What's This?

[sdg3205]

I've never noticed this before. It runs up to the diagnostic plug. I only see it now that the factory manifolds and cat are gone.

Looks like an old school TPS?

EDIT - the pics rotated 90 degrees left. so, turn your head 90 degrees left :)


391253912639127

[DMC-81]

That's the magnetic pickup and metal bracket for the diagnostic plug. I think the pickup gets a reading from the flywheel.

I replaced my plug and had to reinstall that plate. Major pain!

[sdg3205]

Does it serve a purpose? I read dwell right at the bulkhead. I thought that was the only thing the diagnostic plug was good for on our cars.

[DMC-81]

I think it can be used to read the dwell, but I'm not sure. Here's a thread that may help....

http://dmctalk.org/showthread.php?12226-Diagnostic-plug-uses-explained

[sdg3205]

yeah. 12v, ground and dwell.

[Bitsyncmaster]

The pickup plate on my car was just laying on the exhaust when I bought my car. Since there is no use for that signal (it must relate to RPM reading the flywheel teeth), I just removed the whole diagnostic connector.

[DMC-81]

Yeah, the gray wire between the pickup and the plug was burned/melted by the exhaust on my car. It had fallen out of the clear zinc clip sometime in the cars history. Plus one screw was missing on the bracket / protecting plate, allowing it to rattle slightly. I opted to replace it mainly for originality. Plus I may use it for dwell readings. Here are some pics:

39142

39143

39144

[sdg3205]

Did you remove the plate as well or did you leave it in place to keep debris out of the bell housing?

[Bitsyncmaster]

Did you remove the plate as well or did you leave it in place to keep debris out of the bell housing?

I think I put the plate back in (was 8 years ago). I remember I had to open up one of the holes to get it back on which is probably why it left off in the first place.

[dn010]

That plate has been off my car for 12+ years and I've had no adverse effects but now I'd like to reinstall it if I could ever find it.

[PJ Grady Inc.]

The plate and the attached lead serve an important diagnostic purpose but do not affect function. It is solely for getting a dwell reading when diagnosing lambda circuit issues. If the plate is removed only your mechanic will know for sure!
Rob

[sdg3205]

I'm removing the diagnostic plug. I take dwell from the FV pins on the bulkhead. I'll RTV a quarter over the hole left by magnetic sensor. It seems the plate would be good to keep in place to help prevent debris around the flywheel.

[Delorean Industries]

Most cars are without this. The stock plates are poorly coated to begin with. A stainless cover plate is available from DeLorean Industries. The design is slightly changed as there is no pick up hole and a tab protruding past the bell housing with pem inserts. Serves as mounting point for Bosch intercooler pump.

[PJ Grady Inc.]

The plate and the attached lead serve an important diagnostic purpose but do not affect function. It is solely for getting a dwell reading when diagnosing lambda circuit issues. If the plate is removed only your mechanic will know for sure! When we reinstall this plate, usually after replacing a clutch, it's SOP to reattach it with just the bottom bolt as the upper one is a bear to R & R and not really necessary.
Rob

[sdg3205]

Did they come with two bolts in place from the factory? Mine only had one bolt, like you mention. Makes me wonder if someone replaced the clutch before I bought the car.

[PJ Grady Inc.]

Most cars are without this. The stock plates are poorly coated to begin with. A stainless cover plate is available from DeLorean Industries. The design is slightly changed as there is no pick up hole and a tab protruding past the bell housing with pem inserts. Serves as mounting point for Bosch intercooler pump.

Ok Josh you got me....wtf is a "Bosch intercooler pump"? And why would you eliminate the pickup mtg hole because that is the plate's sole purpose on a stock Delorean?
Rob

[Delorean Industries]

The bosch intercooler pump is what provides flow within our air to water intercooler systems on turbo applications. The lower bell housing mounting points are optimal as the pump needs to be as low as possible to avoid cavitating and air pockets when priming on cold starts. The stock bracket serves as a decent block of point to keep clutch material etc from kicking out of the housing but I have yet to find a use from the stock pick ups that are usually broken anyways. When I made the replacement I deleted this component as I don't include the diag plug on any cars we service or build. I always set the CO and suggest to do so with a wide band compared to reading the dwell. If someone really wants to read the dwell then back probing the bulk head connectors is sufficient.

This is the intercooler pump we currently use. Different for boost applications as this pump moves more than the stock Bosch unit and affects intercooler flow efficiency in off idle situations from heat soak. (coolant moving too quickly through intercooler cores)

39208

[PJ Grady Inc.]

Did they come with two bolts in place from the factory? Mine only had one bolt, like you mention. Makes me wonder if someone replaced the clutch before I bought the car.
Yes two bolts but it's overkill on this part and yes someone probably replaced the clutch.
Rob

[PJ Grady Inc.]

The bosch intercooler pump is what provides flow within our air to water intercooler systems on turbo applications. The lower bell housing mounting points are optimal as the pump needs to be as low as possible to avoid cavitating and air pockets when priming on cold starts. The stock bracket serves as a decent block of point to keep clutch material etc from kicking out of the housing but I have yet to find a use from the stock pick ups that are usually broken anyways. When I made the replacement I deleted this component as I don't include the diag plug on any cars we service or build. I always set the CO and suggest to do so with a wide band compared to reading the dwell. If someone really wants to read the dwell then back probing the bulk head connectors is sufficient.

This is the intercooler pump we currently use. Different for boost applications as this pump moves more than the stock Bosch unit and affects intercooler flow efficiency in off idle situations from heat soak. (coolant moving too quickly through intercooler cores)

39208
Thanks for the explanation. I already knew it had to do with your turbo setup but I doubt too many others did. I like to keep the diagnostic plug functional where possible because not everyone has an emissions tester or oscilloscope but a dwell meter can be had by all.
Rob

[Bitsyncmaster]

Ok Josh you got me....wtf is a "Bosch intercooler pump"? And why would you eliminate the pickup mtg hole because that is the plate's sole purpose on a stock Delorean?
Rob

Have you or anyone else ever used that pickup signal for anything? Does it just relate to engine RPM or TDC (top dead center)?

[PJ Grady Inc.]

Have you or anyone else ever used that pickup signal for anything? Does it just relate to engine RPM or TDC (top dead center)?

We use it routinely for checking the lambda circuit function and it is a handy indicator for setting the base CO adjustment when not using a scope. Every car was fitted with it from the factory and we always reinstall them on a stock engine. It's there for an important diagnostic purpose.
Rob

[Bitsyncmaster]

We use it routinely for checking the lambda circuit function and it is a handy indicator for setting the base CO adjustment when not using a scope. Every car was fitted with it from the factory and we always reinstall them on a stock engine. It's there for an important diagnostic purpose.
Rob

I mean the sensor going to the flywheel. The dwell reading can be got at the two pin connector that connects to the diagnostic connector. What I'm saying is that flywheel sensor is never used (I think).

[DMCVegas]

I mean the sensor going to the flywheel. The dwell reading can be got at the two pin connector that connects to the diagnostic connector. What I'm saying is that flywheel sensor is never used (I think).

http://i.imgur.com/ytVvtnJ.gif?noredirect

Wait a minute here.... Is it possible to use that sensor as a crank trigger for EFI Conversions?

[opethmike]

http://i.imgur.com/ytVvtnJ.gif?noredirect

Wait a minute here.... Is it possible to use that sensor as a crank trigger for EFI Conversions?

You'd also need a cam signal. Otherwise, the ECU wouldn't be able to time the injection pulses correctly.

[DMCMW Dave]

I'm not 100% sure, but I don't believe that the flywheel has anything in it to actually trigger that sensor.

BTW I believe Rob is talking about the other pair of wires on the diagnostic connector, the Orange one in particular, which comes from the Lambda ECU for monitoring purposes. Nothing uses the pickup wiring.

[refugeefromcalif]

....Sorry, Double post.

[refugeefromcalif]

http://i.imgur.com/ytVvtnJ.gif?noredirect
One flew over the cuckoos nest, Ken Keasy's Classic book! (The film was good also). So many , (Now), great stars in it.
Michael Douglas's first production credit, (If I remember correctly).

George

[Bitsyncmaster]

I'm not 100% sure, but I don't believe that the flywheel has anything in it to actually trigger that sensor.

BTW I believe Rob is talking about the other pair of wires on the diagnostic connector, the Orange one in particular, which comes from the Lambda ECU for monitoring purposes. Nothing uses the pickup wiring.

My guess would be the sensor was planned to just read RPM from the gear teeth. I don't think they put any magnets on the flywheel.

[Delorean Industries]

Only two pick up holes are drilled in the back side of the flywheel for the sensor. This will not produce an even rpm signal for an ecu feed.