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Discussion Starter · #1 ·
I recently picked up the rest of what was needed to drop to a 3.5 including a zzp pcm. Car started right away and got over 100 miles before running into an issue. Car felt like it jerked and threw a p0101 code. Car would also drop to 500 rpm when letting off gas and stall if I didn't keep on the gas. Boost gauge would show boost regardless of how much gas you gave and even at idle it would show boost. Replaced MAF sensor and had same issue same code.. Emailed zzp and they said its probably the MAP sensor and it could cause that same code and cause the wierd boost readings. Replaced MAP sensor and made it about 15 miles until it happened again. Car drives good gets up good but drops in rpm and wants to die. Boost gauge showing over half full at idle. Did find beginning of crack in t fitting at intake manifold leading to MAP sensor so I will replace that. Anything else I should take a look at before assuming its the PCM causing these issues? Thanks
 

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It's not the pcm. That's a solid-state thing, and your issue developed physically after the tune already performed normally.

Check over the vacuum fittings everywhere, and any other parts you've touched while doing work on it to.make.sure things are tightened, sealed, and clean.
 

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Discussion Starter · #3 ·
It's not the pcm. That's a solid-state thing, and your issue developed physically after the tune already performed normally.

Check over the vacuum fittings everywhere, and any other parts you've touched while doing work on it to.make.sure things are tightened, sealed, and clean.
All fittings look good minus the t I will replace. Took it off and it just broke in 3 pieces very easily. Hoping thats the issue but not sure where to look next if not fixed.
 

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Discussion Starter · #4 ·
Ok I am completely stumped with this car. Just replaced the vacuum line from map sensor to boost solenoid also replaced boost bypass valve at zzps guess of the issue. I no longer am getting the p0101 code and car no longer goes into a limp mode of sorts and wants to stall when letting off the gas.

Car runs and drives great until i would say it warms up and any sort of boost is made. It doesn't always do it right away or all the time. But you know there is an issue when you see boost levels rise at the slightest touch of the gas pedal even at freeway speeds with cruise control on. Once this happens and you come to a stop at idle there is a pretty noticeable miss that can be felt and heard in the exhaust.

Maf / map/ boost bypass valve and vacuum lines all replaced. Cleaned air filter. What could be causing this issue? Long term fuel trim at idle is at -12 before issue as I believe it's due to small exhaust leak. Once issue arises it's at -22. I'm stumped. All I can think of is if getting on the gas causes the issue could it be fuel issue? Fuel pressure regulator or bad injector. Or...Bad catalytic converter which is a 2.5 downpipe that's only like 3 years old?

Thanks for the help
 

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Those fuel trims indicate a rich condition, which is the opposite of what happens with leaks. I'd pull plugs and get a picture with them all together and label the paper/shop towel they're on.

Getting into some boost during cruise is normal, as the car is loaded down in high gear trying to maintain speed by adding some power. My GTP did it and my EcoBoost truck does it, pretty normal. It's just the general fueling condition that should be diagnosed and cleared up. Replacing parts that don't typically fail due to other new things you've introduced and not dialed in yet, isn't a good precedent to set for your wallet.
 

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Discussion Starter · #6 ·
Those fuel trims indicate a rich condition, which is the opposite of what happens with leaks. I'd pull plugs and get a picture with them all together and label the paper/shop towel they're on.

Getting into some boost during cruise is normal, as the car is loaded down in high gear trying to maintain speed by adding some power. My GTP did it and my EcoBoost truck does it, pretty normal. It's just the general fueling condition that should be diagnosed and cleared up. Replacing parts that don't typically fail due to other new things you've introduced and not dialed in yet, isn't a good precedent to set for your wallet.
Ok when I can and its now not snowing I'll do that. Car almost didn't want to start and almost died as it didn't want to speed up when given a decent amount of gas getting on the freeway this morning. Got to work and it died twice Stepping on gas to see what it would do. No codes.

The boost was an issue because it never did it on the car unless it started acting up. At one point it would idle in park showing more than half boost on display. Not too worried throwing a little money at car. It survived it front of my house we lost in the southern oregon wild fire. Figured the heat it went through may have done some harm to hoses and what not. Totaled out but bought it back
 

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Ya, glad you got thru the damage as best you could. I'd just keep giving things a once-over, and monitor all you can. Fuel pressure, compression, vac lines, wiring harnesses... As weather gets better, you'll be able to climb around it more, but whatever you can see from the top-side may shed some light as well.
 

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Discussion Starter · #8 ·
Ya, glad you got thru the damage as best you could. I'd just keep giving things a once-over, and monitor all you can. Fuel pressure, compression, vac lines, wiring harnesses... As weather gets better, you'll be able to climb around it more, but whatever you can see from the top-side may shed some light as well.
So I'm assuming if I'm running rich that's why the stalling when giving gas? What will I look for with plugs?
 

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One might be extra wet from a stuck-open injector, or something like that. However, if your car is thinking, based on higher boost/MAP readings, that it's flowing more air, then it's sending more fuel to compensate.

You may need to look for a way to recalibrate its base barometer setting prior to start-up. I would have to search for that one, but if you can the readings at key-on only, they may say something about it (not right near 100kPa, etc.). This one will take a few more tricks to figure out, but the car should be happy after it is.
 

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Discussion Starter · #10 ·
One might be extra wet from a stuck-open injector, or something like that. However, if your car is thinking, based on higher boost/MAP readings, that it's flowing more air, then it's sending more fuel to compensate.

You may need to look for a way to recalibrate its base barometer setting prior to start-up. I would have to search for that one, but if you can the readings at key-on only, they may say something about it (not right near 100kPa, etc.). This one will take a few more tricks to figure out, but the car should be happy after it is.
Thanks for your input. Once I have them all pulled what should gap be on all the plugs? I think they are autolite 604 if I remember correctly when I bought the 3.5 pulley and pcm from zzp.
 

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You're pretty safe going by whatever their standard recommendation is at that point (0.055-0.060"?), since that's a fairly common setup.
 

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Discussion Starter · #12 ·
Still having some of the same issues now that hot weather has fully kicked in. What I have noticed is map sensor readings at some point while driving begin to hit 90+ kpa to 130+ if floored. When this reading is high is when the boost gauge begins to act up. At idle it will show boost and regardless the amount of throttle the boost gauge goes up like watching the tach when revving. When both these symptoms are present something I would assume is triggered with the pcm and the car jerks really quick and now my short and long term fuel trims are in the high negatives. -25 short -40 long. If I let off the gas the rpms drop and will want to die. Coming to stop without staying on gas will make the car die. The only time I get a code is if I let it die and it's always a pending p0101 code.

I'm stumped. Things that have been replaced this year and no not all just because of this issue are....fuel filter, fuel pressure regulator, maf sensor - 3 different times 2 brands, maf sensor wiring harness,map sensor, entire vacuum line from map sensor to intake manifold to the bbv, pcm with a zzp one, plugs, wires, coils.

Could a bad boost solenoid cause these issues? Boost issue causing car to think its under load pcm reacts and cuts gas way back? Just not sure why the p0101 code each time when it's new and new connector. Maybe I need to have exhaust checked?

Pics are while it's acting up. Rpm is high as it's in 3rd about to get off freeway.

Thanks for any insight.
 

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Your tune is probably jacked up from not being initially set-up properly for your configuration, and/or some wiring work isn't right. Doing a bunch of swap-tronics has only cost you time and money.

A) eliminate that BBV solenoid, leave the lower port of the valve open, top connected to top of M90 tree, and end the MAP vac line at the fuel regulator.

B) figure out the settings on your pcm, and make sure you're not hamstringing it with any vacuum or wiring glitches. Think thru this process as something that's probably not fixed by buying a part, but by using the ones you have correctly.
 

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Discussion Starter · #14 ·
Not throwing parts at it. Most were done around the time I installed everything I got from zzp beginning of year when I dropped to a 3.5. Maf sensor was lifetime warranty so I used that as reason to exchange and then swap to a different brand.

I have no way of looking at the tune but I will do what you mentioned concerning the bbv solenoid. As for wiring and everything nothing has been messed with or looks bad. Car did survive a wildfire that melted parts of the body but I have found no melted wiring or damage under the hood. Thanks
 
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