thank you for getting me the info. Finally I was able to get pulse going to the injectors and fuel getting up to the throttle body. However, I'm still not getting spray. I started to take the TBI apart and found most of the seals/gaskets were almost worn away completely. When I put it back together I had leaks everywhere. I'm going to try a TBI rebuild tonight (I had to wait for the tune-up kit) and see if that corrects the problem. Would you suggest also replacing the fuel pressure regulator while I'm in there? Thank you again for all your help! Do you know the specific tool I would need to check the fuel pressue? That is something that I don't have.

[2000CAYukon]

Originally Posted by YohDave

Thank you for getting me the info. Finally I was able to get pulse going to the injectors and fuel getting up to the throttle body. However, I'm still not getting spray. I started to take the TBI apart and found most of the seals/gaskets were almost worn away completely. When I put it back together I had leaks everywhere. I'm going to try a TBI rebuild tonight (I had to wait for the tune-up kit) and see if that corrects the problem. Would you suggest also replacing the fuel pressure regulator while I'm in there? Thank you again for all your help! Do you know the specific tool I would need to check the fuel pressue? That is something that I don't have.

I got a rebuild kit from Kragens that had a new regulator in the kit. The regulator is located in the TBI itself.

If you don't already have a fuel pressure tester you can get something like http://www.actron.com/product_detail.php?pid=16175 (but the fuel tester will only work with the adapter that it came with. The threads are different so you need to understand that if you buy this gauge).

If you already have a gauge, then you can get something like http://www.sjdiscounttools.com/ta37650.html

Good luck.

//2000CAYukon

[YohDave]

I think I'm going backwards. I finished the TBI re-build and had some difficulty cranking. I figured it was the starter, which I then replaced. Now I can't even get it to turn over all the way (I might get one good turn, then I hear the clicking sound). I know I have all the starter connections on and tight because I took my time. Maybe a bad starter? Kragen usually has ok parts, but I already had to exchange a distibutor that I got from them as well. Any thoughts?

[2000CAYukon]

Originally Posted by YohDave

I think I'm going backwards. I finished the TBI re-build and had some difficulty cranking. I figured it was the starter, which I then replaced. Now I can't even get it to turn over all the way (I might get one good turn, then I hear the clicking sound). I know I have all the starter connections on and tight because I took my time. Maybe a bad starter? Kragen usually has ok parts, but I already had to exchange a distibutor that I got from them as well. Any thoughts?

Clicking usually means there is not enough power to turn the engine over. Double check the battery connections. Make sure the battery is fully charged.

Does it click if you try to jump start it?

//2000CAYukon

[duduca]

your head light seems to be ok or when the problem occurs the interior main ligh turn off?

[YohDave]

Yes. Headlights and Interior lights are fine. The battery has a full charge (I just replaced it as well) and I tested it to make sure it was throwing the right voltage.
Still not getting it to turnover. It sounds like it wants to go and I'll get a few good turns out of the belt, then it will stop.
Someone mentioned it may be head gaskets and not enough compression. Any thoughts. Thanks again!

[2000CAYukon]

Originally Posted by YohDave

Yes. Headlights and Interior lights are fine. The battery has a full charge (I just replaced it as well) and I tested it to make sure it was throwing the right voltage.
Still not getting it to turnover. It sounds like it wants to go and I'll get a few good turns out of the belt, then it will stop.
Someone mentioned it may be head gaskets and not enough compression. Any thoughts. Thanks again!

To me turnover means the engine is not moving at all when you turn the key on. So does the engine move at all when you turn the key?

The timing chain may have jumped a tooth (or two). I replaced mine last year (115K on my 90 GMC K1500 Sierra) and it was pretty loose.

By all means, a compression check would be a good thing to do at this point.

//2000CAYukon

[YohDave]

I get about one full rotation out of the Serpentine belt. Then the clicking sound even with jumper cables on it. Thats about all I can get. If I turn the distributor I might get 2 or 3 rotations out of the Serpentine belt, and then back to clicking. Sorry I was unclear about turnover.

[twistedtech]

I just read so much here that 2 things just happened.1,I have a headache now,2 I completely forgot all that you have done,what your problem is or was or still is with new ones.If I recall you have a big block,sounds like you crancked the crap out of your starter,that's alot of engine to cranking as much as you have done.Could you please put up a short list of : Issues now,before starter explosion.The starter issue was caused by not getting it to go and winding the crap out of it so it don't count as an issue,it is actually a result.I love the older chev stuff and will help you as will the rest of us,just slow down dude.I get the impresion your going 300 mph.