Forum;

First post here.

Electronically qualified, engaged vintage Volvo enthusiast and operator of the SW-EM site. As you may be aware, several Volvo models starting with the 1800 in '69 also had the D-Jet fitted, and I am revisiting it's installation/operation on my 1800ES as part of a recommissioning.

I have procured a Manifold Pressure Sensor Rebuild kit from Tangerine Racing near me in Connecticut and plan to rework a spare unit I have (which fails a vac leakdown test, so diaphragm is likely fatigued and holed as is typical). As an electronics specialist, my plan is to understand the function of the MPS in conjunction with the ECU in detail so that the post rebuilding functional tests can reestablish it is operating as it did when new, including calibration, and before this major work. I have read Mr. Anders' write-up on his site but have further questions.

I have been in contact with Mr. Anders before, when investigating the "Miss at Cruise" issue familiar to many D-Jet vehicle operators, and I need to once again talk electronic nitty-gritty with him about the MPS. I have tried the email I have for him (no response yet), as well as the telephone number (disco/non-functioning). If anyone has good current contact info, or can pass the word on and him to contact me, either through this forum or my e-mail, which he might still have, I thank those individuals in advance.

I am also aware of Dr D-Jet's site.

Cheers from the vintage Volvo world.

Ronk

Ronk - Welcome to 914World; I have always loved the early Volvos.

Welcome Ronk

I will just add one thing
The fuel has changed so much over 30-40 years
I’ve rebuilt about a half dozen MPS now
If you set an MPS to factory settings…. Those settings were established for a different blend of gasoline that is no longer available

So those settings create a lean situation to todays fuel blend

The only way to get a corrected setting to todays fuel (IMHumble opinion)
Is to use a wide band O2 gauge for AFR

And tune the MPS for the motor and fuel rather than factory settings

This is probably more important for air cooled motors that require the fuel charge to help cool the motor

But could still be causal to the hiccup you experience

Brant

While we have not seen Brad A around here much in the last several years he does leave his website up and its a goldmine of the info you seek. A lot of theory and specifics to 914s, so not much specific help to the Volvo platform but good broad D-Jet info. Study every word of this site.

Dr Djet as well - tremendous resource. Study every word of this site also.

I have several pieces of D-Jet test equipment and can rebuild and recalibrate your MPS [u]IF[\u] you can send me a known good unit to copy its calibration settings.
I only recalibrate an MPS if I build it. See my website link to my 914 harnesses below in my signature block for more info.

vacuum gauge and an afr + the tangerine kit is really the best way in my opinion (besides having Jeff do it I guess).

I would say tuning it yourself is still maybe best since you do really need to know how it is performing in your car with all its little potential differences, particularly if you rebuild the motor.