1988 740 GLE no power to fuel pump

pdphillippi · Post by **pdphillippi** » 06 Nov 2009, 05:43

I have a 1988 740 GLE and I'm having fuel/electrical problems. The car's engine stopped running last week I checked the fuel pump and found there is no electrical power getting to the pump. Any suggestions as to this electrical problem?

Post by **billofdurham** » 06 Nov 2009, 12:25

Welcome to Matthew's Volvo Site.

I have deleted your previous thread as this is a duplicate. Don't worry about posting the other thread in the wrong forum as the moderators will move anything that is out of place.

The first thing to check is the fuel pump relay. Unfortunately, the only positive way to test a relay is to put in a known good one. As there isn't another relay of that type in the car you could waste money buying one and then find it isn't the relay at fault.

Try this first. Switch on the ignition and give the relay a good hard flick with your finger. Sometimes this is enough to restart a relay which is beginning to die. If the engine now starts then the relay is the probable culprit and should be replaced.

This attachment shows the location of the relay on the relay board which is behind the front ashtray.

740 '88 Relay Board.pdf: (48.56 KiB) Downloaded 1319 times

Let us know how it goes.

Bill.

pdphillippi · Post by **pdphillippi** » 09 Nov 2009, 15:48

Hi Bill, Thanks for all your assistance it was as stated - it was the Fuel Pump Relay. We put a new one in and it started without hesitation. Again I appreciate it...pdp

Post by **billofdurham** » 10 Nov 2009, 12:16

You are welcome. Thank you for the update.

Bill.

pdphillippi · Post by **pdphillippi** » 04 Oct 2010, 18:01

Hi, I need a little assistance. Another problem came up with the Volvo stopping at a stop sign the car died and would not restart. I replaced the fuel pump relay with a new one still no power to the fuel pump. I replaced the fuel pump and fuel filter last November 2009. Does the power to the fuel pump run directly from the fuel pump relay or could their be a problem with the Radio Suppression Relay located on the radiator overflow tank or possible a problem with the coil? I thought maybe the fuel pump, even though it was fairly new, is faulty? Please help!

Post by **billofdurham** » 05 Oct 2010, 11:22

I would check the radio suppression relay because if it is faulty the car will not run. The name of the relay can be misleading but it is vital to the fuel system. In 1986 Volvo decided to isolate the fuel injector circuit because of some radio interference created by the pulsing circuit. The solution was to energize a relay (the radio suppression relay) with the pump/system relay feed instead of using it to power the injectors directly. The radio suppression relay then supplies the + power to the injectors.

On your year/model the engine cooling fan relay is the same part as the radio suppression relay and, usually, they are mounted next to each other on or near the coolant reservoir. Switch the connectors of the two relays. If the engine starts and the fan stops you have found the problem.

Bill.

pdphillippi · Post by **pdphillippi** » 17 Oct 2010, 13:49

Hi Bill, I really appreciate all your help regarding this no start issue on my Volvo. I have checked the Radio Suppression Relay and it appears to be working. I placed a charge to the fuel pump and it works fine. So I am sure it is an electrical problem. While checking the coil I observed the coil was receiving input power (electricity) but there was no electrical power going to the distributor. Would no power exiting the coil cause the fuel pump to not function? I am at a loss as to what it could be so I have pretty much come to the conclusion that I may have to replace parts as a process of elimination to find the problem. Any more thoughts as to what may be the primary problem. The coil has been on this 1988 Volvo as have all the other parts since I purchased the Volvo new when I was stationed in Europe. I went to Sweden and picked the car up in Göteborg on October 15, 1987, so I have been the soul owner and I know, or at least I think I know, all the parts that have been put on this Vehicle. It has been a super car! Again Thanks for your assistance....

Post by **billofdurham** » 17 Oct 2010, 16:06

Having had the car that long can we assume you like it?

A lack of output from the coil shouldn't stop the pump working. However, you need to find out why there is no output. Obviously you could just go out and buy a new coil, then go and buy something else and so on. Testing the coil is easy. The attached goes into greater detail than I hope you will need but start with the basic test to see if it is within spec on the resistance and we'll go from there.

740 ignition checks.pdf: (1.23 MiB) Downloaded 669 times

Bill.

pdphillippi · Post by **pdphillippi** » 22 Oct 2010, 14:43

Hi Bill, I checked every item I mentioned before to see if it was working the Radio Supp - Relay is OK, coil is OK and the Fuel Pump Relay is OK but there is still not power getting to the fuel pump! I have arranged to have the Volvo put on a computer to check out the problem so I hope this will locate the problem. I think this is a easy fix problem once it is located....

pdphillippi · Post by **pdphillippi** » 03 Dec 2010, 08:23

Hi Bill, I hauled my 1988 740 GLE Volvo to the repair shop and the mechanic put the car on a computer but according to the Mechanic the machine indicated that there were no Error Codes. He has been working on the car several days and has sent off for literature pertaining to the Volvo fuel and electrical system. He told me this Volvo was made in Europe for US specs but there are several slight differences in some of the parts. He is having problems locating the "CAM Mark" and the Mechanic seems to think the problem is in the Distributor! Do you know how the Mechanic might locate this device? Any assistance is appreciated. He contacted the Volvo dealership in Knoxville, Tennessee and was told where it should be but after checking he could not locate it. The car turns over just fine but somewhere between the electrical system and the fuel system there is connection problem. The fuel pump is working when a hot start is made. Again I really appreciate your help...