'91 s10, at a loss now.
#1
07-21-2009, 08:17 PM
Join Date: Jul 2009
Location: Coeur D Alene, Idaho
Posts: 26
'91 s10, at a loss now.
I have a 1991 s10 blazer. with a V6 4.3 TBI engine.
My truck hasn't ever given me any real problems until now. I was taking a road trip to my hometown. I was driving along the highway on flat surface when my truck suddenly just died. I pulled over, tried starting it and it started just fine, and I went about another mile, then instead of just cutting off it started to bog down hardcore and I had to stop. It was jerking/bucking really bad while stopping to pull over. ( I was still on level ground and didnt have it under any load ). after i was pulled over it died again.
When starting it again the idle started out rough. it was surging, pulsating. but the pulses of the idle was even. it doesn't go high then low, just a constant surge. I could get it to start and idle that way, but putting it in drive would cause it to buck a couple times then just die.
I'm not a mechanic, but i've had some fairly mechanical savvy friends/relatives look at it and still have no idea.
I took the ECM in to have it tested. It was good. My Ignition coil had some bad resistance so i replaced it. My truck started right up with a new coil, idled fine for 5 minutes, then I drove it about 2 blocks and back to the same thing. Even took the new coil in to be tested and it is still good. Also replaced the rotor in the distributer cap as it was getting some resistance too. Still no changes.
After sitting for about a month with my truck in the other town because i had to leave it there, my cousin changed the Fuel Filter, Air Filter, and put some fuel additive to my gas. It ran fine after that, and a friend of mine drove it 240 miles back to where i live. about 220 miles into the trip, the truck started doing this same exact thing again. After letting it sit for a while it would start up and go a little further. After about an hour, it will no longer even start.
I got the truck towed here so I could find if it would give me any codes. I got 24, and 33. I replaced the MAP sensor as the code 33 suggested. My old one was spiking different voltages. I just put the new MAP sensor in, and it still won't even start. the engine turns over but doesn't want to start. I checked and there is spark, my spark plugs are only about a month old, and my fuel pump is only about 5 months old. Any suggestions on what it may be? Any help would be greatly appreciated as this truck is really starting to get frustrating
My truck hasn't ever given me any real problems until now. I was taking a road trip to my hometown. I was driving along the highway on flat surface when my truck suddenly just died. I pulled over, tried starting it and it started just fine, and I went about another mile, then instead of just cutting off it started to bog down hardcore and I had to stop. It was jerking/bucking really bad while stopping to pull over. ( I was still on level ground and didnt have it under any load ). after i was pulled over it died again.
When starting it again the idle started out rough. it was surging, pulsating. but the pulses of the idle was even. it doesn't go high then low, just a constant surge. I could get it to start and idle that way, but putting it in drive would cause it to buck a couple times then just die.
I'm not a mechanic, but i've had some fairly mechanical savvy friends/relatives look at it and still have no idea.
I took the ECM in to have it tested. It was good. My Ignition coil had some bad resistance so i replaced it. My truck started right up with a new coil, idled fine for 5 minutes, then I drove it about 2 blocks and back to the same thing. Even took the new coil in to be tested and it is still good. Also replaced the rotor in the distributer cap as it was getting some resistance too. Still no changes.
After sitting for about a month with my truck in the other town because i had to leave it there, my cousin changed the Fuel Filter, Air Filter, and put some fuel additive to my gas. It ran fine after that, and a friend of mine drove it 240 miles back to where i live. about 220 miles into the trip, the truck started doing this same exact thing again. After letting it sit for a while it would start up and go a little further. After about an hour, it will no longer even start.
I got the truck towed here so I could find if it would give me any codes. I got 24, and 33. I replaced the MAP sensor as the code 33 suggested. My old one was spiking different voltages. I just put the new MAP sensor in, and it still won't even start. the engine turns over but doesn't want to start. I checked and there is spark, my spark plugs are only about a month old, and my fuel pump is only about 5 months old. Any suggestions on what it may be? Any help would be greatly appreciated as this truck is really starting to get frustrating
#2
07-21-2009, 09:09 PM
I would check the fuel pressure with a fp gauge. You could have picked up debris or water in the tank... try changing the filter again. Run the old one backwards onto your hand and look for "droplets"... if so, that is water... a filter will not pass water.
What brand of fuel pump did you install... cheapies can start acting up in a very short time.
Any exhaust smoke when it does this? How about the cat?.. sure it's not clogged?
What brand of fuel pump did you install... cheapies can start acting up in a very short time.
Any exhaust smoke when it does this? How about the cat?.. sure it's not clogged?
#3
07-21-2009, 10:12 PM
my 93 blazer is doing the exact same thing. Ive had it in to the mechanic and he said it was a clogged egr valve it's the vortec engine not to familiar with this engine he tried to clean it out as best he could and this seemed to help for a few months but it is acting up again.....this time its accompanied with the 'rotten egg' smell the cat looks to be original what would that make it 16/17 years old.... I personaly thought it might be the cat as the previous replyer stated because my cav did the samething.... surging and bronking and rough idle, loss of power,....I had put on a new cat and its running like charm let me know how you make out it sure would help I think we have the same problem!
mark
mark
#4
07-21-2009, 10:23 PM
Join Date: Jul 2009
Location: Coeur D Alene, Idaho
Posts: 26
Thanks for the replies! I had someone suggest the EGR valve to and when I read into it, it sounded almost exactly like what could be causing it to act the way it was. I'll try taking it off and cleaning it out. And I have a friend with the fuel pressure gage so I will be able to check that too.
The entire time my truck has been doing this there is no funny smells at all, or smoke coming out of my exauhst. I don't know the brand of fuel pump that got put in because I had it done somewhere, good thing is if that is the problem they will honor it and fix it for free
I will try all of your suggestions and let you know how it works out. Let me know if you have any other ideas as well.
thanks again!
The entire time my truck has been doing this there is no funny smells at all, or smoke coming out of my exauhst. I don't know the brand of fuel pump that got put in because I had it done somewhere, good thing is if that is the problem they will honor it and fix it for free
I will try all of your suggestions and let you know how it works out. Let me know if you have any other ideas as well.
thanks again!
#5
07-22-2009, 08:46 AM
Definitely check and clean your EGR valve - and get the screened gasket from the HELP! section of your autoparts place.
jacko, your problem seems more to be a fuel leak under the plenum that has slowly destroyed the cat (raw fuel will do that). Fuel leaks under the plenum will clog the EGR with carbon, but that's just one of the symptoms. You need to get it checked by someone who's familiar with the 4.3 CPI engine.
jacko, your problem seems more to be a fuel leak under the plenum that has slowly destroyed the cat (raw fuel will do that). Fuel leaks under the plenum will clog the EGR with carbon, but that's just one of the symptoms. You need to get it checked by someone who's familiar with the 4.3 CPI engine.
#6
07-22-2009, 01:00 PM
actually I took off the plenium today you are right Leanne bravada! there is a puddle of fuel on the DRIVERS side where the fuel lines come into the plenium. There is also a very small amount by thr FPR but the whole inside of the plenium is covered with black deposits no one side cleaner than the other from was out.
What's my next step?
mark
What's my next step?
mark
#7
07-22-2009, 01:24 PM
Black deposits are normal. Sounds like you need to replace the 'nut kit' - the fuel pressure and return lines - and the FPR.
The former are available at NAPA and the latter is available at Autozone, etc - it's a Dorman/HELP! part. Get a new plenum gasket and the screened EGR gasket (another HELP!) part.
The former are available at NAPA and the latter is available at Autozone, etc - it's a Dorman/HELP! part. Get a new plenum gasket and the screened EGR gasket (another HELP!) part.
#8
07-23-2009, 10:24 AM
how do the fuel lines come off? do they just pull off? have not really had a close look yet. Thanks for all your help... Ill need to get my hands on one of those tamper proof torx sockets/screwdrivers to dissasemble. Another question.......those skinier lines "the spider' I believe? what do they do and should I replace them since its right there? I unplugged them and the plastic arms broke off on a couple.... as far as cleaning.... if the black deposits are normal is it really crucial?? time I dont have trying to build a garage and I am really behind due to the rain everytime I have a day off
thanks again
mark
thanks again
mark
#9
07-24-2009, 08:16 AM
No, you unscrew a plate to get them off.
The tamper proof torx bit comes with the regulator when you get the Dorman part, however since you unplugged the spider poppets and broke the retainer tabs, now you do have to replace the spider as a whole. You didn't need to touch any of that...now you don't need that special bit or the FPR separately.
Scroll to the bottom and look at the 4.3 CPI Service Kit - that's everything you need:
http://www.lindertech.com/reconinj.htm
You don't need to clean the deposits out of the plenum, but you do need to clean them out of the ports the EGR valve 'breathes' through and out of the port the IAC 'breathes' through as well.
The tamper proof torx bit comes with the regulator when you get the Dorman part, however since you unplugged the spider poppets and broke the retainer tabs, now you do have to replace the spider as a whole. You didn't need to touch any of that...now you don't need that special bit or the FPR separately.
Scroll to the bottom and look at the 4.3 CPI Service Kit - that's everything you need:
http://www.lindertech.com/reconinj.htm
You don't need to clean the deposits out of the plenum, but you do need to clean them out of the ports the EGR valve 'breathes' through and out of the port the IAC 'breathes' through as well.
#10
07-24-2009, 08:44 AM
No, you unscrew a plate to get them off.
The tamper proof torx bit comes with the regulator when you get the Dorman part, however since you unplugged the spider poppets and broke the retainer tabs, now you do have to replace the spider as a whole. You didn't need to touch any of that...now you don't need that special bit or the FPR separately.
Scroll to the bottom and look at the 4.3 CPI Service Kit - that's everything you need:
http://www.lindertech.com/reconinj.htm
You don't need to clean the deposits out of the plenum, but you do need to clean them out of the ports the EGR valve 'breathes' through and out of the port the IAC 'breathes' through as well.
The tamper proof torx bit comes with the regulator when you get the Dorman part, however since you unplugged the spider poppets and broke the retainer tabs, now you do have to replace the spider as a whole. You didn't need to touch any of that...now you don't need that special bit or the FPR separately.
Scroll to the bottom and look at the 4.3 CPI Service Kit - that's everything you need:
http://www.lindertech.com/reconinj.htm
You don't need to clean the deposits out of the plenum, but you do need to clean them out of the ports the EGR valve 'breathes' through and out of the port the IAC 'breathes' through as well.
Just wondering, a couple of novice questions......
If you need to replace the fpr and associated lines, wouldn't it be best to replace the entire spider assembly anyway? Or do they not 'fail' at the same time/rate as the fpr? How do you determine (symptoms) that the "spider" assembly needs to be replaced?
My fuel pressure is within specs with the key on but drops off completely when the key is off so I suspect that the fpr is bad but don't know about the rest. Haven't taken the plenum off as yet.
TIA
Licklog