aventari

Hey all, this will be long so bear with me car is an 89 951 completely stock.. maybe you can help with troubleshooting ideas.

I left San Diego today and am driving out to Kansas for xmas and then driving back. I went 11 hours today--right now I'm in New Mexico. Ok enough back story

I thought the car was ready for the trip until a few days ago. I was starting the car to go to work on a SUPER cold morning. The car started, but only ran on 3 cylinders for about 30 seconds. . Revving the motor didn't change anything, it was still like 3 cyls. After 30 secs it magically started running fine. It didn't sputter when i revved it, just ran like a plug wire was disconnected. It concerned me but I wrote it off to the extreme cold.

Today when leaving for the trip I tried to start the car and it wouldn't start. I cranked it for 20 seconds or so a couple times and it was not trying to catch, just cranking over and over. I tried once more time and it started right up.

I decided to go anyway.

About 300 miles out of San Diego, the car has been running perfect. I pull in to get gas. I turned the car off and got gas and checked all fluids and everything under the hood. When I got in to start it, the engine just turned over and nothing happened. I tried it twice, and then pulled the DME relay and jumpered the connector. I went to the back of the car and heard the fuel pump running, I got in and the car fired right up. I turned the car off, pulled out the jumper wire, and reconnected the DME relay. The car started right up again. So the jumper wire seemed to fix it, indicating the problem was a bad DME relay. However, when I plugged the relay back in, it worked again. So I don't know for sure if that was the problem or not.

I got to the hotel tonight and turned the car off. I've restarted it 3 times so far with zero problems. I don;t know if it will act up again.



Now I've had the car a few years but only maybe driven it 3-4000 miles. In that time I've had 3 DME relays die on me. Is this a common problem or is my wiring or pump probably bad?
Also when I got the car, it would randomly die on me. I replaced a lot of things, but what finally fixed it was a new coil. I used an MSD Blaster 2 coil I had laying around and it's been working fine. I did bring a spare VW Rabbit coil on this trip in case I the car dies I can swap the Rabbit coil and see if that fixes it.

This car was a basketcase when I bought it, so I've put a lot of new stuff on in the past few years. As for stuff thats new on the car that could be related to this problem:
rebuild head by Lindsey
Injectors cleaned and balanced
new rotor/cap/wires/plugs
all new stock intake hoses (incl. jboot)
all new stock vacuum lines and hoses
new crank ref sensor (broke the old plug)
battery is good and fully charged



Any ideas?
Troubleshooting tips if it dies or won't start again? I have a my tools and a lot of wiring parts/multimeter.



Oh yeah there was some crazy snow in the mountains of Arizona, traffic was crawling at 15 mph and when I would touch the brakes, the ABS would engage, but the 951 handled it very well and I made it through!

CarbonRevo

where at in Kansas are you headed to?

Ski

This can be a finicky subject but it sounds like you might have some ground issues, check the ones at the back of the bell housing first. Tap on the relay before removing it next time, just an old trick.

When it doesn't start, check to see if the tach is moving, if not, speed sensor. There was a really good " No Start" thread a few months back, might want to search if you need to.

KuHL 951

I would first check that connector again at the speed sensor bracket. Even a new sensor won't sit right if the female side of the plug has a loose pin or slightly cracked housing. The other thing, possibly your DME has a bad solder trace; try kicking the passenger floorboard area with your foot; if it starts you need a new DME. Those sensors have been the bane of too many owners to not check twice.

LFA951

Next time, leave her on while you're getting gas!

Josh B

I wonder how the wiring harness is at the connectors to your injectors? Seems like all the dead dme relays is a sympton of something else. Might not hurt to buy the replacement wiring harness connectors for the injectors from Lindsey....Also I would keep a spare DME computer around. Have you ever had water leaking problems from the bottom of the battery tray?

aventari

Thanks for all replies, I'll keep the thread updated. If it doesn't start again I'll jiggle the speed sensor harness and kick the floorboard and jump up and down three times.

Headed to Great Bend, near Dodge City


Heh yeah I did that the second time, it killed me not to check the oil though heh

I've never had leaking problems that I know of but it's a possibility. I'll check for wetness.

Sounds like I need to do some ground cleaning/extra ground wires and inspect some old suspect wiring when I get to my Dad's in Kansas

Thanks again!

Ski

If you take the grounds loose back there(tight), cover the hole in the bell housing with masking tape or stuff a paper towel in there. You should have 1 bolt and one nut for the two grounds.

+1 for Josh, and you can get connectors and the OEM boots too.

M758

Electrical grounds could be an issue. It could also a bad wire someplace that randomly loses a connection. Wire could be frayed and failing. That could be causing the DME relays to break. Hard to say for sure, but it sounds 100% electrical. However finding that can take time. Sand paper to the grounds is probably the best thing to try first. It is easy to do and cheap. It can't hurt.

User 41221

I'm thinking cold solder joint on the DME. FUn stuff, trying to troubleshoot intermittent electrical problems on a road trip.

If you were coming to KC, I'd offer up the services of the KCWS, but Great Bend is a bit of a drive from KC. Keep us posted!

Regards,

aventari

I made it to Kansas today, had some trouble in the mountains in New Mexico with snow, almost didn't make it through. I have brand new tires on the Porsche which is good, but they are Sumitomo HTR-Z tires which are a summer performance tire and NOT snow tires.. I got caught in some pretty heavy snow on the road.

There was one really scary part where I was in a long line of cars creeping along a normally 75mph highway at 10-15 mph with packed ice/snow on the ground, I was sliding around and couldn't even see the road under the snow/ice. Going up a hill at one point we passed a stuck BMW 3 series and a stuck big rig next to each other. It was on a steep incline and I was going past them and started to lose traction and slow down. I had tried to get a run at this section because I knew it would be tough so I was going about 20mph, but the back tires started slipping and I was slowing down and and starting to go sideways. I had to spin the rear tires and counter steer a lot and the car ALMOST got stuck until I hit a patch of slush and got traction and got the car straight again and kept moving. That was really scary, my heart was in my throat and I almost slid into a ditch or another car. Before that we had passed a stuck snow plow and I knew that it wasn't going to be good. heh


Anyway with 1 exception the car ran good. I turned it off 3 or 4 times and it started up again every time.

The 1 problem was at one point I was going down a hill, floored it in 5th gear from 75 up to about 120mph and I was at WOT and full boost and the engine just cut out. I immediately let off and gave it a little gas and the car was still running normally. I floored it again for a second and once it hit full boost, it felt like I hit a fuel cut again.

I babied the car most of the rest of way because I was scared of it completely dying. But before I got to my destination I did a few full throttle runs in 3rd and 4th gears and didn't have any problems. the 'fuel cut' issue that I felt didn't occur again..

I have no idea if this is related but it's worrying me for my 1500 mile drive back heh.

Bri Bro

Sounds like you are pulling too much power through the DME relay and burning up the contacts. My first guess would be the fuel pump but several other circuits run through the DME relay. Check how much current you are drawing through the relay. Does the relay run a little warm?

Droops83

+1 on too much current through the relay if you have gone through that many. I'd ordinarily suspect the fuel pump but in your case it sounds like the DME side of the relay is at fault since from your description it all of the sudden wouldn't start and when it did restart it fired right away. When my DME relay failed it was a solder on the fuel pump side, the engine acted like it ran out of gas, and when I jumped the relay pins it had to build up fuel pressure again before the engine started.

Kudos on making the journey in your 951, I just drove from Santa Barbara to Houston in my '86. Only problem was that my exterior door handle broke at a gas station and I have to go in through the other door. I got a lot of heavy rain in AZ but no snow, glad you made it!