Backfire from a fuel injection. Need Help BAD!!!!!!!!!

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Sep 14, 2011 | 06:01 PM
  #1  
I have '87 LS Camaro 2.8L Crossfire multi-port fuel injected v6. One day while driving home the car started having problems idling and would not run unless you keep your foot on the gas. I assumed it was a bad vacuum line since none were properly connected to begin with. So I took the car to my mechanic who said it was no problem but it was gonna take time to fix. One year and $600 dollars later I got my car back with every single vacuum line plugged even my windshield whippers were plugged. Now the car barely idles back fires as soon as u give it gas and with the pedal to the floor I can't go faster than 35-45 mph top. When I went back to mechanic he said it wasn't his fault motor should run fine. So I need some serious help. Jesse
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Sep 14, 2011 | 08:53 PM
  #2  
Re: Backfire from a fuel injection. Need Help BAD!!!!!!!!!
first you got ripped off 2nd tune up parts or new ICM.
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Sep 14, 2011 | 09:45 PM
  #3  
Re: Backfire from a fuel injection. Need Help BAD!!!!!!!!!
Quote: first you got ripped off 2nd tune up parts or new ICM.
I know but what kind of tune up parts/ICM
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Sep 14, 2011 | 10:21 PM
  #4  
Re: Backfire from a fuel injection. Need Help BAD!!!!!!!!!
only time mine ran like that it was a bad ICM but dunno on your other pats, if old, do em too.
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Sep 15, 2011 | 05:15 AM
  #5  
Re: Backfire from a fuel injection. Need Help BAD!!!!!!!!!
It took him a year and $600 to plug your vacuum lines??? I would've had the BB on the phone long before things got that far...fix the vacuum lines the right way, then check the timing, if neither of those do it, have the ICM tested.
And some of those vacuum lines are really important, you can't just go indiscriminately blocking them all off, I mean christ the guy didn't even know the difference between the vac line and windshield fluid squirter lines...things like FPR vac line, brake booster line, the one going from VC to MAF tube, and the PCV are all important for the engine to run correctly, well the brake booster line itself isn't, but your brakes need it, and the engine side def needs to not suck air there to run.
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Sep 15, 2011 | 08:10 AM
  #6  
Re: Backfire from a fuel injection. Need Help BAD!!!!!!!!!
Quote: It took him a year and $600 to plug your vacuum lines??? I would've had the BB on the phone long before things got that far...fix the vacuum lines the right way, then check the timing, if neither of those do it, have the ICM tested.
And some of those vacuum lines are really important, you can't just go indiscriminately blocking them all off, I mean christ the guy didn't even know the difference between the vac line and windshield fluid squirter lines...things like FPR vac line, brake booster line, the one going from VC to MAF tube, and the PCV are all important for the engine to run correctly, well the brake booster line itself isn't, but your brakes need it, and the engine side def needs to not suck air there to run.
Fixin my vacuum lines is my main problem. My lines are butchered and I can't make heads or tails of what goes where now.
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Sep 15, 2011 | 08:11 AM
  #7  
Re: Backfire from a fuel injection. Need Help BAD!!!!!!!!!
Quote: It took him a year and $600 to plug your vacuum lines??? I would've had the BB on the phone long before things got that far...fix the vacuum lines the right way, then check the timing, if neither of those do it, have the ICM tested.
And some of those vacuum lines are really important, you can't just go indiscriminately blocking them all off, I mean christ the guy didn't even know the difference between the vac line and windshield fluid squirter lines...things like FPR vac line, brake booster line, the one going from VC to MAF tube, and the PCV are all important for the engine to run correctly, well the brake booster line itself isn't, but your brakes need it, and the engine side def needs to not suck air there to run.
Fixin my vacuum lines is my main problem. My lines are butchered and I can't make heads or tails of what goes where now. I can't find an accurate diagram that shows where they all are. So I'm just screwed so far.
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Sep 15, 2011 | 12:38 PM
  #8  
Re: Backfire from a fuel injection. Need Help BAD!!!!!!!!!
On hood or or top of the frame up front.
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Sep 15, 2011 | 04:52 PM
  #9  
Re: Backfire from a fuel injection. Need Help BAD!!!!!!!!!
Quote: On hood or or top of the frame up front.
All my vacuum lines I have found so far are plugged. Literally every line the guy could find has been plugged I think.
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Sep 15, 2011 | 07:23 PM
  #10  
Re: Backfire from a fuel injection. Need Help BAD!!!!!!!!!
There is an underhood sticker that basically lays out what connects where in terms of the vacuum lines (EMISSIONS HOSE ROUTING sticker). If the engine is still backfiring with all of them plugged, first thing I would look at is the ignition timing (after having the module tested or replace it), firing order (1-6 in order, NOT the 90* V6's 1-6-5-4-3-2!), and then a compression test in each cylinder to test for valve float...

But, first, I'd get a Haynes manual or something and some tools to learn to work on your own car... Most guys nowadays are lost on anything that's pre-OBDII. And, if you must, get a new mechanic. That guy is a cheat and an idiot.
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Sep 15, 2011 | 08:48 PM
  #11  
Re: Backfire from a fuel injection. Need Help BAD!!!!!!!!!
Quote: There is an underhood sticker that basically lays out what connects where in terms of the vacuum lines (EMISSIONS HOSE ROUTING sticker). If the engine is still backfiring with all of them plugged, first thing I would look at is the ignition timing (after having the module tested or replace it), firing order (1-6 in order, NOT the 90* V6's 1-6-5-4-3-2!), and then a compression test in each cylinder to test for valve float...

But, first, I'd get a Haynes manual or something and some tools to learn to work on your own car... Most guys nowadays are lost on anything that's pre-OBDII. And, if you must, get a new mechanic. That guy is a cheat and an idiot.
The underhood sticker is missing, also I have had the car timed two different times and I have compression. I would find a new mechanic but when asked if they know anything about my motor they have no clue. I have gone to the GM dealership to see if they know something I don't but they want 90 dollars an hour, and I know more about it then they do. Ad I know my car I grew up working on the car and it was given to me at fourteen. Its just a severe problem that I don't know much about. Thank for the advice thought.
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Sep 15, 2011 | 08:54 PM
  #12  
Re: Backfire from a fuel injection. Need Help BAD!!!!!!!!!
usually a backfire threw the intake means the engine is running lean, or the timming is way advanced.


anychance u could get a video of this thing running?
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Sep 15, 2011 | 10:52 PM
  #13  
Re: Backfire from a fuel injection. Need Help BAD!!!!!!!!!
First off, I would be in the technician business if there was a job nearby, and knowing what I know, I don't trust anyone with my car, and never have. And, knowing that the guy you just got your car back from plugged every single vacuum hose to try to fix the engine (making things worse instead of better), I'd bet he lied to you about fixing the timing and the engine having compression. As project said, most of the time, it's either incorrect ignition timing or wrong fuel mixture, but can also be valve float or incorrect firing order that causes backfire. Okay, so the guy may not have lied, but he may have used the #2 plug to time the engine, since it's in the front on the driver's side, instead of the #1, which is on the other, and he may not have disconnected the set timing connector by the blower motor doing so. In which case, the timing is still wrong.

Plus, you don't know as much as you think you know. Crossfire fuel injection was NEVER used on ANY V6, to my knowledge, especially the 60* V6 you have under your hood. It says it right on top of the engine, MULTI-PORT FUEL INJECTION, MPFI or MFI, as it's more commonly known.

Get a timing light, compression gauge (probably best to borrow one if you can), multimeter, and a decent set of tools and start figuring out what's wrong before you just throw parts at it. And do double check the firing order... I'm sure that if I can make my engine run on only one bank of cylinders (oops!), you can get yours running nicely.
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Sep 15, 2011 | 11:17 PM
  #14  
Re: Backfire from a fuel injection. Need Help BAD!!!!!!!!!
Next time you see a car like yours in a parking lot ask the owner of it if you can take pictures of thier vacume lines I had a toyota that said refer to sticker , but there wasn't one 2 trucks worth of pictures ann everything was good. then make sure you don't have any leaks you need to unplug your computer pass side brown wire near the heater in the engine compartment to set your timing unplug it before you start the car. check your cap and roter make sure your condenser is good mine had the condensor wire creep loose and all hell broke loose it was trieing to fire on all 8 cyl. barely made it to the side of the road it was back fireing alittle for part of the day then let loose. Never take your car to that guy again my 16 year old would have had it running in a day. 9get a V8 next time I had an 87 2.8 l. they kind of suck the moters not made well)
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Sep 15, 2011 | 11:28 PM
  #15  
Re: Backfire from a fuel injection. Need Help BAD!!!!!!!!!
I forgot to mention that I've posted links and pics of my emissions hose sticker any number of times... Almost ought to make it a sticky or something...

bwb, we don't have ignition condensers...
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Sep 21, 2011 | 02:08 AM
  #16  
Re: Backfire from a fuel injection. Need Help BAD!!!!!!!!!
? Backfire from a fuel injection. Need Help BAD!!!!!!!!!-a1301865.jpg


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Sep 21, 2011 | 11:17 AM
  #17  
Re: Backfire from a fuel injection. Need Help BAD!!!!!!!!!
Don't know what that distributor is out of, but it's not out of a 60* V6 produced after about 1985... Our ignition modules have 8 pins, not 4, and the connections are at the base of the dizzy...

http://shop.advanceautoparts.com/web...1582588651____

This is a reman with a newer-style pickup coil assembly. I have one boxed and ready to go because I'm switching to distributorless ignition...
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Sep 21, 2011 | 11:23 AM
  #18  
Re: Backfire from a fuel injection. Need Help BAD!!!!!!!!!
The module in that dizzy is an 8 pin module. It looks like a SBC HEI, computer controlled dizzy.
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Sep 22, 2011 | 11:08 PM
  #19  
Re: Backfire from a fuel injection. Need Help BAD!!!!!!!!!
I found it on some parts site I have a 1985 305 HO tuneport mine has only 4 wires, and a condenser wired in like this one if the plug to it gets loose it tries to fire all over the place backfires through the intake and out of the exaust. I only had a problem with it once due to a bad conection at the distributer. (due to user error I didn't plug it in tight enough)
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