Greetings from the Netherlands

Good morning Dr-Djet Volkel and other enthusiasts!

I am Tjeerd form the netherlands. First of all i want to complement you on the fantastic job you did on gathering all the information of jetronic! I stumbled upon this beautiful website since i had difficulties with my car (a Volvo 145) to run on petrol and i wanted to fixs this. The car normally runs smooth on LPG but on petrol the car does not start at all.

At first the car did make a few strokes when swithing to petrol but then died again. I started with checking the fuel pressure and found that the pressure was around 5 bar so i adjusted it back to 2.0 - 2.1 bar. After this adjustment the car did not even make a few strokes any more so i suspect the injectors to be dirty and i will test them soon. I already measured the resistance and it showed 4.8 ohms on all four injectors. The documentation states they should have a resistance of 2.4 ohms but since i measured 4.8 ohms on all four injectors i suspect my ohm meter might be the culprit.

I also tested my MAP sensor for resistance and the primary coil measured 92 ohms. The secondary coil measured 385 ohms (measured with the same, possibly faulty, ohm-meter). but i think this is ok. To test the vacuum i gently sucked (not blow!) on the sensor to test for leakege since i do not have a proper vacuum pump. I did not feel any built up of vacuum unfortunatly and also heared a leakage noise at the front of the sensor. I think the membrame has teared since the car also runs on LPG and probably had a backfire somewhere along the line. The rivits and potting however are in perfect condition.


A small thought i had on preventing the sensors from being 'blown up' by backfire, is mounting a one way valve (or a normal valve) so the pressure is blocked in case of a backfire. Are there people with experience with this or would it result in faulty sensor measurements?

With kind regards,
Tjeerd

Hi Tjjerd,

a cordial welcome to you from Germany from Dr-DJet !

yes it sounds like your MAP sensors diaphragm is torn if you cannot pull any vacuum by sucking on it. A vacuum pump with pressure gauge would be better It does not cost more than 30€ from eBay. Look for vacuum testers or brake evacuators.like Bremsenentlüfter .

I am sorry that I have no experience on valves blocking backfire. But I do not think that would change D-Jetronic behaviour if the valve has enough air flow.