1987 928 1st start after 5 years today but...
07-28-2018, 09:18 PM
#1
Cruisin'
Thread Starter
Join Date: Jul 2018
Posts: 9
Likes: 0
Received 0 Likes
on
0 Posts
1987 928 1st start after 5 years today but...
Hello everyone, thanks for taking he time to read this. I recently bought a 928 that has been sitting several years. I flushed tank, installed new fuel pump and filter and cycled the pump with a power probe with the lines at the fuel at the rails off to push out old fuel.
Here is my issue. it will only run on the low pressure pump in the tank. If I power the pump next to the filter It will start to stall the car when pressure builds up. I can not get any throttle response either. Barely a touch will kill it. I have not got far as to test the fuel pump relay yet but regardless it will only idle at low rpm until the pressure from my cycling the pump drops and then it will die. I unplugged the Mass air flow sensor to see if it would run better but it doesn't. Most cars will at least run with it unplugged. Without a technical manual I am at a loss, Alldata is worthless on this car. I know its a fuel management issue. Spark is fine.
Any ideas? I am in the St louis Area
Here is my issue. it will only run on the low pressure pump in the tank. If I power the pump next to the filter It will start to stall the car when pressure builds up. I can not get any throttle response either. Barely a touch will kill it. I have not got far as to test the fuel pump relay yet but regardless it will only idle at low rpm until the pressure from my cycling the pump drops and then it will die. I unplugged the Mass air flow sensor to see if it would run better but it doesn't. Most cars will at least run with it unplugged. Without a technical manual I am at a loss, Alldata is worthless on this car. I know its a fuel management issue. Spark is fine.
Any ideas? I am in the St louis Area
07-28-2018, 09:31 PM
#2
Team Owner
I will bet you need to remove the intake and replace the idle control valve its frozen stuck
NOTE dont keep testing as possible computer damage could occur
I have an 88 that has been sitting for a few years and i got it to run at idle only ,
as soon as i touched the throttle it would die.
\ Once the intake came off it was obvious why it would only idle, the ICV was frozen. as well as all of the other electronic parts were also trash
NOTE you probably are due for an intake refresh,
call Roger he has a spread sheet with all of the parts you will need,
figure about 4 to 7 grand for all the parts you will need depending on what else you find,
if you cant do the work the price goes up to about triple that number.
good luck with your restoration.
NOTE dont keep testing as possible computer damage could occur
I have an 88 that has been sitting for a few years and i got it to run at idle only ,
as soon as i touched the throttle it would die.
\ Once the intake came off it was obvious why it would only idle, the ICV was frozen. as well as all of the other electronic parts were also trash
NOTE you probably are due for an intake refresh,
call Roger he has a spread sheet with all of the parts you will need,
figure about 4 to 7 grand for all the parts you will need depending on what else you find,
if you cant do the work the price goes up to about triple that number.
good luck with your restoration.
07-28-2018, 09:34 PM
#3
You need to check the fuel pressure. I had a similar problem and it turned out to be the fuel pressure regulator. The car would run on low pressure but as soon as the pressure built up it would overwhelm the tired, 29 y/o FPR and it would die.
Changed the FPR and the car drove like a dream.
Changed the FPR and the car drove like a dream.
07-28-2018, 09:48 PM
#5
Definitely get a pressure tester that will fit the fuel rail. It’s possible you have the leads swapped on your main pump.
07-29-2018, 12:09 AM
#6
Chronic Tool Dropper
Lifetime Rennlist
Member
Lifetime Rennlist
Member
The timing (schedule not ignition) is there to support LH failure as a possible cause. A very common failure mode is injectors cycling freely even before the starter is cranked. Your report of the engine running only on the in-tank pump points me towards the low available fuel flow compensating for the injection system problem.
Know also that LH failure is inevitable with the original controller. They fail in time with no obvious relationship to operating situation. It may be the reason the car was parked years ago, or it may as easily have faulted while it was parked. Regardless, it will need to be replaced even if it isn’t already failed.
Our supporting vendors and and others have the controllers available on an exchange basis. You can send yours in for testing if you can’t find another car to test test your controller.
Know also that LH failure is inevitable with the original controller. They fail in time with no obvious relationship to operating situation. It may be the reason the car was parked years ago, or it may as easily have faulted while it was parked. Regardless, it will need to be replaced even if it isn’t already failed.
Our supporting vendors and and others have the controllers available on an exchange basis. You can send yours in for testing if you can’t find another car to test test your controller.
Trending Topics
07-29-2018, 02:33 AM
#8
I worked with Roger about 2 years ago to put together a pretty comprehensive top end refresh parts list for my '84. It was 64 parts and less than $2K. Not sure what the specific differences for the 32V cars would be but Roger could tell you. If you are interested in the details PM me, I'd be happy to share the list with you.
07-29-2018, 09:08 AM
#9
Cruisin'
Thread Starter
Join Date: Jul 2018
Posts: 9
Likes: 0
Received 0 Likes
on
0 Posts
The timing (schedule not ignition) is there to support LH failure as a possible cause. A very common failure mode is injectors cycling freely even before the starter is cranked. Your report of the engine running only on the in-tank pump points me towards the low available fuel flow compensating for the injection system problem.
Know also that LH failure is inevitable with the original controller. They fail in time with no obvious relationship to operating situation. It may be the reason the car was parked years ago, or it may as easily have faulted while it was parked. Regardless, it will need to be replaced even if it isn’t already failed.
Our supporting vendors and and others have the controllers available on an exchange basis. You can send yours in for testing if you can’t find another car to test test your controller.
Know also that LH failure is inevitable with the original controller. They fail in time with no obvious relationship to operating situation. It may be the reason the car was parked years ago, or it may as easily have faulted while it was parked. Regardless, it will need to be replaced even if it isn’t already failed.
Our supporting vendors and and others have the controllers available on an exchange basis. You can send yours in for testing if you can’t find another car to test test your controller.
Dr Bob. the injectors do cycle BEFORE the car has started. I can hear them when key is on. What is the LH an abbreviation for?
07-29-2018, 09:51 AM
#10
Team Owner
Please post a picture of your engine
the LH is for the fuel injectors the EZK is for spark
the injectors cycling before you start indicated a computer failure
the LH is for the fuel injectors the EZK is for spark
the injectors cycling before you start indicated a computer failure
07-29-2018, 10:04 AM
#11
Cruisin'
Thread Starter
Join Date: Jul 2018
Posts: 9
Likes: 0
Received 0 Likes
on
0 Posts
How is posting a pic of my engine going to help? lol. After reading several articles I am pretty sure its a LH failure.
07-29-2018, 10:15 AM
#12
Rennlist Sponsor
Rennlist
Site Sponsor
Rennlist
Site Sponsor
Hello everyone, thanks for taking he time to read this. I recently bought a 928 that has been sitting several years. I flushed tank, installed new fuel pump and filter and cycled the pump with a power probe with the lines at the fuel at the rails off to push out old fuel.
Here is my issue. it will only run on the low pressure pump in the tank. If I power the pump next to the filter It will start to stall the car when pressure builds up. I can not get any throttle response either. Barely a touch will kill it. I have not got far as to test the fuel pump relay yet but regardless it will only idle at low rpm until the pressure from my cycling the pump drops and then it will die. I unplugged the Mass air flow sensor to see if it would run better but it doesn't. Most cars will at least run with it unplugged. Without a technical manual I am at a loss, Alldata is worthless on this car. I know its a fuel management issue. Spark is fine.
Any ideas? I am in the St louis Area
Here is my issue. it will only run on the low pressure pump in the tank. If I power the pump next to the filter It will start to stall the car when pressure builds up. I can not get any throttle response either. Barely a touch will kill it. I have not got far as to test the fuel pump relay yet but regardless it will only idle at low rpm until the pressure from my cycling the pump drops and then it will die. I unplugged the Mass air flow sensor to see if it would run better but it doesn't. Most cars will at least run with it unplugged. Without a technical manual I am at a loss, Alldata is worthless on this car. I know its a fuel management issue. Spark is fine.
Any ideas? I am in the St louis Area
One other thing to think about(beyond the other great suggestions) is the posibility of a failing (or failed) LH Computer. Your symptoms seem familiar to what I have experienced in the past.
If it is indeed something under the intake and you need to go in for an Intake RnR we have a comprehensive Interactive List of items needed for this on my website. You can go down the list, select what you need/want and it will automatically change the total. Same goes for Timing Belt Waterpump Kits. Those are there 24/7 to help you budget for your projects and sort out what you will most likely need..
Go to my website http://www.928gt.com (or just click our logo at the top/right of every 928 forum page where it says Sponsored by)then in the left menu select "928 Specialists Kits" and you will see the various Interactive Kits we have ready to help you with such projects.
Hope that helps,
Dave
__________________
David Roberts
2010 Jaguar XKR Coupe - 510HP Stock - Liquid Silver Metallic
928 Owners Club Co-Founder
Rennlist 928 Forum Main Sponsor
www.928gt.com
928 Specialists on Facebook - 928Specialists
Sharks in the Mountains on Facebook - 928SITM
David Roberts
2010 Jaguar XKR Coupe - 510HP Stock - Liquid Silver Metallic
928 Owners Club Co-Founder
Rennlist 928 Forum Main Sponsor
www.928gt.com
928 Specialists on Facebook - 928Specialists
Sharks in the Mountains on Facebook - 928SITM
07-29-2018, 10:22 AM
#13
Rennlist Sponsor
Rennlist
Site Sponsor
Rennlist
Site Sponsor
FYI, the LH computer is the Fuel Injector Computer and controls the Fuel Injectors.
Cheers,
Dave
07-29-2018, 08:08 PM
#14
Chronic Tool Dropper
Lifetime Rennlist
Member
Lifetime Rennlist
Member
LH controller is the fuel injection computer. Lives hidden by a carpet cover to the right of your passenger’s knees. Two controllers live there, both mounted on a bracket that bets an Allen drive to remove. Once the bolt is out, the bracket with both controllers slides directly to the rear.
Disconnect the the battery before working on this stuff. Don’t Open the Controller. The tabs have a limited number of flexes available and there’s nothing you’ll be able to do to to it yourself. Ship the box to one of our vendors and get it back in a week or so. Easy as it can be really.
Disconnect the the battery before working on this stuff. Don’t Open the Controller. The tabs have a limited number of flexes available and there’s nothing you’ll be able to do to to it yourself. Ship the box to one of our vendors and get it back in a week or so. Easy as it can be really.
07-29-2018, 10:58 PM
#15
Team Owner
OP you know what they say?..........A picture is worth a thousand words.
A picture of your engine will give additional info on the condition of your machine,
The more info you can provide ( like posting a few pictures) the more accurate the guesses will be to guide you to a solution.
A picture of your engine will give additional info on the condition of your machine,
The more info you can provide ( like posting a few pictures) the more accurate the guesses will be to guide you to a solution.