Weird pop

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Ostang351

New Member

Feb 16, 2004

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Feb 16, 2004

#1

• Feb 16, 2004

• #1

This is bugging me....seems to happed when the motor is cold, but every one in a while I'll get a quick pop from the right side of the motor when accelerating. I have installed new o2 sensors and a new mass air. I have a MAC cold air intake but I don't think that is causing it. I know I haven't given too much to work with but anyone know what would cause a pop (or backfire) from the right side of the motor? Thanks in advance.

 

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blk92stangg

New Member

Jan 30, 2004

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Hawaii

Feb 16, 2004

#2

• Feb 16, 2004

• #2

How old are your wires? Does it have the same sound as when you have your wires mixed up?

 

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Ostang351

New Member

Feb 16, 2004

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Feb 16, 2004

#3

• Feb 16, 2004

• #3

I bought the car used, but the wires are motorsport 9mm. It only does it once in a while. The guy that sold it to me said it was the cold air intake popping when it is cold out, but I think that is BS. I am thinking either a vacuum leak. I want to remove the smog soon....is that worth it?

 

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noslow5_0

New Member

Nov 7, 2003

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dallas tx.

Feb 17, 2004

#4

• Feb 17, 2004

• #4

if it is coming from the right side of the motor that could be an indication the motor is running lean, and backfiring through the throttle body.... just my .02!!!

 

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jerry beach

Founding Member

May 20, 2002

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Ocala,FL

Feb 17, 2004

#5

• Feb 17, 2004

• #5

What year is your stang? Or what kind of car is it? I've heard alot about the 88's having bad injectors. Mine had them, every now and then, especially when the motor was cold, I would get a pop through the intake. After I replaced my injectors with ford racing ones, it never has happened again. You need to pull the codes and do the cylinder balance test. After you read the last engine running code, rev the engine once, just make sure it goes up to 2500 or so. The puter will pull the injectors one at a time and record the rpm drop that each one causes. If there are any weak injectors, it will flash the # of those cylinders. If it detects weak ones, this is most likely the cause of your "lean pop". Here is how you can pull the codes, all you need is a test light if you dont have a check engine light in the car. Use the test light in place of the analoge volt meter.

 

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Ostang351

New Member

Feb 16, 2004

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Feb 17, 2004

#6

• Feb 17, 2004

• #6

Thanks for the reply...it is a 1990 5.0 5spd, cobra upper and lower, edlebrock aluminum heads, stock ignition, exhaust, cold air intake, pro m mass air, tb b303 with 1.72's. It only really does it when the engine is cold and will pop once or twice. I can tell it is going to happen because if I shift easy into second and give it a bit of gas, it will hesitate then pop, then pick up and it won't do it again. After it warms it is fine. The coolant gague isn't working...it is hooked up on he intake but the gauge doesn't work in the instrument cluster. Could the computer be seeing that? Maybe a vacuum leak? It idles fine with the B303 right around 800....no surging. I am stumped. I have a check engine light so how would I jump the test breaker? (where you put the test light in)????

 

giddyup306

Founding Member

Oct 22, 2002

3,041

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Feb 17, 2004

#7

• Feb 17, 2004

• #7

Ostang351 said:

The guy that sold it to me said it was the cold air intake popping when it is cold out, but I think that is BS. ?

Click to expand...

It could be. If you have too much air entering the engine it will act like it's overcarbed (although it's SEFI). What size tb do you have? Could also be a valve not seating properly or a lose timing chain as well. It could aslo be a vac leak. The only time I've seen the injectors be the cause of a popping sound is when people replace them and the o rings aren't sealed properly. This will cause a vac leak and the sounds your describing.

 

ashford

Member

Dec 19, 2003

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fargo ND

Feb 17, 2004

#8

• Feb 17, 2004

• #8

the gague and the computer have seperate sensors. check cooland level and check out the ect, ic could be telling the comp the engine is warm so is running lean.

 

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jerry beach

Founding Member

May 20, 2002

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Ocala,FL

Feb 17, 2004

#9

• Feb 17, 2004

• #9

The diagnostic connectors pictured are located behind the drivers side strut tower. Since you have a CE light, you will only need the jumper wire pictured, then read the flashes on you CE light. If one injector is not putting out enough fuel, the puter will read that as lean and put more fuel to all of them. Thats the purpose of the cylinder balance test, to make sure they are all equal. That was my fix anyway, may not be yours. Try pulling all the plugs and look for one or two that are different than the rest. Remember what cylinders they came from if you see something suspicious.

 

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Ostang351

New Member

Feb 16, 2004

33

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0

Feb 17, 2004

#10

• Feb 17, 2004

• #10

Thanks everyone for the replys.....I'll mess with it this weekend. I miss my carbureted motor....hehehe (much eaiser for me when I got the hang of it)

 

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88stangnut

New Member

Dec 25, 2003

155

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westfield ,mass

Feb 17, 2004

#11

• Feb 17, 2004

• #11

mine does that too, its a 88 with a 93 motor in it, when its idlein its popin out or mostly the drivers side tail pipe, i thought it was the mufflers doing it but its not you see barly any moisture out ot the drivers side and when i rev it up lets say 2500 you can hear a loud pop out from the back on deaccel, just wonderin if that is the same thing, i mean this baby pops like crazy, could equal lenght headers do that popin sound or no cats????