After 4 years of sititng, I've finally gotten my 951 back on the road with a rebuilt CHRIS WHITE 2.7L ( I highly endorse his rebuild & support - which included many many issues NOT tied to the engine rebuid) engine powering my toy/daily driver. I have been driving the car since this past February with no real issues until now.

Within the past 2 weeks, my 951 will SUDDENLY LOSE POWER while driving down the road (has happened on a major highway once - thank god I was driving in the slow right hand lane). This has happened 3x. Other than the car suddenly hesitates/vibrates and then all of the sudden loses power and shuts off - there are no other warning signs.

One thing that I have noticed - is that this happens - only within 10-15 mins of start up. After the car is warmed up and driven for a good 20+ mins - I have not had it shut down on me - yet (fingers crossed).

Let me note the following items that were replaced when the rebuilt 2.7L was installed by me and my mechanic (he's a friend too) last winiter.

Rebuilt DME
LR Knock sensor harness
LR fuel injector harness
Replaced "O" rings on LR fuel rail (failed after 4 yrs of sitting)
New coil
New 3bar FPR
New LR TPS wiring harness
New speed & reference sensors
New Walbro fuel pump
Replaced all vacum lines
New turbo after-run pump
turbo oil restrictor (LR Super48 is a Garrett turbo & smoked big time until the restrictor was put in)
New (rebuilt?) TPS
All the grounds were cleaned prior to engine install


The car is also equipped with the LR Stage 2 MAF (their old system), MAFterburner, and 55 lb Siemens injectors (no resistors). In trying to resolve the problem, I replaced the DME relay, but the same thing happened. In hindsight, I do remember that in trying to trouble-shoot/tune the car this past Winter/Spring we did disconnect the factory 02 and used a wideband (AEM Uego), the factory 02 is still disconnected (will reconnect this evening and see the results) - could that all of the sudden cause the shut-down issue?

This issue didn't happen before the extreme hot weather hit the East Coast these past 2 weeks, that's probably a coincidence, but it also could be contributing to the cause of my sudden power shut-downs while driving.

Any ideas would be appreciated.


jy951


Any ideas?

 

Someon else was having a similar problem, not too long ago. I posted a checklist on things to check, take a look at this Thread

 

Who rebuilt the DME?

And what exactly did they do to the perimeter ground?

Because 10 minutes, hot weather, seperating PC ground.....seen that show many times.

 

When was the sparkplugs last replaced? How's the wear on your sparkplugs wiring? I know this is basic stuff but you never know sometimes we overlook that.. I had a VW golf that had similar symptoms, turned out to be bad wiring and old sparkplug giving away when temperature was too humid. Replaced that and all was well again.

 

Had something very similar a few months ago, turned out to be a short at the reference sensor plug on the harness side. I see you replaced the speed and reference sensors but may want to carefully inspect the DME side connectors (my short was right at the base of the connector and it was hard to see).

 

I had the same issue. I got a new reference sensor and the car has been great ever since.

 

Thanks John - Will do!

 

I forget who rebuilt the DME for them - definitely aftermkt

 

Bought them from Jason @ Paragon Parts

 

Thanks!

 

I will check the DME side since I replaced the reference & speed sensors and the factory harness for them. I bought the LR harness for both.

 

I have noticed an overall difference since the reconnect but don't know if it will stop the power loss @ road speed. So far this evening - no power loss while cruising but that was the case when it was disconnected and the engine was warmed up.

Tomorrow (Thurs - June 2) will be the real test. If it stops within 10-15 mins of start-up, I will follow John Vitesse's chklist. I will also check the spark plugs and reference/speed sensor connections at the DME too.

Thanks for the feedback guys - much appreciated!

 

sorry to get off topic but can I see a closer pic of your vented panel plz

 

This sounds exactly like what was happening to me, turns out it was the DME computer, I would definitely try swapping that out.

 

I would guess it's from Deutsch Nine. I like it too!