Author Topic: backfiring, popping (Read 4277 times)

zebo87 · « **on:** February 01, 2010, 03:34:15 PM »

ok so heres the problem. first if cold it takes at least twice to keep the car going after starting. once it can run on its own the problem really turns on. if i floor it, it bogs down insteda of revving up(also does this if im cruising). once its idling and im ready to go it sputters bad. i have to really baby it for about 5-10 minutes to get it to act normal. once its warm it does okay. it wont accelerate to its potential and i cant get it past 3500 rpm. so heres what i have. gt-40 engine. cobra intake, cai, 75mm maf(cal for 19lb inj) and 75mm tb, shortys, off-road h pipe, flowmaster 40s. what ive checked so far-maf, iac, vac leaks, timing, fuel filter, fuel pres reg, full tune up. im not sure where to go next. maybe fuel pump. im at a loss now. thanks in advance.

Soaring · « **Reply #1 on:** February 01, 2010, 04:49:46 PM »

I'm not too schooled with the 87's, but it sounds like you have either a fuel delivery problem when it's cold or what we old carb guys would say is that you have a choke problem not activating. How does that EFI restrict the cold air from getting into the fuel induction at startup? I would assume it would be the MAF or MAP, but not sure.

zebo87 · « **Reply #2 on:** February 01, 2010, 08:15:10 PM »

yeah i thought maf also but i put it in about 9 months ago and this problem started about 3 months ago or so. i pulled codes but its been so ling im not sure what they were. i guess i will run them ago.

rmodel65 · « **Reply #3 on:** February 02, 2010, 06:07:04 PM »

have you tried cleaning the maf??

zebo87 · « **Reply #4 on:** February 03, 2010, 01:57:06 PM »

i pulled codes and got 12-isc out of range, and 21-collant temp or coolant temp sensor out of range. my ques is would the cool temp sensor cause the backfiring. i actually havent cleaned the maf because it looked okay but i will spray it down.

zebo87 · « **Reply #5 on:** February 05, 2010, 05:33:06 PM »

i was wondering if a bad injector would cause the backfiring or bogging down when i try to get on it. what about the fuel pump. im pretty sure its a fuel delivery issue. just want to pinpoint it.

Soaring · « **Reply #6 on:** February 05, 2010, 07:14:29 PM »

Try getting a fuel pressure gauge and see if it is indeed the fuil pump. Fuel pumps are cheap and a quick fix if that indeed is the problem.

zebo87 · « **Reply #7 on:** February 05, 2010, 09:28:40 PM »

i have a pump already but its a 190 lph and i thought that if i went that much over stock that id need a better fuel press reg. i hate easter egging but i really dont want to change the pump unless i absolutely have. a couple of other notes if i didnt already mention them are that when cruising and i try to go wot it does nothing and bogs down. thats what making me lean toward fuel pump. the other weird thing is that twicw in the last 2 months when i shut the car off i can still hear the fuel pump. not sure if its the relay or pump itself.

Soaring · « **Reply #8 on:** February 05, 2010, 10:01:32 PM »

How old is the gas in the tank? Many times condensation will accumulate and cause those same problems. Just guessing here.
I had that same problem with my 65, so I drained out the old gas and filled the tank with fresh gas, and the problem was solved. Yeah, you don't want to go easter egg hunting, so you might want to take it to a Ford dealership and have them find out what the real problem is.

zebo87 · « **Reply #9 on:** February 06, 2010, 10:07:45 AM »

its not old gas because its my daily driver so i fill it up often.

zebo87 · « **Reply #10 on:** February 10, 2010, 03:49:39 PM »

well cleaning the maf did it. revs all the way up, no backfiring or popping anymore. it looked ok but i sprayed it down and that was all it took. easy fix. next is the ignition.

Soaring · « **Reply #11 on:** February 10, 2010, 04:02:09 PM »

I clean my MAF every 6 months or so whether it needs it or not. That's also about how often I clean my K&N air filter. So, while I'm in there anyway, I do both. Maintenance is a pretty important part of owning a Mustang, so try to set up a schedule to change the oil and filter, clean the MAF, etc. It will save you a lot of headaches later.
Anyway, glad you got her fixed. Now, go out and drive it like it was stolen.

zebo87 · « **Reply #12 on:** February 10, 2010, 04:20:42 PM »

yeah im getting ready to change the oil and replace the air filter and a schedule is in the works.

rmodel65 · « **Reply #13 on:** February 15, 2010, 10:52:27 PM »

Quote from: rabidwolverine on February 10, 2010, 03:49:39 PM

well cleaning the maf did it. revs all the way up, no backfiring or popping anymore. it looked ok but i sprayed it down and that was all it took. easy fix. next is the ignition.

who is the man

zebo87 · « **Reply #14 on:** February 16, 2010, 03:25:02 PM »

yeah youre the man. thx again.

Soaring · « **Reply #15 on:** February 16, 2010, 03:52:42 PM »

Rmodel65 is a pretty fart smeller........errr. Smart feller.

zebo87 · « **Reply #16 on:** February 16, 2010, 08:43:33 PM »

yeah part of the prob was my air filter. i started to notice a slight reoccurence of the same issue today. i bought a new filter and cleaned the maf again so that should do it. it wasnt popping or anything like that just not like it was right after i cleaned the maf last week. plus i have been driving through a lot of dusty areas lately due to all the stinkin construction.

Soaring · « **Reply #17 on:** February 16, 2010, 10:01:57 PM »

Glad you were able to solve the problem. I spend most of a day out of each 6 months or so doing maintenance on my Mustangs. That's just the nature of the beast. Which reminds me. I need to clean the K&N filter on the Mach tomorrow. Thanks for the reminder.

zebo87 · « **Reply #18 on:** February 17, 2010, 02:34:13 PM »

im think im gonna start doin that too. no prob. my last airfilter wasnt a k&n but i picked one up sonowi just have to clean it instead of replacing it.

Soaring · « **Reply #19 on:** February 17, 2010, 05:55:38 PM »

Yeah, the K&N will last you about a million miles if maintained properly. Be sure to get the recharger kit to clean it with. You just have to spray the filter and let it sit for awhile, then just use the garden hose to wash it. The K&N is made from cotton, not paper, so it will clean up nicely. When it turns pink again, it's clean.

Author Topic: backfiring, popping (Read 4277 times)

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