Mechanic help needed asap..please.
 

Over the past couple of weeks my truck has started to backfire. I have a 98 2 door tahoe with a 5.7 liter vortec. Well Today, along with the master cylinder I went ahead and replaced the spark plugs and wires, and fuel regulator...but it still keeps back firing. It happens mostly when I take my foot of the gas, it starts to do it very rapidly, and its Idling ruff.. when I have my foot on the gas, it doesn't do it that much..it also acts like it wants to die on me every so often..I`m dropping it off at the shop tomorrow, not sure whats up with it..I `m thinking the compression is off, or the fuel pump..I also noticed that I had a hole in my muffler, while I was bleeding the breaks maybe thats the reason? I dont know...and Ideas ?

Probably not fuel pump. Sounds more like timing.

Do you mean the timing belt? or is this something else ? and do you know how expensive this might be?

the hole in the muffler is probably just popping when you let off the gas and the unburned fuel gets there and ignites with the oxygen from the hole
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Fuel pump, vacuum line, coil, water in the gas, etc. Start with the cheap stuff and throw in a bottle of "Yellow heat" and check under the distributer cap for any condinsation. You didn't get the engine wet at any point in the last week or so, did you?

I wondered why everybody was jumping under their tables in the Dotte. The ol' Tahoe backfire.

Possibly spider injector.

Would that cause it to Idle ruff also, and act like it is dying?

No water in the engine lol. I replaced the distributor cap today when I did the tune up and didn't see any water. It has new heads on it and a new intake manifold..but I did notice when I took the top of the fuel injector off that it was pretty dirty, didn't know if that was from the fuel modulator that I replaced being bad or not.

That would be funny if ...........If I didnt live in Johnson County. ;)

I would still go over to the store and invest in a $1.00 bottle of Heat. Get the Heat in the yellow bottle. One of my rigs was doing about the same thing last week and that cleared it right up. A little water in the gas will raise hell with the way it runs. It will only cost you $1.00 to find out.

Thanks..On my way right now.

Those engines, (while great) are notorious for having the valve guide seals leak and go tits up. It doesn't sound like this is the case here but some of the symptoms are consistent. When you start it up, does blue smoke come out of the exhaust?
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No..I looked for that also.

Well shit....

I'm thinking you have an ignition problem then. Likely a bad coil pack/distributor or your timing is screwed.
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ditto

I'm wondering if the timing chain jumped a tooth or two.

I'm thinking more along the lines of it's not really out of time, but the 'puter thinks it is because of a haywire sensor or something.

Do you know how expensive that might be if its the timing? or a bad coil pack?

My suggestion is to go to autozone and get a code reading. (free) They'll tell you what the code means and what parts are likely to be bad, and how much those parts cost.

I`m thinking the same thing...or at least my pockets are hoping its just that lol.

First thing in the morning..thanks. I`m going to get some Yellow Jacket? or what ever its called also. Thanks for all the help fellas, greatly appreciated..

Heat in the yellow bottle.

http://www.omahabiodiesel.net/images/heetyellow.JPG

I would get the compression checked before you spend too much money on all the little things. Also a leak down test might be in order. Good luck either way.

UPDATE.. Took my car to autozone this morning..10 codes popped up in the computer.lol..dropped it off at the shop today..Intake gasket was bad, and I had a vacum leak...total bill was $311.06..after dropping $225.00 the day before on tune up, brakes and fuel regulator..oh well, my truck should run like a champ..if I can afford gas this week lol.

Good for you! My bro's 98 Dakota was coughing and not wanting to keep running. Had to replace a cracked vacuum boot off the intake, and that was that!

Glad you're good to go. That old horse is worth it. Hopefully, it will keep you on the road for a good while.

Tisk tisk, that was one of the things I told you to look for no? Hey, at least your outfit should run like a champ now.

ROFL i came on here because i got the same unit with the intake gasket leaking and the upper plenum o ring around the injector plug in leaking vacuum. ran just like what you described. and that a pretty good price dotte

I don't believe Nissan has been around that long.

If I cant fix it..I take it to Able Automotive. I`ve taken my cars there for over 10 years..they always give good rates and do great work...I was actualy thinking of selling it but it only has 120,000 miles and its a 2 door tahoe..man its my baby..can`t let her go lol.

ROFL in armourdale? i've known bob greiner my whole ****ing life. if i had a dollar for every time he called me "young man" i would be a rich guy. my cousin DJ worked for years in his son's shop fixing torch heads.

ROFL..Yup..those boys do good work... I dont trust any else...


Able automotive"beep beep..somebody knows us ..lol.