rough idle, rough run no power
#1
rough idle, rough run no power
Hey all,
Fixed the misfire issues with my '99 F350 V10, put new boots on, new fuel filter, new FPR, new O2 sensor,things were fine. Now I have a rough idle and a rough running, no power situation with no codes at all. I pulled the cat and put a straight pipe in to isolate it as an issue, no difference. Pull out the EGR system to isolate, no difference. What I DO have is this wierd kazoo/buzzing sound coming from the back of the manifold that you can only hear when you shut down. It is precisely like pressure equalizing somewhere...since it is coming from around the idle control, could that be the source of the noise and the running condition? I unplugged the MAF to isolate it, and suddenly the idle, while still rough, started hunting like a big vacuum leak, from about 900 to 1500. Plug it back in, no hunting, steady at about 900, but rough like all the injectors are running at 70%. I have also replaced most vacuum lines (one of the short little pieces on the evap canister was almost completely rotted), and I just had the manifold studs done and new gaskets are everywhere. And that buzzing...it sounds like a solenoid trying to close...like I said, kazoo, reed valve, similar sound...but I cannot isolate it. ANYONE ever have that?
I think I may have posted this elsewhere, and if I did, sorry for starting a new thread...I'll have to figure out how to consolidate. But I just fired it up and got this issue again after clearing it up. Just a bit frustrated, since I think it is simple but elusive.
Fixed the misfire issues with my '99 F350 V10, put new boots on, new fuel filter, new FPR, new O2 sensor,things were fine. Now I have a rough idle and a rough running, no power situation with no codes at all. I pulled the cat and put a straight pipe in to isolate it as an issue, no difference. Pull out the EGR system to isolate, no difference. What I DO have is this wierd kazoo/buzzing sound coming from the back of the manifold that you can only hear when you shut down. It is precisely like pressure equalizing somewhere...since it is coming from around the idle control, could that be the source of the noise and the running condition? I unplugged the MAF to isolate it, and suddenly the idle, while still rough, started hunting like a big vacuum leak, from about 900 to 1500. Plug it back in, no hunting, steady at about 900, but rough like all the injectors are running at 70%. I have also replaced most vacuum lines (one of the short little pieces on the evap canister was almost completely rotted), and I just had the manifold studs done and new gaskets are everywhere. And that buzzing...it sounds like a solenoid trying to close...like I said, kazoo, reed valve, similar sound...but I cannot isolate it. ANYONE ever have that?
I think I may have posted this elsewhere, and if I did, sorry for starting a new thread...I'll have to figure out how to consolidate. But I just fired it up and got this issue again after clearing it up. Just a bit frustrated, since I think it is simple but elusive.
#2
#3
Thanks, Krewat, for that info. I knew the booster was a check valve, had not even thought about isolating it. And thanks for verifying my suspicions about the IAC. I'm going to pull it and take a look at it. I am too familiar with the Bosch idle control valves in German cars- they are rotary valves and can be cleaned fairly effectively. I have heard that you can clean the Ford IAC...true?
I also ordered a new MAF just for good measure. Got a good deal on it, decided why not, cannot hurt. If it's not needed, I have a spare. And, just going to pull all the coils and plugs and check them, just be sure.
I also ordered a new MAF just for good measure. Got a good deal on it, decided why not, cannot hurt. If it's not needed, I have a spare. And, just going to pull all the coils and plugs and check them, just be sure.
#4
#5
Fuel pressure seems ok...30-32 at idle, 40 with vacuum disconnected. New FPR, new fuel filter, but pump is original to the chassis so '99, 174k. I figure I'll replace the pump in another year or so, but for now it all seems to be running steadily. I would prefer not to have to put a new one in, as I still have 35 gallons in the tank!
I'll likely replace the IAC if it doesn't look cleanable...not expensive anyway. Do that after I pull the plugs to see what is what in the cylinders.
New MAF here on Thursday, will see if that alters anything. The cat was a big plugged, so I put a straight pipe in to isolate it as the root problem, and will probably replace it for good measure. The truck has hauled and towed all its life, so I expected it, but I think maybe the misfire I solved did some dumping of raw fuel and shortened the cat's life.
Otherwise, just step by step.
Thanks for all the help an advice, now and future.
I'll likely replace the IAC if it doesn't look cleanable...not expensive anyway. Do that after I pull the plugs to see what is what in the cylinders.
New MAF here on Thursday, will see if that alters anything. The cat was a big plugged, so I put a straight pipe in to isolate it as the root problem, and will probably replace it for good measure. The truck has hauled and towed all its life, so I expected it, but I think maybe the misfire I solved did some dumping of raw fuel and shortened the cat's life.
Otherwise, just step by step.
Thanks for all the help an advice, now and future.
#6
SUCCESS!
So, I did a plug change. I don't want to offend anyone's ego, but it wasn't the problem I had anticipated, I think because I've been working on VWs and Porsches most of my life, and VW aircooled heads have 6 threads for the plugs at most. And as for the #5 plug, it's only a pain if you've never done plugs, valve adjustment and fuel injection pump adjustment on an old 911. That sucks, just a bit.
Anyway, I found 9 plugs were a bit rich, and cylinder 2 was too lean. Put new plugs in, adjusted the coil springs, tied down every injector connection, made sure I had a good seat on each plug, and put in a spanking new MAF. The result is a truck that purrs like a kitten.
So, thanks for everyone's help, now and for future issues!
So, I did a plug change. I don't want to offend anyone's ego, but it wasn't the problem I had anticipated, I think because I've been working on VWs and Porsches most of my life, and VW aircooled heads have 6 threads for the plugs at most. And as for the #5 plug, it's only a pain if you've never done plugs, valve adjustment and fuel injection pump adjustment on an old 911. That sucks, just a bit.
Anyway, I found 9 plugs were a bit rich, and cylinder 2 was too lean. Put new plugs in, adjusted the coil springs, tied down every injector connection, made sure I had a good seat on each plug, and put in a spanking new MAF. The result is a truck that purrs like a kitten.
So, thanks for everyone's help, now and for future issues!
#7
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#8
That's on the punch list...since that is also the bank I had the lean condition on, I'll just have to check the plugs at intervals. Don't mind pulling injectors to clean, no a bad job.
I'm putting a new cat in, so I still have the bypass pipe in, and it sets up a really unique resonance. It also has almost an exhaust brake effect when you let off the accelerator, at least more so than the engine has normally. Kinda handy.
Any suggestions for cats? I've used Magnaflow and Random Technology high flows in the past and like them, though Random doesn't make one for this truck. Being a welder helps, so I don't need direct fit. Also considering pulling the exhaust to the side of the bed, pax side.
Anyway, great to have it up and running, and to have some little things to keep me busy with it. Runs as well as it ever did. I think everyone should pull their coils and make sure the boots are in great shape, AND make sure the springs is fully seating on the plug...I'd had that issue on another deep well car before, and should have remembered.
I'm putting a new cat in, so I still have the bypass pipe in, and it sets up a really unique resonance. It also has almost an exhaust brake effect when you let off the accelerator, at least more so than the engine has normally. Kinda handy.
Any suggestions for cats? I've used Magnaflow and Random Technology high flows in the past and like them, though Random doesn't make one for this truck. Being a welder helps, so I don't need direct fit. Also considering pulling the exhaust to the side of the bed, pax side.
Anyway, great to have it up and running, and to have some little things to keep me busy with it. Runs as well as it ever did. I think everyone should pull their coils and make sure the boots are in great shape, AND make sure the springs is fully seating on the plug...I'd had that issue on another deep well car before, and should have remembered.
#9
Some diagnostic notes about this issue with the truck:
The buzzing I heard wasn't the IAC, it was the vacuum regulator for the EGR valve. I just put the EGR back in, because I was getting some detonation at part throttle under load, and once I did the buzzing went away. I figure the EGR's vacuum regulator was using the bleed vent because it had gone to max duty cycle and had no EGR to operate.
I have come to the conclusion that coils go bad far less often than it seems...I think if everyone changed the boots AND adjusted the springs so that they got solid contact with the plugs, most misfire issues would go away.
When I had the EGR out, I got the usual codes, until I put the DPFE back in, and simply looped some hose between both ports, in an attempt keep the PCM seeing the sensor, and fooling the sensor into thinking there was no pressure differential, hence the valve was closed. My result was no code relating to the DPFE. Other people may get a different result. I did get some detonation which has of course gone away with the EGR back in, and it's just not that big a pain to work around.
I've spend a couple of days and a bit of gas running w/o the EGR, and have noticed no real difference in fuel economy, and maybe a slight decrease. The cleaner bay and manifold are not, imo, worth the detonation or the efforts to get the PCM to work without it. I have not found an eliminator specific to my truck, and I am not willing to spend $300 plus bucks to reprogram the computer. If I am gonna spend that money it is going to be on a bigger trans cooler, or a kitty towards a Sun or Woods trans. Anyone know if the TorqShift would fit in the early 350, and be a good swap?
Keeping a close eye on bank 2 injectors and plugs to ID lean issues before they become a problem, but so far it just appears I had a bad connection.
Thanks again to everyone for help, on this thread and others I may have authored.
The buzzing I heard wasn't the IAC, it was the vacuum regulator for the EGR valve. I just put the EGR back in, because I was getting some detonation at part throttle under load, and once I did the buzzing went away. I figure the EGR's vacuum regulator was using the bleed vent because it had gone to max duty cycle and had no EGR to operate.
I have come to the conclusion that coils go bad far less often than it seems...I think if everyone changed the boots AND adjusted the springs so that they got solid contact with the plugs, most misfire issues would go away.
When I had the EGR out, I got the usual codes, until I put the DPFE back in, and simply looped some hose between both ports, in an attempt keep the PCM seeing the sensor, and fooling the sensor into thinking there was no pressure differential, hence the valve was closed. My result was no code relating to the DPFE. Other people may get a different result. I did get some detonation which has of course gone away with the EGR back in, and it's just not that big a pain to work around.
I've spend a couple of days and a bit of gas running w/o the EGR, and have noticed no real difference in fuel economy, and maybe a slight decrease. The cleaner bay and manifold are not, imo, worth the detonation or the efforts to get the PCM to work without it. I have not found an eliminator specific to my truck, and I am not willing to spend $300 plus bucks to reprogram the computer. If I am gonna spend that money it is going to be on a bigger trans cooler, or a kitty towards a Sun or Woods trans. Anyone know if the TorqShift would fit in the early 350, and be a good swap?
Keeping a close eye on bank 2 injectors and plugs to ID lean issues before they become a problem, but so far it just appears I had a bad connection.
Thanks again to everyone for help, on this thread and others I may have authored.
#10
A TS in where a 4R100 is almost impossible without an external aftermarket controller, and a manual-tranny PCM (or a reflash). Interesting note about the DPFE gotta remember that one.
The detonation without the EGR is about expected. Any vehicle that is supposed to have one, and it's not working, usually does the exact same thing.
As for the frequency of COP failures, I agree. Ford has a TSB out about testing them, because dealers' techs were apparently replacing WAY TOO MANY and Ford was finding most of them weren't bad at all. Something like 70% I think, were still good but were replaced under warranty.
The detonation without the EGR is about expected. Any vehicle that is supposed to have one, and it's not working, usually does the exact same thing.
As for the frequency of COP failures, I agree. Ford has a TSB out about testing them, because dealers' techs were apparently replacing WAY TOO MANY and Ford was finding most of them weren't bad at all. Something like 70% I think, were still good but were replaced under warranty.
#11
70% is a pretty big number...wonder where the good coils that were swapped out ended up...be nice to get some cheap to have on hand. I expect any mass produced electronic component to have a failure rate, but all the chatter over the years about coils failing en masse seemed a bit much.
I thought the DPEF trick was interesting as well. I wonder had I driven around a week or so if I would have seen a low flow code. Got one before I put the re-routed DPFE back in. Could be I didn't let it run like that long enough, or could be it simply did the trick. Anyway, I have the entire EGR system back in and in comparing mileage with and without, I have to give a slight edge to having the EGR system installed. But I attribute that specifically to the fact that my PCM is programed for an EGR...if I sourced one for a non-EGR truck, I guess I would see about the same mileage as I have now. I won't throw a party unless I see 20mpgs.
And thanks for the information about the trans swap. Seems to be less hassle and money to simply get a built unit. And mine is fine right now, so no need to spend money that doesn't need to be spent.
I thought the DPEF trick was interesting as well. I wonder had I driven around a week or so if I would have seen a low flow code. Got one before I put the re-routed DPFE back in. Could be I didn't let it run like that long enough, or could be it simply did the trick. Anyway, I have the entire EGR system back in and in comparing mileage with and without, I have to give a slight edge to having the EGR system installed. But I attribute that specifically to the fact that my PCM is programed for an EGR...if I sourced one for a non-EGR truck, I guess I would see about the same mileage as I have now. I won't throw a party unless I see 20mpgs.
And thanks for the information about the trans swap. Seems to be less hassle and money to simply get a built unit. And mine is fine right now, so no need to spend money that doesn't need to be spent.
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