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I finally got the new injectors and installed them. and you were right my old ones were leaking in several places and the injectors also seemed to not be able to spray very good. my mpgs are back and my truck has more a lot more pep. thanks for the help
I decided to clean my air flow sensor because i recently cleaned and re oiled my air filter. it didnt seem to make much difference but while i had it all apart again I decided to check out under the throttle body again. this time it smelt pretty strong of gas and I looked with my flashlight again. only this time i looked more at an angle towards the firewall. it looked alot wetter to the point that i could see silver parts of the intake.
So just for the heck of it i decided to hook up my pressure tester gauge again and see what happened. It pressured up like normal and while i was waiting to see if it lost pressure something started randomly clicking. it would do it in bursts and then stop for a time and then do it again. as I watched the gauge with it clicking when it clicked the pressure would go down. the only thing that i can think of is that my injectors are opening when they are not supposed to.
From what I understand the poppet valves on this system open and open and close with pressure. GM put out a updated version that makes it more of a mpfi with electronic injectors instead. the injectors are under the top part of the intake manifold. this upgrade is supposed to be much better than the poppet valves and if thats what i need to do I would rather just replace them mostly because it seems like a lot of work to go in and just replace one smaller item and have the chance of haveing to do it again.
My fuel trims are about the same. at idle the short term trims climb as high as -11 as well as the long term fuel trims. if I am going 30 or 40 mph down the road the short term are around -5. and at 65mph the short term trims are 0-4 almost always negative hardly ever positive. It seems the slower I am going the more gas it has to take away. the faster Im going the better it gets.
I am using a scangauge 2 so I always have access to the trims and other info. the trims also seem worse if its a little colder outside.
I looked at the EGR valve and I think the liquid may have just from when i changed the thermostat.
I decided to hold off on the injectors just because they are like $300 for my truck :/. I got a fuel pressure tester that was on sale at my local napa. my fuel pressure is in spec and the pressure didnt bleed down. but one thing that i was wondering about. wouldnt that just diagnose if the regulator was leaking or not and not the injectors?
I replaced my front O2 sensors. one had 230,000 miles im guessing on it because it was original equipment and wasnt the updated part. and the other was a different brand with who knows how many miles on it. I repaced them with GM original ones. I also replaced the coil that tested out of spec on resistance.
my truck has better acceleration and slightly better mpg but its still way rich and it seems like the shaking at idle has gotten worse.
I did notice that around the egr valve it had a liquid coming out of it. that should be sealed off shouldnt it? could that make it rich? if it was a vaccuum wouldnt it be lean??
I’m not sure why that didn’t cross my mind but thank you. I took the intake off and looked into the throttle body with a flashlight and I can see two fuel lines one to bank one and the other to bank 2. And both were wet and I could smell gas. There were also 2 or 3 small puddles of fuel on the bottom of the intake. The vortec has the fuel regulator and injectors under a plastic cover under the throttle body. So I’m guessing that’s probably my best bet of the problem. But is there anything else I should look at?
I did some adventuring today and discovered a couple things.
I checked once for for vacuume leaks and again didnt find any.
my boss thought maybe my distributor worked loose and maybe turned a little. I checked and its pretty tight and I couldnt move the distributor.
I was thinking and decided that I had replaced all the ignition parts except the coil which I had tested before and found that it failed a resistance test but i didnt have the money then to replace it. if that was the problem it would make sense because it wouldnt produce a good spark to burn all the fuel making it rich. if that theory makes sense. it does in my head anyway.
I decided to look at the k&n air filter I have in it. It doesnt look bad by any means but I dont think it will hurt to clean it.
I did a compression test on 4 of the cylinders (thats all the time I had before an appointment) and all four were in the 135-140psi range. the spec on these motors is no less than 100 psi and no less that 70% of the highest. but I dont know that it would be ok to have that much variation. I had always heard within 10% of the other cylinders.
I looked through the plug wires adn there wasnt any noticable arcing or rub spots.
I am still questioning the O2 sensors a little bit but they seemed to respond to a unmetered air and extra fuel.
Last but not least I noticed a small wet spot under my brake master cylinder. upon further inspection it was indeed brake fluid. the brakes on this truck are something that I have been chasing ever since I bought it. I have replaced almost every part of the brake system other than a couple lines, the booster, and the adjusters/springs for the drums. I just replaced that master cylinder last year. but it came from a place where I have had several parts now go bad prematurely. and I am not the only one. I do not shop there anymore and a new napa auto store has moved into the town so thats where I get my autmotive parts now. or online. havent had any problems yet and iv heard they have great customer service plus I know the family that runs it.
So my first adventure is to replace the master cylinder again. I was wondering if it was possible that something to do with brake fluid in the booster was hurting my mpg?? it is hooked directly to the intake vaacuume. I hope to have the master cylinder bench bled and on this saturday.
Ok thanks. When it warms up some ill take a look at it. I think I’ll just go ahead and replace the hardware though. The job was tons easier since I did the axle seals at the same time and didn’t have the hub in the way
Correct me if I’m wrong but wouldn’t a negative trim mean it was trying to take fuel away? Or do I have that backwards? I checked for vaccuume leaks today but couldn’t find any. I watched my O2 sensors they seem to be switching. Although one got stuck and would only switch between 2 and 8 for about 5 seconds. If I turn the key on and nothing else my O2 sensors seem to be random. Sometimes they will match and be at 43ish and stay and sometimes one will be way different than the other and almost bleed off. Sometimes one will read 0 for a short time. I didn’t think it should but I don’t know that for sure.
The scan gauge is hooked right up to the obd hookup so I would hope it’s accurate. But there is a point it’s not over heating so I’m not going to worry about it to much I was just curious
ok. I just talked to the people that put them on and they want me to bring my truck in tomorrow and they will look at it. I will probably air the tires back up for the trip down. I didnt know there was a break in period but that makes sense.
the original tires were actually 245/75/16 i believe. but i put the 31×10.50×15 on it. thats what i had on it before these tires and they were wearing fine. I dont know how wide they are though I got the rims second hand and didnt realize that was a factor.
I will go tomorrow after work and see what they say thanks
I have some new rotors and pads coming this week. I’m going to start there and work back. Today I stopped on a uphill grade at a intersection with my rear tires on a patch of ice and my front ones on asphalt. With the brakes lightly pressed my rear tires spun on the ice so I smashed the brakes harder. I had to push the pedal pretty hard to get the rear to brake but they did brake and the weird thing is the pedal seemed a lot harder after that. I’m thinking they need adjusted again or the adjusters aren’t working. When I’m doin the brakes I might as well pop the rear ones and see what’s going on and go from there. Hopefully that will get done right before Christmas 🙂
I have some new rotors and pads coming this week. I’m going to start there and work back. Today I stopped on a uphill grade at a intersection with my rear tires on a patch of ice and my front ones on asphalt. With the brakes lightly pressed my rear tires spun on the ice so I smashed the brakes harder. I had to push the pedal pretty hard to get the rear to brake but they did brake and the weird thing is the pedal seemed a lot harder after that. I’m thinking they need adjusted again or the adjusters aren’t working. When I’m doin the brakes I might as well pop the rear ones and see what’s going on and go from there. Hopefully that will get done right before Christmas 🙂
the rear brakes do work. the other day on my way home i stopped on a slight uphill grade to talk to someone and left my foot on the brake (not real hard) and the truck in drive. my brother in law noticed that my rear tire was still turning in place because of the snow. so i mashed the brakes harder and it made it brake. I guess either way i need to take a look inside of there on the rear ones. I think ill probably just replace the pads and rotors because the pads are about shot anyway.but that does make sense to start on the front. I do have a rubber hose going from the wheel well to the hub that the rubber has split open and the braided (i think its braided) steel is showing that is on my list to fix this week. but i think for the most part on my truck the rest of the brake lines are metal. ill have to look over them though soon hopefully when i can find a spot thats not a muddy wet mess. thanks
the rear brakes do work. the other day on my way home i stopped on a slight uphill grade to talk to someone and left my foot on the brake (not real hard) and the truck in drive. my brother in law noticed that my rear tire was still turning in place because of the snow. so i mashed the brakes harder and it made it brake. I guess either way i need to take a look inside of there on the rear ones. I think ill probably just replace the pads and rotors because the pads are about shot anyway.but that does make sense to start on the front. I do have a rubber hose going from the wheel well to the hub that the rubber has split open and the braided (i think its braided) steel is showing that is on my list to fix this week. but i think for the most part on my truck the rest of the brake lines are metal. ill have to look over them though soon hopefully when i can find a spot thats not a muddy wet mess. thanks
They are floating calipers. Don’t get me wrong they work they just aren’t as efficient as they should be. The truck I drive for work is one year older and the brakes are a million times better. I have greased the pins before about a year ago. Currently I think my plan is to start with the rear brakes and put in new adjusters and springs and all that fun stuff and maybe try swapping the drums I have never thought of that. Then I’ll work to the front with rotors and pads and see if that fixes it.