Fordracer Posted May 15, 2009 Share Posted May 15, 2009 A friend of mine has a 1999 7.3 with 230,000 miles on it. It starts and runs fine until you drive a few blocks and then it starts acting like it is loading up and then it starts missing out. It has a code P1247. I ran a cylinder contribution test and 1,3, and 5 show up missing. On the buzz test number 3 has a soft buzz. The ICP goes up to 2500 when you rev the motor up to 3,000 rpm, that's as high as it will rev. It blows out white smoke and smells very rich when you do this. He pulled the valve cover and checked the connector and the oil flow out of the spill spouts and it looks fine. He changed the oil, IPR, ICP, and MAP sensor with known good parts that I use for testing and it makes no difference. The fuel pressure is 55 lbs under a load. The only trucks I have had with high ICP have been the IPR or bad oil. I'm leaning towards injectors but that is an expensive guess. Any suggestions? Quote Link to comment Share on other sites More sharing options...
eastendpowerstroke Posted May 16, 2009 Share Posted May 16, 2009 Do you have a known good IDM? Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted May 16, 2009 Share Posted May 16, 2009 I wouldn't disagree with your guess about injectors. What's your ICPV KOEO and at idle? What's the production date-is it an early or late '99? Does it have MFDES in scan data? If so, tell me what the numbers are at a hot idle. Does it have an OE air filter that says "Intercooler" on the top of it? That's bad. If the prod date is before 12-98 it might have the bad air cleaner and no MFDES. Fill the FF with Stanadyne Performance Formula or PM-17a and see if it runs better. If it does, it's either bad fuel or bad injectors. Did you take a fuel sample? Good Luck! Edit: I went back and re-read the original posts because it had been so long, and I typed MFDES when I meant to type Perdels on this reply. I'll correct it here in case anyone does a search so it doesn't mislead them. MFDES is available on all trucks to my knowledge, but Perdels are only 99.5 up 7.3s. MFDES is a great way to identify fuel starvation, a complete set of weak injectors, or a worn engine. Perdels are great for identifying a weak cyl that won't throw a CC code. Quote Link to comment Share on other sites More sharing options...
LARRY BRUDZYNSKI Posted May 16, 2009 Share Posted May 16, 2009 Possible fuel contamination????? Rusted/Delaminated tank???? Quote Link to comment Share on other sites More sharing options...
Shlep Posted May 16, 2009 Share Posted May 16, 2009 Now you say you have 55PSI but what kind of volume are you getting and have you done a restriction test? Quote Link to comment Share on other sites More sharing options...
Fordracer Posted May 17, 2009 Author Share Posted May 17, 2009 I'll be looking at the truck again on monday after work so I'll check the air filter, MFDES, and build date then. Will the air filter say intercooler on it or the air filter lid? What's bad about the ones that say intercooler on them? The ICP voltage koeo was .24 and I think it was around .8 at 550 psi. The fuel looked good and clean and I haven't run an inlet restriction test. I do have a test IDM I could try if it comes to that. Thanks for the sugestions. Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted May 17, 2009 Share Posted May 17, 2009 Will the air filter say intercooler on it or the air filter lid? What's bad about the ones that say intercooler on them? This is the early '99 air cleaner, which really sucked. It's easy to recognize beacause it says "Intercooled" on top of the lid. The reason it sucks is because it sucks from the fenderwell instead of the grill of the truck. What billows out of the fenderwells when you're driving down a dirt road? Many engines were dusted because of the early '99 air filters. The '99 model year stretched nearly two years, because there was no '98. Later in '99 production, they switched to a better designed (not well designed, just not quite as bad) system which drew its air from the grill area. This style is easily identified by the square snorkel next to the driver's battery. If it doesn't have the square tube next to the battery, you can almost bet on a dusted engine. Check the turbo inlet for wear marks on the impeller wheel. This is one of my biggest pet peeves with Ford- they f'd up the design of the '94 air cleaner, (which was recalled for a new lid and steel bolts, which still sucked, even after the recall) they f'd up the design of the '99 AC, (which was the short lived design shown above) they f'd up the design of the 99.5 AC (which had the element suck into the housing, eliminating it's ability to filter), they f'd up the design of the 7.3 E-van filter (both early and late, which were too small, plugged early, and sucked into the housing like the later F model filter), they f'd up the design of the 6.0 E-van filter (which by the grace of God, did seal to it's housing, but was horribly too small), they f'd up the design of the 2003 6.0 AC (in which the MAF housing is too thin, warps, and allows the terrific Power Core filter to not seal against the MAF housing) and I'm not really happy about the 6.4 AC (which seems too wimpy to seal perfectly, and dusted 6.4 engines have already been reported). Why can't they do something as easy as build an air cleaner that works? In all of the chassis I work on and teach on, nobody else has any AC design problems, and Ford has ALL of the bad AC designs. WTF? Why didn't they just put one battery under the truck like an E-van and put a full "real truck" air cleaner under the hood? The square design 7.3 filter was the correct size for a 4.6 Crown Vic naturally aspirated motor, not a 7.3 turbo motor that probably uses 3 times the volume of air. Have you ever compared MAF reading of a gas engine at idle versus a diesel engine at idle? Hey guys, a gas engine pulls about 4 GPS at idle, a diesel pulls about 30-35 GPS. Not to mention a gasser never reaches 100% volumetric efficiency, and a diesel regularly goes way past 100% under boost. Do you THINK we should put a bigger air filter on this truck? Ford released the "redesigned" Power Core retrofit for the Gen 2 7.3s that worked well, but it should have been a recall. I could talk a half hour about their poor air cleaner designs and have tons of pictures of all of the failures, but I'll shut up. OK Jim, soap box back to you...... Good Luck! Quote Link to comment Share on other sites More sharing options...
Fredsvt Posted May 17, 2009 Share Posted May 17, 2009 Hey Bruce Ford isn't the only one with Air Cleaner issues, look at the Duramax LLY's thermal feedback loop issue. At times of full load pulling, the CAC and rad dumps so much heat into the air cleaner, the CAC can't dissipate the extra heat load and it ends up overheating the engine. Take a look at this word document: http://members.cox.net/beekiller/GMC%20Light%20Duty/THERMAL%20FEEDBACK%20LOOPS%20IN%20TURBOCHARGER%20APPLICATIONS.doc Quote Link to comment Share on other sites More sharing options...
eastendpowerstroke Posted May 18, 2009 Share Posted May 18, 2009 OK Jim, soap box back to you...... Good Luck! <----- Bruce's soap box Quote Link to comment Share on other sites More sharing options...
Fordracer Posted May 19, 2009 Author Share Posted May 19, 2009 That's some interesting information on air filters Bruce. It would be very interesting to sit down with you and pick your brain for several hours. The truck does have the "intercooler" air filter and he says it does get ditry very quickly. The turbo fins are very slightly rounded off. It does have the MFDES pid and it is 25 at cold idle. I was warming it up to run another cylinder contribution test and by the time the EOT went over 150 degrees it slowly shut off. After it sat for 5 minutes it would start back up ruuning very rough and the MFDES was 55 and load was 85%. He works third shift so during the day I had him fill the filter housing with PM-17a and he said it made on difference. He also tried my test IDM and it ran the same. The fuel pump is very noisey and when I opened the drain valve with KOEO and fuel pump running fuel shot out of it under alot of pressure and volume. It acts just like a 6.0 when you get combustion in the fuel system and it slowly looses cylinders on the same bank while it warms up until it slowly dies but I haven't seen a 7.3 do this. Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted May 19, 2009 Share Posted May 19, 2009 That's some interesting information on air filters Bruce. It would be very interesting to sit down with you and pick your brain for several hours. I usually teach in KC at Vision every spring. The truck does have the "intercooler" air filter and he says it does get dirty very quickly. Ruh Roh. The turbo fins are very slightly rounded off. Not good. It does have the MFDES pid and it is 25 at cold idle. Really not good. This means it's struggling to stay alive, usually either from low fuel pressure or bad injectors. Think of MFDES as STFT in a gasser. I was warming it up to run another cylinder contribution test and by the time the EOT went over 150 degrees it slowly shut off. After it sat for 5 minutes it would start back up running very rough and the MFDES was 55 and load was 85%. FP is? He works third shift so during the day I had him fill the filter housing with PM-17a and he said it made on difference. Fuel sample looks like? He also tried my test IDM and it ran the same. The fuel pump is very noisy and when I opened the drain valve with KOEO and fuel pump running fuel shot out of it under a lot of pressure and volume. It acts just like a 6.0 when you get combustion in the fuel system and it slowly looses cylinders on the same bank while it warms up until it slowly dies but I haven't seen a 7.3 do this. Yes, a 7.3 will suffer from combustion gasses in the fuel system just like a 6.0 will. Here's an extreme case: Good Luck! Quote Link to comment Share on other sites More sharing options...
Fordracer Posted June 12, 2009 Author Share Posted June 12, 2009 I finally have an update. The guy finally coughed up some money to buy a couple injectors and he replaced the two that were missing and he says it runs alot better but not great. I told him he wasted his time just replacing two and that he needs to replace all of them. He said that there were three different brands of injectors on that side. Thanks for your help Bruce. I'll have to see what classes you teach at Vision and see if it's something I could use. I started looking at MFDES now that I know what to look for. Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted June 13, 2009 Share Posted June 13, 2009 I wouldn't disagree with your guess about injectors. What's your ICPV KOEO and at idle? What's the production date-is it an early or late '99? Does it have MFDES in scan data? If so, tell me what the numbers are at a hot idle. Does it have an OE air filter that says "Intercooler" on the top of it? That's bad. If the prod date is before 12-98 it might have the bad air cleaner and no MFDES. I went back and re-read the original posts because it had been so long, and I typed MFDES when I meant to type Perdels on this reply. I'll correct it here in case anyone does a search so it doesn't mislead them. MFDES is available on all trucks to my knowledge, but Perdels are only 99.5 up 7.3s. MFDES is a great way to identify fuel starvation, a complete set of weak injectors, or a worn engine. Perdels are great for identifying a weak cyl that won't throw a CC code. Glad you got it "fixed". Quote Link to comment Share on other sites More sharing options...
Fordracer Posted June 15, 2009 Author Share Posted June 15, 2009 Okay I might sound like an idiot but I have never heard of Perdels. Are you saying that it is a pid that is available on 99.5 and newer 7.3's. What should it read and what does it mean when it is out of spec high or low? Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted June 15, 2009 Share Posted June 15, 2009 Okay I might sound like an idiot but I have never heard of Perdels. Are you saying that it is a pid that is available on 99.5 and newer 7.3's. What should it read and what does it mean when it is out of spec high or low? The search engine is your friend, have you tried searching Perdels? We've covered this several times already. http://www.forddoctorsdts.com/forums/ubb...h=true#Post8687 Perdels are percent change in rotational velocity, used for detecting a misfire or weak cylinder. There are 8 Perdels in scan data, each assigned to a cylinder of the engine. They are a PID that is very helpful when you have a rough idle or rough engine that won't set a cylinder contribution code. They only exist on ’99.5 up 7.3 trucks and they only work after the engine is warmed up. They are not present on many cheaper aftermarket scan tools, only the better scan tools and OE tools like the NGS and IDS. Larger Perdel numbers indicate a poor contributor being detected. #8 cylinder almost always shows a higher number like 1.0-2.4% It takes about 3% to set a code during the Contribution Test. The PIDs are only active at a hot idle and go to 0 if the engine is revved up. The Good cyls are 0%. The BAD cyls are 1.5%-2.5% and higher (except #8). Bad cylinders an be either a bad injector or low compression. My experience is that it is USUALLY a bad injector unless it is a 99 truck, in which there were tons of dusted motors from bad air cleaners. #8: 1.0-2.0% is normal. #8 suffers from goofy problems caused by pressure waves or pulsations in the HP rail that the engineers really can't fix. Basically, the PCM is watching the CMP with a super fast stop watch and can tell when each cylinder fires, and the time it takes until the next cylinder fires. If this time is slightly too long, it indicates a sluggish cylinder. Perdels are the forerunner to the Cylinder Balance Test seen on all CAN vehicles. Perdels went away on the 6.0 'cause you didn't need them with the Balance test. IIRC, they were actually present but not enabled if you hooked a NGS to the 6.0. The newer gray cam sensor sometimes gives problems with Perdels that mimic injector or engine problems. If you see bad Perdels, try a different CMP and see if they change. Here's a page from my book showing a graphic of the NGS that would suggest a problem with cylinder #2: Good Luck! Quote Link to comment Share on other sites More sharing options...
Fordracer Posted June 15, 2009 Author Share Posted June 15, 2009 Thank you very much Bruce, very informative as usual. I hope I'm not waisting your time I didn't think of doing a search on it. Quote Link to comment Share on other sites More sharing options...
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