How do I test Coil Packs & Injectors

DonMaximo · Feb 9, 2010

Guys,

Having a problem with a stock 2001 GT SOHC exhibiting a "miss-like" symptom. It occurs at idle and during acceleration. Quite noticeable between 1500-2000 RPM upon acceleration.
It "seems" to go away with RPMs > 3000 and WOT- but this could be because it's drowned out by noise & power.

I've replaced plugs, air filter, COPs, and TPS. Vacuum is at 20-22" idling. I've applied MAF cleaner to the MAF. None of this helped or hindered.

My SCT X3 (#3015) device is not reporting any DTC's.

Kind of running out of the low hanging fruit considerations. So I want to next check the coil packs and injectors.

How can each of these 8 devices be tested ???

I have the capability to DataLog... so are there any suggestions in this area ???
(please be specific as there are a huge numbers of parameters which I can log).

Any help would be appreciated.

-D

GDawg · Feb 9, 2010

The injectors you test resistance. I'll have to find the numbers. The coil packs... I don't know.

1fun281 · Feb 9, 2010

I have been chasign this problem forever now, if you find out anything please let me know. Ive tried coil packs plugs maf, we even put a whole new intake thinking it was a bad intake manifold gasket, we checked and cleaned alot of the injectors, and now im looking into buying a fuel pressure gauge to check my fuel pressure, im going to change my fuel filter as well. me and my friend are believing i have one bad injector some where that may be dribling fuel, because im gettign a code saying fuel air metering, and the computer isnt adjusting to fuel trim. It also said that im running either too lean or too rich, i was thinking of changing the two upstream or before cat 02 sensors, because i believe adjusting fuel trim is there job.

DonMaximo · Feb 9, 2010

check your vacuum...

I've had the too rich/lean condition DTC, and after I fixed the vacuum leak and cleared the code... it never returned.

Another thing...and I may get flamed on this... If you're using a K&N filter, try a simple/stock paper filter from your regular parts store.
Doing this actually resulted in my stumbling problem diminishing at idle.

wmburns · Feb 9, 2010

1fun281, Consider ruling out an EGR problem. Disconnect and plug the vacuum line to the EGR valve. This may generate a new EGR related DTC, but its OK because its for testing. If the symptoms inprove, suspect an EGR problem.

Note: if the EGR valve itself is stuck partially open then disconnecting the vacuum line test will be inclusive. The other option is to monitor the DPFE looking for flow when there shouldn't be any.

IMO, this is not an ignition problem. If it were then it would not get better at high RPM.

To all others, the full DTC's are really needed.

The odds favor a vacuum leak. Obviously, it is not going to be a typical easy to find one (or you would have found it by now). Consider getting it smoke tested or get yourself a propane based leak detector. Amazon sells an afordable unit for the home mechanic. IMO, it is not a good idea to spray carb/choke/brake clean to look for leaks.

Donmaximo, the K&N being an oiled element, the oil can contaminate the MAF. So not completely surprising that removing it cleared up the MAF problem.

COramprat · Feb 10, 2010

http://www.stangnet.com/mustang-forums/781013-how-check-bad-cops-multimeter.html

01GTSTANGER · Feb 10, 2010

DonMaximo said:
Guys,

Having a problem with a stock 2001 GT SOHC exhibiting a "miss-like" symptom. It occurs at idle and during acceleration. Quite noticeable between 1500-2000 RPM upon acceleration.
It "seems" to go away with RPMs > 3000 and WOT- but this could be because it's drowned out by noise & power.

I've replaced plugs, air filter, COPs, and TPS. Vacuum is at 20-22" idling. I've applied MAF cleaner to the MAF. None of this helped or hindered.

My SCT X3 (#3015) device is not reporting any DTC's.

Kind of running out of the low hanging fruit considerations. So I want to next check the coil packs and injectors.

How can each of these 8 devices be tested ???

I have the capability to DataLog... so are there any suggestions in this area ???
(please be specific as there are a huge numbers of parameters which I can log).

Any help would be appreciated.

-D

Dude im seriously having the same problem currently....Now the car does not even want to turn on and if it does itsd very choppy and I have to keep my foot on the gas pedal to not allow it to turn off..Strange the car was running perfect and all of a sudden the idle is horrible had to get it towed home. If you figure something out please share your input, I to have changed my plugs, pulled codes (I get the same code of it running lean or rich), cleaned my MAF sensor and nothing..All my vaccuum lines look intact so im pretty confused? Thanks bro and I find anything I will be sure to let you know. Thanks

Midnight2V · Feb 11, 2010

01GTSTANGER, will your car start if you hold the gas down slightly? Your symptoms sound like classic IAC issues. You may only need to replace your IAC.

01GTSTANGER · Feb 13, 2010

Not anymore, it would at first but now its just dead??? This is what im thinking and please correct me if I'm wrong...As soon as you turn your key to the on position before you actually crank the car the fuel pump should turn on and create fuel pressure in the fuel rails correct? Which means I could go to the fuel rail open the valve cap and press the fuel valve and gas should come out correct? I tried this on my 89 fox and sure enough fuel leaks out as soon as I press the valve in.. Now this is what im thinking if I'm correct and fuel should come out when valve is pressed could my fuel pump be out?

wmburns · Feb 13, 2010

On the 1999-2004 PATS disables the fuel and spark. This causes a crank with no start. No fuel pressure would be expected.

On the 1996-1998, PATS disables the starter.

Sure would be a same to replace the fuel pump only to find out it was really a PATS issue. So what is the theft light doing?

Also, check the IFS in the trunk.

And yes, the fuel pump should run for a few seconds when ever the key is cycled on/off/on. If not, it will never start.

OBTW, would be nice to know what the full DTC codes are. But often, running rich/lean is a vacuum leak. Can be other things. Would be best to outline all of the symptoms as there are multiple causes.

01GTSTANGER · Feb 14, 2010

So I checked the DTC codes and I didn't get any, I've checked my fuses all looks good I have tried to hear if the fuel pump turns o. And when my buddy turns the key I hear nothing. Switch in the truck good... So you guys think my fuel pump went out? I have no fuel pressure in the rails with the key on??

Thanks

How do I test Coil Packs & Injectors

DonMaximo

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GDawg

1fun281

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DonMaximo

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wmburns

COramprat

...I can take it. I think.

01GTSTANGER

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Midnight2V

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01GTSTANGER

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wmburns

01GTSTANGER

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How do I test Coil Packs & Injectors

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