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Need Help Low Boost Slow Throttle
Hey Guys, new to the forum thanks in advance for your help. I’ve got an 01 F350 7.3. I’ve been doing some modifications on for about a year. S&B intake, 5” MBRP exhaust, TS Chip, TS informant Riff Raff intercooler boots. I did not buy this truck to race just pull a heavy boat and wanted max mpg and performance. I’m seeing a hesitation in throttle response from a stop and boost on the INFORMANT 6 will max around 13psi. Truck runs and cranks ok but when starting from a stop seems to be a delay in acceleration. I’ve also got a little bit of turbo fart just before going into overdrive in certain conditions. Ever since installing S&B I’ve been hearing whooshing whenever truck shifts, I figured it was normal and I was hearing the turbo spooling down. But I hear the fart or intermittent sound when accelerating under load sometimes. I’ve checked for leaks and replaced intercooler boots 6000miles ago, they are still clean. Cleaned EPB tube and sensor, unplugged sensor and ran No difference. Checked hoses red green and Map Sensor hose. Checked voltage at Map Sensor with switch on. Read 1.5 volts. Codes I’ve seen are P0238, P1248, and P1211. Questions Do I need a Map Sensor Block with the TS chip Informant, is that why I’m only seeing 13psi through the OBDI port? Is it possible the wastegate could be a problem? Could the map sensor be bad even though it’s reading 1.5 volts with switch on engine off? How concerned should I be with the turbo fart happening every now and then? What could be the cause of the delayed throttle response? Thanks in advance for all your Help. |
Can anybody see the above post? I’m new to the site didn’t know if I was missing something. Thanks |
Yes, it is coming through just fine. an't really help much with your issue(s) though.
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What exactly do you mean by "turbo fart"? Are possibly referring to turbo surge? I had surge issues with my stock turbo and a chip installed.
It is possible that the wastegate is not holding and beginning to open early, which restricts your boost. Can you hook your boost leak tester to it and see how much pressure it will hold before it begins to open? You say you checked for boost leaks and replaced CAC boots. What about intake tubes at the plenum? Up pipes? Both common boost leak areas. |
I will recheck for leaks again. I’m pretty sure I’m starting to hear more hissing when accelerating than before. But it sounds like it’s coming from the back of the turbo. What I’m calling a turbo fart is when it sounds sorta like sharp quick bursts of air escaping when accelerating. It’s gradually getting more frequent. I pulled boat today with good hills, Boost stopped every time at 13 psi. Thanks for advice |
You need to do a boost check to look for leaks
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I have a S&B and you are hearing what is commonly called a turbo "bark". This happens when you're in the throttle and building up significant boost, then drop the load (like letting the throttle up for a shift). The official term for the noise is a turbo stall... perfectly normal.
P1211 tells me you have a hot tune - or an old code that hadn't cleared yet. Do you have a specific tune that sets the P1211 after it has been cleared? You can do a search here on this forums for the following terms: Boost leak detector, red line mod, and 7 turn mod. |
Originally Posted by Tugly
(Post 17797496)
I have a S&B and you are hearing what is commonly called a turbo "bark". This happens when you're in the throttle and building up significant boost, then drop the load (like letting the throttle up for a shift). The official term for the noise is a turbo stall... perfectly normal.
P1211 tells me you have a hot tune - or an old code that hadn't cleared yet. Do you have a specific tune that sets the P1211 after it has been cleared? You can do a search here on this forums for the following terms: Boost leak detector, red line mod, and 7 turn mod. I’m starting to consider the MAP sensor, even though the voltage was correct at 1.5v with switch on engine off. I’m running an TS chip with an Informant 6, Boost dead heads at 13psi from 50 horse tune to 140hp tune. On stock truck feels really weak pulling boat, makes very little boost Maybe 8 psi. Throttle response from stop is slow regardless of stock or hot tune. i really think the EBP is functioning as it should but is there a way to check and make sure? What will unplugging it do? Any help appreciated This thing is whooping me!! |
I found your P1211 - the 140 HP tune. That would ask for fuel and HP that doesn't exist with our stock configuration. Keep your tunes below 70 HP and you'll see better results on the gauges and the stopwatch. The seat-of-the-pants-O-meter lies like the overhead economy meter.
No mention of red line mod or the 7-turn mod in your last post. |
Originally Posted by Tugly
(Post 17799860)
I found your P1211 - the 140 HP tune. That would ask for fuel and HP that doesn't exist with our stock configuration. Keep your tunes below 70 HP and you'll see better results on the gauges and the stopwatch. The seat-pants-O-meter lies like the overhead economy meter.
No mention of red line mod or the 7-turn mod in your last post. There is definitely a problem regardless of tune. I’ve driven two other trucks with exact same setup down to same guage and exhaust. Both of them feel a lot better with throttle response and building close to 20lbs of boost stock on Informant 6. |
With stock injectors, you should be seeing 24lbs of boost with tunes. What about exhaust leaks between from the manifolds to the turbo?
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Originally Posted by CampSpringsJohn
(Post 17799936)
With stock injectors, you should be seeing 24lbs of boost with tunes. What about exhaust leaks between from the manifolds to the turbo?
Maybe I’m missing them. Im going to disconnect waste gate and try to wire shut and see if it makes a difference. Also is there a way to check EBP sensor without buying a new one? Seems to work when cold then back to normal but I want to be sure? My Dad is an old school diesel mechanic that doesn’t know a lot about modern setups, but he keeps saying since it works some as rpms go up it could have something to do with VGT in the turbo or wastegate stuck open. Truck did sit four about 4 months before I bought Completely out of fuel. Thanks everyone for your help. |
For up pipes, you can check for soot around the firewall where the up pipes go into the collector. This would jive with you saying the hissing seems to come from the back of the turbo.
For manifolds, you could visually inspect them to see if any holes, oxidation, etc. I'm sure there is a better way, I just don't know what it is. The 7.3 does not have a VGT turbo, so it will not be that issue for sure. The wastegate very well could be stuck open, or weak, or just needs tightening. |
Originally Posted by mcnance865
(Post 17800825)
For up pipes, you can check for soot around the firewall where the up pipes go into the collector. This would jive with you saying the hissing seems to come from the back of the turbo.
For manifolds, you could visually inspect them to see if any holes, oxidation, etc. I'm sure there is a better way, I just don't know what it is. The 7.3 does not have a VGT turbo, so it will not be that issue for sure. The wastegate very well could be stuck open, or weak, or just needs tightening. |
Originally Posted by Ricky Bobbie
(Post 17801386)
I went over up pipes and manifolds No soot whatsoever Looks perfect. I took actuator off wastegate, it was I took the truck for a test drive. Same results as before on the 75hp tune Max Boost was 14psi Got some turbo bark when in throttle during acceleration. Boost readings are from the TC Informant 6 which reads through the OBDI Kicker is I put the truck on stock and the Informant 6 read 21psi of Boost but truck still felt weak. Why would I get more boost from stock? Truck has a lot more power with 75hp tune but only builds 13 or 14psi. Also I noticed a lot of grease or or oil on the EBP rod under the exhaust side of the turbo. Pedestal leak? Is that normal? Thanks again for any help. |
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