Rough idle gas fumes from tail pipe 1993 jimmy s-15 vortec

[rabbit2475]

here is my problem. the other day I was driving down the street and had a quarter tank of gas. looked at my gauges again a few minutes later and it said that I had no gas left, so i stoped put some in and it worked fine(thought the gauge was going bad) then the next morning I drove it to work with no problems at all, but when I went to go home and started it, it was running very rough!!! tryed to excelerate but was having a very hard time with it. so I looked under the hood and saw one of the plug wires were arcing. so I replaced all the wires(I had just got this car a month ago from a friend and wasnt sure how old they were) and the problem was gone, took it on the freeway and had great power. so i parked it for the night and went to the jimmy the next moring and it was having the same problem, but this time it was blowing white smoke out of the tail pipe, I went back to check this out and it smelt like gas, then I opened the hood and was making sure that i had all the plug wires on, tried the driver side first and it seemed fine and cool, went to the passenger side of the engine and it was very hot, went back to the other side and saw that there was gas leaking were the manfold connects to the pipe to the back. so I took off the distributer cap and checked that thinking that I was having a sparking problem and it was fluding out the cyclenders on that side but everything was good there, checked the coolant level thinking maybe I blown the head but it was full, then I checked the oil to see if it was at the correct level and found fuel mixed with the oil, and the dipstick was reading over the full line. does anyone have any idea whats going on here..I've started it a few times since this happening and sometimes it has this problem of no power and fuel out of the tail pipe and some times it works just fine....it so on and off... a friend said that his car once had a simaliar problem, but his throtle postion sensor had went out and put fuel in his tank and flooded his system?? any ideas??????

[rabbit2475]

well I changed the oil and filter in it and got myself a book
runs very smooth now but still has a bit of white,moist,gas smelling smoke coming out of the tail pipe. 'im starting to wonder if the head gasket is bad???? this stupid book I bought doesnt say how to change it

[GMMerlin]

I would check the CPI unit and the fuel lines that feed it for leaks.
If the leak is severe enough, it could fill your crankcase with fuel.

[rabbit2475]

I had the codes check at auto zone and they said that the map sensor was runing low voltage and the oxygen sensor was not responding.

[dolfo]

It sounds like your fuel injector pressure regulator is leaking.If that's the case you will not have any change in the oxygen sensor voltage since it is trying to lean out the machine and there will be no voltage change.

[rabbit2475]

well I've checked the map sensor and that seems ok, changed the oxygen sensor(computer said it was bad),spark plugs, plug wires, cap and rotor, TPS, checked something(sounds like I-AK) worked good. Wasnt getting much power so I found the altenator to be bad, so I changed that, so today I decided to try to replace the ECM, and I'm hoping that it fixes this problem once and for all!!!!!!!!! anything else i could be missing?????????

[NJTy180]

Originally Posted by dolfo

It sounds like your fuel injector pressure regulator is leaking.If that's the case you will not have any change in the oxygen sensor voltage since it is trying to lean out the machine and there will be no voltage change.

but he would also end up with gas in his oil, so if that were true, check the oil and see if its "watery" and if it smells like gas.

[rabbit2475]

it does smell like gas....there is alot of fuel in the oil

[NJTy180]

Originally Posted by rabbit2475

it does smell like gas....there is alot of fuel in the oil

then its definately the fuel pressure regulator. stop driving the truck immediately before you kill the bearings and replace that regulator.

Next, do an oil change with a "cheap brand" motor oil and filter, drive it for about 100 miles, the do another oil change with your normal oil and filter.

[rabbit2475]

Well I Tried the fuel pressure regulator ( really spendy!!! 380.00) and changed the oil and it was working great, started up without having to pump the gas(which is weird becuse I have the cmfi system) drove it around about 100 miles without any gas (white smoke smells like fuel) coming out of the tail pipe, then I thought it was all fixed!. I tried to drive it about 4 hours later and once again there was white gas smelling smoke, and no power.
So back to the drawing board I went, I started with a compression test on the cyclenders(SP??) and got 140#s on each on of them(thought maybe I was getting blow by or had a dead cyclender)that all seemed to be good so next i moved on to the fuel pressure test and got 52psi which is a little low.
but doesnt seem like that would be something that would be making to much fuel pump thru the system????? So then I thought maybe I'm not getting enough spark to burn all the fuel, so I went and replaced the coil....I'm really out of answers but I would really love to get this thing working again.. Ohhh one more thing i'm getting a code from my computer that says the vaccumm control silenoid is not working correctly???( but this is a fairly new code now..) Just to recap the things I have replaced: cap and rotor, spark plugs and wires, altenator,battery, throttle position sensor, oyxgen sensor, computer, map sensor, battery cables and terminals, fuel filter, CMFI system(includes a hold bunch of things like fuel injectors and system,fuel regulator ect..)I also changed out some vaccum lines that were cracked or leaking. Can anyone think of anything that it may be?????

[mjohn]

How about the ERG valve...
This could be clogging...and needs to be cleaned...

Check this thread or the thread for Blazers 4.3 W series...there is much information on this problem...read all you can on this forum before you do more spend more...you will find the problem and ecome educated about the problems with this engine...

[djcarter]

Originally Posted by mjohn

How about the ERG valve...
This could be clogging...and needs to be cleaned...

Check this thread or the thread for Blazers 4.3 W series...there is much information on this problem...read all you can on this forum before you do more spend more...you will find the problem and ecome educated about the problems with this engine...

where is the site on this? and how do you check this thread on this problem with jimmy. i have a 93 jimmy that is having same problem was told it was my fuel injection system (spider) and part cost 480 only from gm dealer .. my truck still sits ..mechanic told me not to drive it cause he took 3 capfuls of gas out of my oil and i could blow my engine if i keep driving it..i would like to know how i can tell if hes being honest with me ? is there a way to check this.? thanks donna

[mjohn]

Donna go back to the page automotive forums by double clicking Automotiveforums.com at the top of this page....then also on the top of that page or in the lower right there is a box Search this site for:

enter CPI Unit...and hit search...start reading the replies...you will learn about the fuel injection system and repairs...and you will read about your problem...let us know here what you find...learn...ok? MJohn

[djcarter]

I Have Read Almost All Of Those..i Found Out That The 4.3 Is A Piece Of Junk..so Many Different Problems All Related To Fuel System.. Even Garage Says Those Engines Have Alot Of Problems They Need To Be Recalled So Everyone Can Be Happy .. I Think My Next Vehicle Will Be An Older Vehicle Like A 70 Chevy Or Something ..lol At Least On Those They Re Easy To Fix And Not Complicated..thanks For The Replies Ill Pry Keep Reading Up On It Cause Winter Coming And I Need To Fix My Truck..just Hate To Spend Money On A Part That It May Not Really Need

[burninjimmy]

yes what they're saying cpi is bad i just went through cpi hell and running stronger than ever
480 sounds steep i got mine through consumer auto parts reman for 175.00 gasket was only 7.00
did it in only 30 minutes runs like a champ!