Hello friends new member. I have a 1990 240 dl. Ive had it for several years and i love it. Recently i just quit runnin and ive traced the problem to the fuel pums are not getting power. I changed the fuel pump relay and it didnt make a diffrence. What else could it be? I bypassed the relay and it starts fine but the main pump never shuts off. Please help!!!

 

Have you checked for power at the fuse box.The fuses get dirty and loose connection.Try checking for power there.You might want to remove all the fuses and clean the fuse box and install all the fuses again.

 

I did check all the fuses and noticed a little oxidation on a few of them but i cleaned them all up and i still have the problem. My brother and I worked on it all night last night. I was thinking it might be the fuel ecu? Ive read that they usually dont go out?? It only has 160K on it. I am getting two power sources to the relay and i hear a click when i turn the key but no power going to the pump.

 

I would check the wiring to the fuel pump then.If you hear the relay and have power coming out of the relay but no power at the pump check the wiring.

 

hello may i ask you a few more questions? I have checked the wiring to the fuel pump and the wirirng is fine. there is power gettting to the fuel pump relay but power isnt coming out. if i take the relay apart and manually push over a conection i then get powerto the pump. but like i said before i did buy a new relay from the dealer and instaled it and it isnt changing anything. its got me confussed. is there a way to check the fuel control module?

 

It sounds very confusing.Kinda got me baffled as well.I will see if I can find anymore info.

 

I changed the temp sensor and temp switch to see if it did anything and it didnt. I got curious about the intank fuel pump because i coundnt hear anything even when it was jumped. I took it out and it isnt working even when i jump it direct. Maybe this is the problem. Would that cause the main pump not to work as well?

 

I changed the intank fuel pump and it works, but the relay isnt enguaging the circut still. Now i think it might be the ECU but im not sure.

 

But still do you have power coming out of the relay?If the relay is clicking then the signal from the ECU is getting to the relay.When you turn the key on it should kick in for like 30 seconds then kick off.If the relay is clicking and no power coming out then the relay might still be bad.

 

The relay is clicking once (one side) when i turn the ignition. If i manualy push over the other side the pumps turn on. Also when i ground the skinny grean/blue wire on the relay harness the pumps work.

 

Let me try to find some more info and look somethings over and I will get back to you.

 

OK OK! I found out what the problem was it was the ECU i guess these go out all the time in the 89-90 240s. I bought a used one off ebay and it fired right up! TIP: the last three digits of the ECU will tell you if you have an ECu that is know to go out. 561 is a bad ECU they were put in 89-90s if you can buy a 951 ecu these were put in the 92-93 240s and are alot better and rarely go out. Hey Tech Thanks so much for your help!

 

Now problem anytime I try to help when I can.