HELP PLEASE!!! 1999 Suburban 2500 4x4 won't start...but with a twist

Hi, new poster here...need some help guys!

Ok, about 3 weeks ago after putting in a new battery I woke up to my burban cranking but not starting (not even for a few seconds like other posters have experienced)..went through all the nomal checks for spark and fuel and replaced plugs, fuel filter, ignition coil and ignition control module....to no avail. Went to sleep confused. The next morning I woke up thinking that there must be some sort of theft deterent system that was not "letting" the truck start. After reading about the Passlock system and convincing myself this was my issue, I went to perform the "reset" and the truck just cranked up like normal!!!! I drove away feeling confused and elated at the same time. I have had no problems in the last 3 weeks until yesterday!

:banghead: <----Here I am now, with my truck stuck up at the local grocery store where I stopped to grab some stuff on the way home. Is is misting rain of and on by the way (seemed pertinent to other posters). This time around things are a little different. The Passlock system will not reset when I go through the procedure, as the Security Light on the dash will neither blink nor stay on for any duration beyond the typical 5 seconds after the ignition is turned to the on/run position. I tried to reset the Passlock system anyways...many times at this point, and I can not seem to get the engine to do anything but turn over. Upon further investigation, and surely to further complicate things, my key shows to be a key from the PK3 or Passkey III system...although the year of my vehicle indicated the Passlock system...oh and I also have no original keys, as the previous owner gave me 3 copies with the truck, but no originals.

After trying the reset procedure many times, I disconnected the negative battery terminal for about 5 minutes and rehooked it, hoping to get the security light to stay on...hence "learn" the new code upon reset...but once again I had no luck. I also removed and reinstalled the PCM, hoping for the same results...still have the security light on for only 5 seconds from ignition to on position. The last thing that I did, thinking the new ignition coil or new ignition module could have gone bad...was to check one of the wires for spark...and it was sucsessful, I do have spark to the plugs.

Now I am as confused as ever...not knowing what I should check/recheck next! Please let me know ANY and ALL things that I may check to get this truck started!!!!!

Mark

OK, pulled the code P1351 - Ignition Control Circuit High Voltage (according to Haynes) / Control Ignition System or Misfire (According to Diagnostic Tool)...I am leaning towards the ignition coil and or ignition module...any help is appreciated!

OK, had the Ignition coil checked and replaced the ignition control module with a new one (Autozone gave it to me free becasue they could not check it)...but I am still just turning over..not firing.

I am at a loss here...anyone???????

Is your '99 Sub an "old" or "new" body style. Also need to know what motor?

The 1351 code trouble shooting tree has about 18 steps in it ('98 GM manual) and is too lengthy to detail here. It basically checks for opens or grounds in the IC circuit to/from the control module and the PCM/VCM.

You mentioned a fuel press test but did not state the press readings.

Is your '99 Sub an "old" or "new" body style. Also need to know what motor?

The 1351 code trouble shooting tree has about 18 steps in it ('98 GM manual) and is too lengthy to detail here. It basically checks for opens or grounds in the IC circuit to/from the control module and the PCM/VCM.

You mentioned a fuel press test but did not state the press readings.


Stickman,

Thanks for the post....my sub is the old ('91 I think to '99 bodystyle), with the Vortec 5.7L 350. I do not have access to the troubleshooting tree that you aretalking about, but woulds love to get a copy of it.

I have not been able to check the fuel pressure yet, as I am lokking for a guage to work on the schrader valve on the fuel rail...I will let you know when I get a reading.

I forgot to mention that I have also replaced the rotor and cap.

Tonight I will be installing the Crankshaft positioning sensor AND the camshaft positioning sensor and hoping for the best...if that does not do the trick I'll be bangin' the head on the brick wall again.


Thanks again for the response!

:runaround: OK, the Camshaft and Crankshaft positioning sensors have now been replaced...and the truck is still cranking like mad but not firing...I am really thinking the fuel pump or the fuel pressure regulator may be the problem...a friend of mine is bringing a fuel pressure testing kit later this week to check the pressure.

Does anyone else have any other suggestions?????

Thanks in advance!

I had a similar problem a while back on my '94. I changed a power steering hose and went to move the vehicle and it would crank forever. I was scratching my head for days diagnosing everything under the hood. New plugs/wires/cap/ etc etc. Even changed the fuel filter.

Just so happened by some odd coencidence the fuel pump decided to crap out on me.

You said your leaning towards the fuel pump.. a quick test with out a press gauge.. dump a shot glass of gas in the carb. If it starts, runs, then dies.. Its your fuel pump.

I've seen this problem a few times with these trucks, check the conection at the fuel pump, it might be bad so the fuel pump wont work most of the time or at all, a lot of people changes the fuel pump but doesn't change the conection harness and that can be a big deal, the original harness usuali fails on tahoes and suburbans, start checking the fuel pressure or try listening to the fuel pump you should be able to hear it, good luck.