10 in vac, running rich, no boost
10-08-2014, 03:52 PM
#1
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10 in vac, running rich, no boost
New to the forum and looking for answers for a bad run ability problem on a 99 FM11, link system. I drove the car after several months of sitting and all seemed fine, Turbo spooled ran great for about 5 mins after warming up. Then a shudder, idles rough, running very rich, turbo won't spool, and only has 10in vac. After running a bit and looking for vac leaks I loaded up the spark plugs and ruined my coil pack. I replaced the coil pack spark plugs and wires, sent the injectors out to be flowed and even sent the turbo out to be checked. Cleaned the MAF also. I found out that the FM turbo actuator was frozen and have ordered a replacement. With the actuator rod removed I still have the problem, no matter where I move the flapper.
I have looked and plugged off vac lines to test and can't find a leak, compression is good. After reading many posts I am wondering about the BOV, it is the big FM. If the BOV was faulty would I lose vac? How would you test this. I have had the car for 10 years and the turbo was already added, I had to play with the link for some time to get it to run right, and it has run good ever since. Could the bov be leaking vac and causing all this. The car is 800 miles away and I will be returning to work on it and want to have everything I will need to repair, planning on first checking timing to make sure belt hasn't slipped, bring along a map, cam, crank sensor, vac testor, code reader but I sure could use some help and ideas.
I have looked and plugged off vac lines to test and can't find a leak, compression is good. After reading many posts I am wondering about the BOV, it is the big FM. If the BOV was faulty would I lose vac? How would you test this. I have had the car for 10 years and the turbo was already added, I had to play with the link for some time to get it to run right, and it has run good ever since. Could the bov be leaking vac and causing all this. The car is 800 miles away and I will be returning to work on it and want to have everything I will need to repair, planning on first checking timing to make sure belt hasn't slipped, bring along a map, cam, crank sensor, vac testor, code reader but I sure could use some help and ideas.
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10-09-2014, 08:11 PM
#3
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Take a piece of wood and smack your catalytic converter and listen if you hear any rattles. May be clogged. I had same symptoms, though it would get about 1psi of boost but didn't go anywhere fast.
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10-10-2014, 11:28 PM
#4
There are several problems. First, not many people here run Link.
Second, the descriptions you use are all f'ed up.
Is english your first language? I am going to presume not and try and help you even though "bad run ability problem" is beyond my expertise. Espeically on a link.
When you heard the shudder, what was happening? Was it idling? Were you in boost? What exactly was going on with the car the moment before the shudder?
How do you know it's running rich? Do you have an air fuel ratio gauge? Is it a wideband gauge? How do you know you are getting 10in vac? What is your normal vacuum at idle?
What do you mean by "I loaded up the spark plugs"?
You cleaned the MAF... How? With a solvent? Did you clean the connector or the MAF wires themselves?
I think you need to read this:
https://www.flyinmiata.com/support/i...ECU_tuning.pdf
Page 6:
My bet is that the hose from the intake manifold to the LINK has somehow been broken or disconnected.
Second, the descriptions you use are all f'ed up.
Is english your first language? I am going to presume not and try and help you even though "bad run ability problem" is beyond my expertise. Espeically on a link.
When you heard the shudder, what was happening? Was it idling? Were you in boost? What exactly was going on with the car the moment before the shudder?
How do you know it's running rich? Do you have an air fuel ratio gauge? Is it a wideband gauge? How do you know you are getting 10in vac? What is your normal vacuum at idle?
What do you mean by "I loaded up the spark plugs"?
You cleaned the MAF... How? With a solvent? Did you clean the connector or the MAF wires themselves?
I think you need to read this:
https://www.flyinmiata.com/support/i...ECU_tuning.pdf
Page 6:
"Failure to see vacuum will make the fuelling pig rich, while failure to
see boost will cause the engine to blow up."
see boost will cause the engine to blow up."
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10-10-2014, 11:31 PM
#5
Actually if you have a 99 that might not be the correct document. Check here though:
Flyin' Miata : Instructions : ECUs
Flyin' Miata : Instructions : ECUs
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10-10-2014, 11:56 PM
#6
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I had a little something like this. Ever blow a boost hose off? I chased **** for 3 hour before I realized the boost hose came off the turbo. I couldn't really see it until I stared pushing/pulling on ****.
Idled poorly. Pig rich which didn't make sense at first. Then I was listening and sounded like the turbo was spooling at idle.
My theory is that the leak was just enough the ECU stared adding fuel. This "extra fuel" was not needed and therefore was burning in the exhaust; in-turn spooling the turbo slightly. This sucked even more air in thought the turbo (more importantly the MAF) dumping even more fuel.
It idled like **** and pig rich 10:1 or so. A vacuum leak post throttle body with a MAF = lean run. That's what had me. I didn't really ever think about it the "vacuum" leak was pre-TB on a turbo car. The engine isn't actually getting that extra air, but the MAF thinks it is. But it is getting the extra fuel it "thinks" it needs. 02 sensor doesn't have enough control to make it that rich.
What is your A/F at idle? What are your g/s at idle? If rich and too much air flow, go looking for a boost leak.
Idled poorly. Pig rich which didn't make sense at first. Then I was listening and sounded like the turbo was spooling at idle.
My theory is that the leak was just enough the ECU stared adding fuel. This "extra fuel" was not needed and therefore was burning in the exhaust; in-turn spooling the turbo slightly. This sucked even more air in thought the turbo (more importantly the MAF) dumping even more fuel.
It idled like **** and pig rich 10:1 or so. A vacuum leak post throttle body with a MAF = lean run. That's what had me. I didn't really ever think about it the "vacuum" leak was pre-TB on a turbo car. The engine isn't actually getting that extra air, but the MAF thinks it is. But it is getting the extra fuel it "thinks" it needs. 02 sensor doesn't have enough control to make it that rich.
What is your A/F at idle? What are your g/s at idle? If rich and too much air flow, go looking for a boost leak.
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10-11-2014, 02:45 PM
#7
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I thought my English was pretty good for a Nebraska Boy. I am not a tech just a 60 year old shade tree guy.
By loading up the plugs (old school term) I mean they are fouling out from too much fuel.
I am reading the 10in at the boost gauge and it used to read around 18 at idle, I believe. I had replaced the hose leading to both the Link and boost gauge with silicone hose when I got it and I have removed every section of it and made sure I did not have a leak. I shot throttle cleaner around the injectors, and any place I could imagine a vac leak including the link and boost gauge.
I know it is running rich as the Lamba shows 9 at 800 rpm and about 12 at 2000. The idle fluctuates from about 400-800 and the exhaust will burn your eyes.
I cleaned the MAF,and both sides of the connectors with CRC MAF cleaner, also any other connection I have had off gets a shot of this solvent.
When the problem developed the car had not been started or driven for a couple of months. I use a battery maintainer. I warmed the engine and took it out. I was in 3rd gear going up a hill and added gas to kick the turbo in and then heard the shutter. The car would run under load but miss at constant speed and die if I lifted the throttle. Max boost was set at 12, but that was in NE at 2000 ft elevation and MI is 400ft at the lake. I can't hear the turbo and get no boost at the gauge.
I have replaced the coil pack, plugs and wires as number 1 wire had very high resistance. I pulled the 02 and it was also sooty. Fuel pump pressure was checked and the fuel filter replaced. All gas removed and replaced with 91 octane non ethanol. I sent the turbo off to Hudson Turbo and it checked good. I sent the injectors off and had them flowed and checked, cleaned and flowed.
The car is at my vacation home in Upper Michigan and my tools are here in Nebraska so I am trying to gather as much info as possible before returning to try to repair. I will then take it to FM and update to hydra, they also suggested a couple hours of dyno tuning which I will spring for. I will have them put the AEC wide band and replace my Lamba.
I have been reading as many posts as I can find trying to gather ideas. From what I have read, I have been looking in the wrong area, I need to check all of the turbo connections and piping for leaks, cracks and the blow off valve to make sure it isn't frozen.
I have been reading the tuning manual, but until the underlying problem is repaired all the tuning in the world won't help. My understanding is that the piggyback link really does nothing or very little at idle and normal driving.
Hopefully this clears up my poor English. Any help would be appreciated and respectably responded to.
Scott
By loading up the plugs (old school term) I mean they are fouling out from too much fuel.
I am reading the 10in at the boost gauge and it used to read around 18 at idle, I believe. I had replaced the hose leading to both the Link and boost gauge with silicone hose when I got it and I have removed every section of it and made sure I did not have a leak. I shot throttle cleaner around the injectors, and any place I could imagine a vac leak including the link and boost gauge.
I know it is running rich as the Lamba shows 9 at 800 rpm and about 12 at 2000. The idle fluctuates from about 400-800 and the exhaust will burn your eyes.
I cleaned the MAF,and both sides of the connectors with CRC MAF cleaner, also any other connection I have had off gets a shot of this solvent.
When the problem developed the car had not been started or driven for a couple of months. I use a battery maintainer. I warmed the engine and took it out. I was in 3rd gear going up a hill and added gas to kick the turbo in and then heard the shutter. The car would run under load but miss at constant speed and die if I lifted the throttle. Max boost was set at 12, but that was in NE at 2000 ft elevation and MI is 400ft at the lake. I can't hear the turbo and get no boost at the gauge.
I have replaced the coil pack, plugs and wires as number 1 wire had very high resistance. I pulled the 02 and it was also sooty. Fuel pump pressure was checked and the fuel filter replaced. All gas removed and replaced with 91 octane non ethanol. I sent the turbo off to Hudson Turbo and it checked good. I sent the injectors off and had them flowed and checked, cleaned and flowed.
The car is at my vacation home in Upper Michigan and my tools are here in Nebraska so I am trying to gather as much info as possible before returning to try to repair. I will then take it to FM and update to hydra, they also suggested a couple hours of dyno tuning which I will spring for. I will have them put the AEC wide band and replace my Lamba.
I have been reading as many posts as I can find trying to gather ideas. From what I have read, I have been looking in the wrong area, I need to check all of the turbo connections and piping for leaks, cracks and the blow off valve to make sure it isn't frozen.
I have been reading the tuning manual, but until the underlying problem is repaired all the tuning in the world won't help. My understanding is that the piggyback link really does nothing or very little at idle and normal driving.
Hopefully this clears up my poor English. Any help would be appreciated and respectably responded to.
Scott
Last edited by scooterj; 10-11-2014 at 02:59 PM.
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10-11-2014, 02:55 PM
#8
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Just for clarity, I have not run the car since cleaning the Maf and air temp sensor. I sprayed the bi-metal strips and the outside connectors. I did not run it afterward as I cleaned my KN air filter and wanted to let it dry completely before re oiling.
Thanks again for all the suggestions
Scott
Thanks again for all the suggestions
Scott
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10-11-2014, 03:19 PM
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I'm not saying a leak past your t-body. I saying between the t-body and turbo. If there is a leak there, you will have no boost. Mine idled at 10:1. Made no boost because it was all leaking out the blown hose.
Some of the symptoms you described are just like mine. Chech every hose between your turbo and throttle body.
Some of the symptoms you described are just like mine. Chech every hose between your turbo and throttle body.
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10-11-2014, 03:37 PM
#12
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Also, are you running stock injectors?
Is your fuel control a piggy back unit runing with the stock ECU?
If yes to both of those things, unplug the piggy back unit ( take it out of the system). If the problem still exists, you have ruled out the electronics.
Are you running electronic boost control? If not, the reason for no boost is mechanical, not electrical.
Is your fuel control a piggy back unit runing with the stock ECU?
If yes to both of those things, unplug the piggy back unit ( take it out of the system). If the problem still exists, you have ruled out the electronics.
Are you running electronic boost control? If not, the reason for no boost is mechanical, not electrical.
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10-11-2014, 09:07 PM
#14
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Thanks for the ideas, I think the possibility of a leak before the TB is valid and the most promising. I will check the piping, hoses and clamps and the IC for leaks.
I'm just trying to gather ideas before my next trip up north and hopefully can drive back to FM and have them update the system. The stock injectors are used but the intake has four additional injectors on a fuel rail. The system does have an electronic boost controller controlled by the link. I don't think I can simply disconnect the Piggy back link as wires were spliced to send info to the link and modify signals to fool the ECM. Also I don't think I have a true a wide band just a 4wire and Lamba gauge. I could be wrong here.
I have been in the automotive business since I was 15 years old but my idea of tuning is in the era of adjusting valve clearances, changing distributor springs and acel pump cams. Having said that I have sat in many clinics, trainings, and spent most of my life in automotive shops as a NAPA Auto parts store owner. So don't give up on me I do understand enough to dig and get answers. I bought the car 10yrs ago as my machine shop was building Honda motors (by request) for kids who were reading magazines and thinking they could build a motor and add a big turbo with no electronics and have it live with no fuel mapping or timing retard under boost. I demonstrated a stock motor with a turbo could live and not cook itself, but bolting on a turbo without mods to fuel management and timing would just fry the motor. After getting the car I discovered it was a gas and have enjoyed it ever since. I just want to get it back in shape and running right.
Thanks for your help and understanding
I'm just trying to gather ideas before my next trip up north and hopefully can drive back to FM and have them update the system. The stock injectors are used but the intake has four additional injectors on a fuel rail. The system does have an electronic boost controller controlled by the link. I don't think I can simply disconnect the Piggy back link as wires were spliced to send info to the link and modify signals to fool the ECM. Also I don't think I have a true a wide band just a 4wire and Lamba gauge. I could be wrong here.
I have been in the automotive business since I was 15 years old but my idea of tuning is in the era of adjusting valve clearances, changing distributor springs and acel pump cams. Having said that I have sat in many clinics, trainings, and spent most of my life in automotive shops as a NAPA Auto parts store owner. So don't give up on me I do understand enough to dig and get answers. I bought the car 10yrs ago as my machine shop was building Honda motors (by request) for kids who were reading magazines and thinking they could build a motor and add a big turbo with no electronics and have it live with no fuel mapping or timing retard under boost. I demonstrated a stock motor with a turbo could live and not cook itself, but bolting on a turbo without mods to fuel management and timing would just fry the motor. After getting the car I discovered it was a gas and have enjoyed it ever since. I just want to get it back in shape and running right.
Thanks for your help and understanding
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10-11-2014, 10:09 PM
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No one has picked up on this yet... It doesn't solve your rough running and VAC problems, but just to be clear you removed the wastegate actuator? So nothing is controlling the internal wastegate flapper right now???? Of course you wont get boost if nothing is keeping the flapper closed...
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10-24-2014, 01:06 PM
#17
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BOV Valve
I just got back to work on the car. I took the BOV off and the piston is free and can be manually opened, however when I put the vac pump to it I can only get 10" vac and it won't hold vac. I can only get the 10" by pumping like crazy. The valve won't open with the pump.
I assume this isn't right and may be part of my problem.
Any thoughts?
I am going to put it back together and plug off the vac line to the BOV and see what I get for vac. I looked at all of the IC piping and connections and all seem tight and sound so I don't think I have any leaks before the TB.
I assume this isn't right and may be part of my problem.
Any thoughts?
I am going to put it back together and plug off the vac line to the BOV and see what I get for vac. I looked at all of the IC piping and connections and all seem tight and sound so I don't think I have any leaks before the TB.
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