Engine dies on highway
Thread Starter
Heel & Toe
Joined: Sep 2011
Posts: 16
Likes: 0
From: Chanhassen MN
Engine dies on highway
Hi Guys,
I hope someone has some advice... I have a 1991 stock L98. 78,000 miles. New injectors from FIC. New fuel filter. On the highway, 65+, stalled out. Waited 10 min, started right up, ran perfect. Drove another 80 miles, on the off ramp, stalled again, couldn't start it for 15 min, then ran perfect again.
Fuel pump? Any advice?
Thanks!
I hope someone has some advice... I have a 1991 stock L98. 78,000 miles. New injectors from FIC. New fuel filter. On the highway, 65+, stalled out. Waited 10 min, started right up, ran perfect. Drove another 80 miles, on the off ramp, stalled again, couldn't start it for 15 min, then ran perfect again.
Fuel pump? Any advice?
Thanks!
Safety Car
Joined: Aug 2002
Posts: 3,842
Likes: 230
From: SANTA CRUZ CA
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
I have advice for you. When the symptom occurs, what's missing; spark or fuel?
Until you narrow that much down (at least) we're WAG'ing, just like you. It could be a fuel pump...it could be a ICM...we can only guess at this point.
Until you narrow that much down (at least) we're WAG'ing, just like you. It could be a fuel pump...it could be a ICM...we can only guess at this point.
Burning Brakes
Joined: Mar 2010
Posts: 1,094
Likes: 68
From: Providence RI
Any hesitation/missing before it craps out?
How does it run when it's actually running? Full rpm range and full power?
I've had a few issues with my 91 where it would die, run the next day, etc.
Once was the coil, once was the icm, once was the pick-up coil, once was a plug wire falling off, once was a distributor gear stripping (modded engine), etc.
Any trouble codes/ses light when it dies? When it goes to restart, will it crank but not fire? Like the guys above said...need to know if its fuel/spark. Get a fuel pressure gauge and start with that, it's the easiest to check.
How many miles on the car since you've owned it? Do you know the maintenance history?
Mike
How does it run when it's actually running? Full rpm range and full power?
I've had a few issues with my 91 where it would die, run the next day, etc.
Once was the coil, once was the icm, once was the pick-up coil, once was a plug wire falling off, once was a distributor gear stripping (modded engine), etc.
Any trouble codes/ses light when it dies? When it goes to restart, will it crank but not fire? Like the guys above said...need to know if its fuel/spark. Get a fuel pressure gauge and start with that, it's the easiest to check.
How many miles on the car since you've owned it? Do you know the maintenance history?
Mike
Thread Starter
Heel & Toe
Joined: Sep 2011
Posts: 16
Likes: 0
From: Chanhassen MN
Thread Starter
Heel & Toe
Joined: Sep 2011
Posts: 16
Likes: 0
From: Chanhassen MN
Vacuum??
Help!
Thread Starter
Heel & Toe
Joined: Sep 2011
Posts: 16
Likes: 0
From: Chanhassen MN
Any hesitation/missing before it craps out?
How does it run when it's actually running? Full rpm range and full power?
I've had a few issues with my 91 where it would die, run the next day, etc.
Once was the coil, once was the icm, once was the pick-up coil, once was a plug wire falling off, once was a distributor gear stripping (modded engine), etc.
Any trouble codes/ses light when it dies? When it goes to restart, will it crank but not fire? Like the guys above said...need to know if its fuel/spark. Get a fuel pressure gauge and start with that, it's the easiest to check.
How many miles on the car since you've owned it? Do you know the maintenance history?
Mike
How does it run when it's actually running? Full rpm range and full power?
I've had a few issues with my 91 where it would die, run the next day, etc.
Once was the coil, once was the icm, once was the pick-up coil, once was a plug wire falling off, once was a distributor gear stripping (modded engine), etc.
Any trouble codes/ses light when it dies? When it goes to restart, will it crank but not fire? Like the guys above said...need to know if its fuel/spark. Get a fuel pressure gauge and start with that, it's the easiest to check.
How many miles on the car since you've owned it? Do you know the maintenance history?
Mike
Not sure!!
Thank you everyone for your help!
M
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
When the car dies, get out, put a fuel pressure gauge on it, and check for spark. What do you see? Help us, help you.
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Thread Starter
Heel & Toe
Joined: Sep 2011
Posts: 16
Likes: 0
From: Chanhassen MN
Any hesitation/missing before it craps out?
How does it run when it's actually running? Full rpm range and full power?
I've had a few issues with my 91 where it would die, run the next day, etc.
Once was the coil, once was the icm, once was the pick-up coil, once was a plug wire falling off, once was a distributor gear stripping (modded engine), etc.
Any trouble codes/ses light when it dies? When it goes to restart, will it crank but not fire? Like the guys above said...need to know if its fuel/spark. Get a fuel pressure gauge and start with that, it's the easiest to check.
How many miles on the car since you've owned it? Do you know the maintenance history?
Mike
How does it run when it's actually running? Full rpm range and full power?
I've had a few issues with my 91 where it would die, run the next day, etc.
Once was the coil, once was the icm, once was the pick-up coil, once was a plug wire falling off, once was a distributor gear stripping (modded engine), etc.
Any trouble codes/ses light when it dies? When it goes to restart, will it crank but not fire? Like the guys above said...need to know if its fuel/spark. Get a fuel pressure gauge and start with that, it's the easiest to check.
How many miles on the car since you've owned it? Do you know the maintenance history?
Mike
Thread Starter
Heel & Toe
Joined: Sep 2011
Posts: 16
Likes: 0
From: Chanhassen MN
[QUOTE=Tom400CFI;1587278828]Vacuum? I don't know. No one does. It's not likely that it's "vacuum", but you're totally missing the point that I made above. You have to do a little work here. If you want WAG's we can give you plenty of that, but what is that worth? Not much.
When the car dies, get out, put a fuel pressure gauge on it, and check for spark. What do you see? Help us, help you.[/QUOTE
Thank you Tom!
I am going to tape a fuel pressure gauge to the windshield and see what happens when it dies. I also have the snap on tool which should show me codes.
Thank you so much for your help!
When the car dies, get out, put a fuel pressure gauge on it, and check for spark. What do you see? Help us, help you.
[/QUOTEThank you Tom!
I am going to tape a fuel pressure gauge to the windshield and see what happens when it dies. I also have the snap on tool which should show me codes.
Thank you so much for your help!
Pro
Joined: Jun 2013
Posts: 586
Likes: 26
From: Orange Park FLORIDA
check the ground connection from your battery to the frame. Corrosion and heat can cause too much resistance to allow enough current flow. After it cools the resistance decreases, allowing it to start.
Melting Slicks
Joined: May 2010
Posts: 2,082
Likes: 3
From: Conowingo Maryland
when it is acting up is the best time to dianiose the problem. For the most part with what you are saying it is going to be 1 of 2 things fuel pump craping out or ign module craping out. If you have a fuel pressure gauge hook it up as soon as it dies and check fuel pressure to see what you have If you do not have a pressure gauge push in the shreader valve where you would hook a gauge to you should have a strong steady burst of fuel. If you have some one with you have them turn trhe key to on while you hold in the shrader valve again you should have a steady burst if fuel if not it is going to be the fuel pump. The other thing to check is the spark kinda hard to check on your own but you need to remove a plug wire off a plug and put a screw driver or something on the end and hold it about a 1/4 in or so away from the metel of the engine have some one crank the engine you should get a nice steady spark for the gap. Having a module fail while going down the road is rare they seem to die after you shut the engine off and then come back to start them the fuel pump can cramp out at any time and they do like to come back to life after they cool down. I would look real hard at the fuel pump
Le Mans Master
Joined: Aug 2007
Posts: 8,735
Likes: 412
From: WV
If you do like the guys above are telling you, it will save a bunch of money wasted throwing parts at the car, instead of diagnosing the real problem... .If you want us to "guess", my guess would be it's the IAC..These are affected by the heat when there going bad, and it sounds like your problem may be heat related since you have to wait awhile before the car will start again...But coils can also be affected by heat ,as can ECMs, and so can fuel pumps....WW
.If you want us to "guess", my guess would be it's the IAC..These are affected by the heat when there going bad, and it sounds like your problem may be heat related since you have to wait awhile before the car will start again...But coils can also be affected by heat ,as can ECMs, and so can fuel pumps....WW
Last edited by WW7; Jul 5, 2014 at 06:59 AM.
Thread Starter
Heel & Toe
Joined: Sep 2011
Posts: 16
Likes: 0
From: Chanhassen MN
Oh, I know...
Right. I would like to fix it, not change parts that are not the problem. I am not as smart as you guys though, so I do what I can. I always appreciate the advice I get on this forum, I have learned a lot about my car, and I really enjoy driving it and working on it to make it reliable, after 22 years!
M
M
Thread Starter
Heel & Toe
Joined: Sep 2011
Posts: 16
Likes: 0
From: Chanhassen MN
Thank you WW7
If you do like the guys above are telling you, it will save a bunch of money wasted throwing parts at the car, instead of diagnosing the real problem... .If you want us to "guess", my guess would be it's the IAC..These are affected by the heat when there going bad, and it sounds like your problem may be heat related since you have to wait awhile before the car will start again...But coils can also be affected by heat ,as can ECMs, and so can fuel pumps....WW
.If you want us to "guess", my guess would be it's the IAC..These are affected by the heat when there going bad, and it sounds like your problem may be heat related since you have to wait awhile before the car will start again...But coils can also be affected by heat ,as can ECMs, and so can fuel pumps....WWThank you, I am going to look into heat related issues, but I cannot get the car to fail if it's up to max temp, fans on etc.. It only seems to stop after over an hour of driving.
I look forward to any advice you may have though!
Thread Starter
Heel & Toe
Joined: Sep 2011
Posts: 16
Likes: 0
From: Chanhassen MN
when it is acting up is the best time to dianiose the problem. For the most part with what you are saying it is going to be 1 of 2 things fuel pump craping out or ign module craping out. If you have a fuel pressure gauge hook it up as soon as it dies and check fuel pressure to see what you have If you do not have a pressure gauge push in the shreader valve where you would hook a gauge to you should have a strong steady burst of fuel. If you have some one with you have them turn trhe key to on while you hold in the shrader valve again you should have a steady burst if fuel if not it is going to be the fuel pump. The other thing to check is the spark kinda hard to check on your own but you need to remove a plug wire off a plug and put a screw driver or something on the end and hold it about a 1/4 in or so away from the metel of the engine have some one crank the engine you should get a nice steady spark for the gap. Having a module fail while going down the road is rare they seem to die after you shut the engine off and then come back to start them the fuel pump can cramp out at any time and they do like to come back to life after they cool down. I would look real hard at the fuel pump
Le Mans Master
Joined: Aug 2007
Posts: 8,735
Likes: 412
From: WV
I had trouble with the IAC and put a new one in. I also removed the heat exchanger below the throttle body when I did this, as that is what the guys at TPIS recommended.
Thank you, I am going to look into heat related issues, but I cannot get the car to fail if it's up to max temp, fans on etc.. It only seems to stop after over an hour of driving.
I look forward to any advice you may have though!
Thank you, I am going to look into heat related issues, but I cannot get the car to fail if it's up to max temp, fans on etc.. It only seems to stop after over an hour of driving.
I look forward to any advice you may have though!
Just wanted to add.... The new ICMs come with a small tube of grease that "must" be spread on the bottom of the new module before installation , failure to use this grease can/will cause a failure of the IAC later on...
..WW
Last edited by WW7; Jul 6, 2014 at 09:15 AM.
Thread Starter
Heel & Toe
Joined: Sep 2011
Posts: 16
Likes: 0
From: Chanhassen MN
Well, I changed out the fuel pump last weekend, and the car has been running well. Took it out for some long drives, no problems. It has been very cool here in MN though, so I will have to see how it does when the weather turns hot. So far so good though. Thanks to everyone for the help!