Car just died on me

brtele · Post by **brtele** » Thu Dec 17, 2015 10:38 pm

I just changed the upper radiator hose and bled the system and the car was running just as it did before. Once it was up to temp or close to, I took it for a spin around the block and it was running fine. I pulled a u-turn and down shifted and the car just died on me.

I could get it to turn over and make small fires, but it wouldn't run. So I sat for about 5 minutes and would periodically try to turn it over. All of a sudden it fired and ran awful until I feathered the gas up to about 1500rpm.

I babied it back to work about a 1/2 mile away and it ran fine. I sat with it running in the parking lot and it idled fine. I decided to slowly run the rpms up in neutral and it did fine all the way up to 3500rpm. I held 3500 for about 5 sec and decided to abruptly let off the throttle to see if the car could "catch" itself. It couldn't and died. I could not start it up again.

I'm leaning towards fuel supply and would like to see if anyone has any pointers.

Distributor Cap is dry and didn't get wet during coolant bleed.

Thanks,
Brandon

josh · Post by **josh** » Thu Dec 17, 2015 10:44 pm

I very recently had a similar problem. viewtopic.php?t=21646&postdays=0&postorder=asc&start=15

Mine turned out to be the main pump, but before you order a new one you should check the fuel sock on the pre-pump, and the main filter.

tschultz · Post by **tschultz** » Fri Dec 18, 2015 12:58 am

^^ Sounds about right to me also.

brtele · Post by **brtele** » Fri Dec 18, 2015 6:01 pm

I know this sounds weird, but i've got to ask. When my upper radiator hose was replaced, i've ordered an exact replacement from the web, but in the meantime have replaced it with a flexible "ribbed" hose. Would this type of hose be causing a problem?

I started the car this morning and it ran great until it felt like the thermostat kicked in - then started running really rich.

I've checked the cold start valve by removing fuel supply from it and the car continues to run rough/rich.

I've disconnected the O2 sensor just to see if that was the issue. Still runs rich.

I took the ICV off and it has a little rattle when I shake it.

I'm getting good fuel pressure.

I haven't checked fuel injectors or spark, but I believe my spark/injectors are good due to it firing great while cold.

If I gently tap on the thermostat housing and particularly the temp switch, the idle really jumps around.

With the engine temp gauge just above blue, the coolant temp sensor ohms 577.

I'm going to replace the upper hose with the correct hose, but just wanted to see if this type of ribbed hose could cause coolant flow issues and create bad signals from the coolant sensors. Just a thought.

sansouci · Post by **sansouci** » Fri Dec 18, 2015 6:37 pm

Could it be corroded connections on top of the T-stat housing? Clean 'em all up and see what happens. Cost you $0

brtele · Post by **brtele** » Fri Dec 18, 2015 7:13 pm

Good idea. I'll clean up all the connections.

brtele · Post by **brtele** » Fri Dec 18, 2015 10:51 pm

I forgot to mention that the coolant temp sensor ohm'd out at 1045 about 30 minutes later. I won't get back to the car tomorrow, but curious to know if the sensor could make the fuel mixture rich enough to keep it from running once at operating temp

brtele · Post by **brtele** » Sun Dec 20, 2015 3:15 pm

I know I'm stretching here, but this happened immediately after I replaced the upper radiator hose with the flexible ribbed hose. Does anyone know if the ribbed house could cause a flow issue bad enough to cause a no run condition.

Thanks

hornhospital · Post by **hornhospital** » Sun Dec 20, 2015 4:59 pm

No way the hose had anything to do with it.

brtele · Post by **brtele** » Sun Dec 20, 2015 5:45 pm

I agree .it's just very strange that the very next start up after the replacement is when this happened. Also the realoem diagram of my thermostat housing appears different than mine regarding sensor placements.

tomorrow I'll be able to test all of the sensors at dead cold to see what my baseline is.

The number 1 injector got really wet when replacing the hose. Any concern there?

Any other recommendations are very helpful.

Thanks

slofut · Post by **slofut** » Mon Dec 21, 2015 2:23 am

brtele wrote:I agree .it's just very strange that the very next start up after the replacement is when this happened.

Any other recommendations are very helpful.

Thanks

How long have you had this car? Since owning two nice examples I've found this not to be unusual... Flame suit ON.

GripGreg · Post by **GripGreg** » Mon Dec 21, 2015 6:27 am

Ken is right; it has nothing to do with the hose!
The same thing happened to me & I posted my issue here maybe three years ago?
Well, a fellow poster gave me a list of about 12 grounds to clean.
Including underneath the fuse box on Buster, (E12/E24) I think on the bell housing?
At the starter & maybe somewhere on the bulkhead? On & on.
Generally, places we tend to forget. I used WD-40 & a clean rag.
He has never quit on me since then!
Thank You, Sir!=D>

This is a cheap possibility; like free?

There might be a loose ground but, that's all it takes.
Good Luck,,,,Greg

brtele · Post by **brtele** » Mon Dec 21, 2015 7:44 pm

I'm having trouble with RealOEM vs my tstat housing. I'm assuming my sensors are as follows:

Bottom left Orange = Coolant Temp Sensor
Middle left Brown = Temp Sending Unit - Warning Contact
Upper left = Temp Time Switch
Upper Right Yellow = Temp Switch

The Bentley Book and the RealOEM diagram both show vacuum hoses coming off of the Tstat housing. I have no vacuum hoses coming off of the housing. Is this the correct set up for my car.

My VIN ends in 6725244.

Thanks and hoping to figure this one out without having to go to the shop. I'm gonna figure this damn car out.

hornhospital · Post by **hornhospital** » Mon Dec 21, 2015 8:44 pm

That's pretty odd. You have an early thermostat housing (note the "4.1" cast into the body), but it has multiple sensor ports like a 4.2 (later) housing. Neither of my E24s have vacuum lines to any of the sensors on the thermostat housings.

brtele · Post by **brtele** » Mon Dec 21, 2015 9:01 pm

I just checked again and the casting definitely states 4.1. Is my description of the sensors correct? I want to be sure I'm understanding what sensors do what.

Thanks,

brtele · Post by **brtele** » Tue Dec 22, 2015 2:40 am

So I sanded clean the tstat sensors and blew them off with air. Connected everything back up and started the car. It ran awful from the start. It sounded like it was running really rough (maybe on 5 cylinders) and smelled really rich.

I'm trying to determine if I have sufficient spark to each cylinder. I started with plug wire resistance to make sure they're good.

#1 plug wire = 5.88
2 - 6.02
3 - 5.86
4 - 5.97
5 - 5.96
6 - 6.3

Nothing seemed out of sort on the wires.

I'm going to check plug wire spark by plugging them individually into a spark plug to check for blue spark when grounded to the block per Bentley.

I'm also going to pull each plug to see if any of them are really fouled or wet.

Any other ideas?

I don't think it's fuel pressure, but was going to install a Schrader valve inline just before the fuel rail to be able to check fuel pressure whenever I need to in the future.

Thanks,

brtele · Post by **brtele** » Tue Dec 22, 2015 2:48 pm

I checked my oil this morning just to ensure I didn't have coolant in the oil (I just had the head gasket replaced and wanted to make sure). While the oil still looked Brad Penn Green, it had a very slight gas smell to it. I'm assuming this might be due to wash down on a cylinder that might not be working.

To reduce fuel supply to the cylinders while I'm checking spark at each plug, would it be bad to remove the fuel pump relay next to the main relay? Please let me know if it's a bad idea to remove the fuel pump relay while pulling each plug to test for spark.

Thanks,

Brandon

hornhospital · Post by **hornhospital** » Tue Dec 22, 2015 5:38 pm

That will work fine. No harm.

brtele · Post by **brtele** » Tue Dec 22, 2015 11:30 pm

Didn't get a chance to install the fitting in the fuel line in order to check fuel pressure. Will probably do that in the next few days. I've never relieved the fuel pressure on this fuel system before. I was going to very slowly pull the line from the fuel rail supply with a towel wrapped around it. Bentley states to pull it very gently in order to let the pressure relieve slowly. I'm not anticipating any crazy fuel spewing from the system, but just wanted to run my method by the forum.

Also had a chance to check resistance/voltage on a few areas (I'm learning a lot more about what type of Motronic I have. I believe it's the Motronic Basic based on the Diag Plug has (15) pin).

Temp Coolant Sensor at 68F = 2735

ICV = 9.2 and 11.3vdc when key is on. I can feel the ICV click when the key is turned by a helper, but it doesn't "hum" or "vibrate". I even have my hand on it to feel for the vibration and all I can feel is a slight tap right when 12vdc is applied to it.

Speed/Reference Sensors
Both pulled 1009 between 1-2 and a closed loop on 2-3 and 1-3. Is this correct?

Please let me know if anything looks out of sorts.

Thanks,
Brandon

slofut · Post by **slofut** » Wed Dec 23, 2015 1:34 pm

brtele wrote:Didn't get a chance to install the fitting in the fuel line in order to check fuel pressure. Will probably do that in the next few days. I've never relieved the fuel pressure on this fuel system before. I was going to very slowly pull the line from the fuel rail supply with a towel wrapped around it. Bentley states to pull it very gently in order to let the pressure relieve slowly. I'm not anticipating any crazy fuel spewing from the system, but just wanted to run my method by the forum.

Also had a chance to check resistance/voltage on a few areas (I'm learning a lot more about what type of Motronic I have. I believe it's the Motronic Basic based on the Diag Plug has (15) pin).

Temp Coolant Sensor at 68F = 2735

ICV = 9.2 and 11.3vdc when key is on. I can feel the ICV click when the key is turned by a helper, but it doesn't "hum" or "vibrate". I even have my hand on it to feel for the vibration and all I can feel is a slight tap right when 12vdc is applied to it.

Speed/Reference Sensors
Both pulled 1009 between 1-2 and a closed loop on 2-3 and 1-3. Is this correct?

Please let me know if anything looks out of sorts.

Thanks,
Brandon

ICV stuck closed, take it off and thoroughly clean with carb cleaner, check that it rotates before you put it back on. Would explain running rough and rich at idle too.

brtele · Post by **brtele** » Wed Dec 23, 2015 8:50 pm

I cleaned the ICV with carb cleaner and made sure the gate on the side moves freely and the vane from the top moves in either direction. I've looked for a good explanation how the internals of my 2-wire ICV works to verify it's moving correct, but can't find one. I cleaned the contacts and again made checked ohms (10.2) after cleaning. I have 12vdc at contacts when ignition is on and the valve clicks and I can see the side "gate" quickly close the open back up. There is no humming and/or vibrating.

I've checked spark on each cylinder and all (6) are firing. I have not pulled plugs and see if the spark is blue when grounded to the block.

Car still runs awful and once warm will fire, but not stay running.

Also, when I pull the oil dipstick, it makes no real noticeable difference to the run cycle. When it ran great, if I pulled the oil stick, it would start burping and farting.

What I'm doing next:
- I just got a Schrader valve to install just before the fuel rail to check fuel pressure. Installing tomorrow, once engine is dead cold.

- Cleaning/Wire brushing multiple grounding points and applying dielectric grease to keep them clean.

- I've started replacing a few vacuum lines, but the ones I pulled looked really good and I've checked the throttle body tube when off for any leaks. Most of the lines look pretty new.

Any suggestions are very welcome. Please let me know if my 2-wire ICV should be making more noises with the engine off, but key in run position.

GripGreg · Post by **GripGreg** » Wed Dec 23, 2015 9:04 pm

I think you answered your own question when you pulled the dipstick but, nothing changed!
It appears you may have a vacuum leak!
These cars run closed systems so any air getting in creates havoc!
Good luck,,,,Greg

Brucey · Post by **Brucey** » Wed Dec 23, 2015 9:37 pm

shows all the parts on the thermostat housing.

You can identify your motronic from the Bosch part number of the ECU.

I would certainly not recommend that you install a Schrader valve to measure fuel pressure; you will lose fuel when you connect and disconnect any gauge and there is not guarantee that any rubber seals in a standard gauge will be OK with petrol on them.

It is best to get a gauge with a T piece and to plumb it in temporarily.

cheers

brtele · Post by **brtele** » Wed Dec 23, 2015 10:00 pm

Greg, thanks I'm going to go through all the vacuum lines and check everything.

Brucey, thanks for the tstat pic. I think I'm getting closer to understanding the sensors on my tstat and I believe they're all working properly (at the moment).

Regarding the Fuel Pressure Tester, I'm using the Innova 3640

http://www.autozone.com/test-scan-and-s ... 73356_0_0/

I'll make a piece that will fit just prior to the fuel rail temporarily. Although I don't see any pieces on the T that would typically fail, but again why add something else in that could fail.

I'll know more tomorrow and keep updates coming.

Thanks for the help and again it's nice to start understanding how some of the sensors work on this car.

brtele · Post by **brtele** » Wed Dec 23, 2015 10:11 pm

One more thing I forgot to mention. When I run the rpms up to 2K it starts to run a little better, but still sounds like it missing or running rough. This would lead me to believe the ICV is not the contributing factor due to the rough running above idle.

bigcoupe.com

Car just died on me

Car just died on me

Cleaned ICV - but no humming