Engine dying in reverse?
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- Idontlikereverse
- Posts: 13
- Joined: Sun Jun 09, 2019 4:03 pm
- Location: Halifax Nova Scotia
Engine dying in reverse?
Last summer I bought a 1979 633csiA. It had minor issues and wasn’t happy in reverse or at idle, but it made the 4000 kilometre journey back from Saskatoon to Halifax Nova Scotia with only a fuel line coming undone on the way. Since then ive done regular maintenance, but I noticed that after checking for compression it now dies in reverse. Once the car is warm it idles fine, but as it starts it needs gas in order to stay alive. I don’t know if this is a part of the reverse issue. I’ve jacked the car up to see if it would still die if there was no load on the tires and it still did. It seems like it’s stalling. If I give it gas while or just after putting it into reverse it still dies. I hope it isn’t a transmission issue... has anyone else dealt with this?
86 635Csi
79 633Csi (sold for a bad price )
13 335 6mt
79 633Csi (sold for a bad price )
13 335 6mt
- Ralph in Socal
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Re: Engine dying in reverse?
I would check for a fuel supply issue. Make sure pressure is not dropping far below about 45psi. Also check fuel volume by measuring the fuel discharged through the pressure regulator outlet. You should get about 3 liters (from my faulty memory) during one minute of collection.
Ralph
Ralph
There is a very fine line between "Hobby" and Mental Illness.
85 635csi Zinno Auto
84 528i Euro
83 635 Euro Arktik
81 528i Kastanien 5-speed
88 528e Bronzit (Granpa Car)
86 535i Auto (For Sale)
81 633 csi (retired)
85 635csi Zinno Auto
84 528i Euro
83 635 Euro Arktik
81 528i Kastanien 5-speed
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Re: Engine dying in reverse?
I was thinking the same as Ralph! Sounds as though you may have a blockage or poorly performing pump.
Last edited by Pod on Mon Jun 10, 2019 4:12 pm, edited 1 time in total.
- Idontlikereverse
- Posts: 13
- Joined: Sun Jun 09, 2019 4:03 pm
- Location: Halifax Nova Scotia
Re: Engine dying in reverse?
Thanks guys I’ll definitely give those a try I think you guys are right about it being a fuel delivery issue. I fixed its other problems and took it for a spin where I was trying to see if it would reverse at all, and it would sort of reverse for a few meters very jerk-ily if I was at about half throttle, but it would sound like it’s getting no gas and then eventually it would cut out and die. I have a feeling you guys are right. I can’t understand why this would only be a problem in reverse though, I lack a lot of knowledge when it comes to auto transmissions and fuel injection.
86 635Csi
79 633Csi (sold for a bad price )
13 335 6mt
79 633Csi (sold for a bad price )
13 335 6mt
- 86_6series
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- Joined: Mon Apr 02, 2007 10:08 pm
- Location: West Nyack, NY
Re: Engine dying in reverse?
So this stalling in reverse happened after a compression test.
Is it an auto tranny?
I can't think of any link between compression test and a reverse problem.
All I come up with is could be the neutral safety switch wires move
when shifting into reverse to cut out ign.
Just my $.02
Is it an auto tranny?
I can't think of any link between compression test and a reverse problem.
All I come up with is could be the neutral safety switch wires move
when shifting into reverse to cut out ign.
Just my $.02
86-635CSi
96-MB C220 SOLD
98-740i
71-Continental MK3
96-MB C220 SOLD
98-740i
71-Continental MK3
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Re: Engine dying in reverse?
Maybe because in reverse you don't rev the engine, but let it go back either at tickover or low revs? Does it drive forward @ tickover without the same problems?Idontlikereverse wrote: ↑Mon Jun 10, 2019 1:04 pm I can’t understand why this would only be a problem in reverse though
- Idontlikereverse
- Posts: 13
- Joined: Sun Jun 09, 2019 4:03 pm
- Location: Halifax Nova Scotia
Re: Engine dying in reverse?
I realize I never posted the solution - it was a crack in a Mass air flow hose.
This problem was super frustrating and the crack was only visible from below. Hopefully this will help someone one day.
This problem was super frustrating and the crack was only visible from below. Hopefully this will help someone one day.
86 635Csi
79 633Csi (sold for a bad price )
13 335 6mt
79 633Csi (sold for a bad price )
13 335 6mt
- RossDinan6
- Posts: 305
- Joined: Mon Jan 29, 2007 2:35 am
- Location: SW FL, USA
Re: Engine dying in reverse?
Not that I have an early car, Motronic or an auto, I am a bit curious. My thinking is there should be little or no difference in engine load in drive or reverse. why'd it stall in reverse and not in drive. The air flow/leak should be the same.
Inquiring minds want to know
Inquiring minds want to know
Ross
'84 633 Dinan turbo
'84 633 Dinan turbo
- 86_6series
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Re: Engine dying in reverse?
First--thanks for posting the solution.
After reading this I have the same question as RossDinan6.
Could the crack open wider with the engine torqueing in reverse?
After reading this I have the same question as RossDinan6.
Could the crack open wider with the engine torqueing in reverse?
86-635CSi
96-MB C220 SOLD
98-740i
71-Continental MK3
96-MB C220 SOLD
98-740i
71-Continental MK3
- Idontlikereverse
- Posts: 13
- Joined: Sun Jun 09, 2019 4:03 pm
- Location: Halifax Nova Scotia
Re: Engine dying in reverse?
I think In hindsight it did occasionally die in drive. I guess there may be more load on the engine in reverse causing it to sputter and die. I remember the idle to be quite high in park and then in drive it would go down to about 6-700 rpm. Maybe when in reverse it would go too low and die.
One time I put it in reverse and floored it right away. If I remember correctly it started lurching just like when you are running out of fuel.
I’m fairly unsure though, it has been a little while and the exact details have escaped me.
This is the part I am referring to having a crack - the tube leading to the maf.
One time I put it in reverse and floored it right away. If I remember correctly it started lurching just like when you are running out of fuel.
I’m fairly unsure though, it has been a little while and the exact details have escaped me.
This is the part I am referring to having a crack - the tube leading to the maf.
86 635Csi
79 633Csi (sold for a bad price )
13 335 6mt
79 633Csi (sold for a bad price )
13 335 6mt
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Re: Engine dying in reverse?
I hate to say it, but, that hose crack should not have had any affect on idle, or running, as it's ahead of the afm. Glad to hear it's working though!
- Idontlikereverse
- Posts: 13
- Joined: Sun Jun 09, 2019 4:03 pm
- Location: Halifax Nova Scotia
Re: Engine dying in reverse?
That’s another thing that never made sense to me.
I took it to a euro shop who found the crack and replaced it. Everything ran perfectly after that. I didn’t think it should have made a difference either, but other people said it can cause it to run lean?
I’ve heard of aftermarket cold air intakes failing and causing a rough idle but I’m not sure why that’s the case.
I hope the car is still running fine , but it has since replaced with a bigger project 635.
I took it to a euro shop who found the crack and replaced it. Everything ran perfectly after that. I didn’t think it should have made a difference either, but other people said it can cause it to run lean?
I’ve heard of aftermarket cold air intakes failing and causing a rough idle but I’m not sure why that’s the case.
I hope the car is still running fine , but it has since replaced with a bigger project 635.
86 635Csi
79 633Csi (sold for a bad price )
13 335 6mt
79 633Csi (sold for a bad price )
13 335 6mt
- RossDinan6
- Posts: 305
- Joined: Mon Jan 29, 2007 2:35 am
- Location: SW FL, USA
Re: Engine dying in reverse?
The ECU can not tell if there is a leak anywhere from the air filter inlet to the AFM. Anything after the AFM will be noticed, this is unmetered air. Try pulling your dipstick that will introduce unmetered air as well.
I suspect they found something minor, or accidentally fixed it without knowing it.
I suspect they found something minor, or accidentally fixed it without knowing it.
Ross
'84 633 Dinan turbo
'84 633 Dinan turbo