|
|
|
"he crank position sensor wire where it enters the crank sensor shell"
"loose FI ground connection"
These are possible reasons my car is ailing, but I can't understand the directions they gave for locating the crank position sensor wire, and I have no idea where the FI ground connection is.
Can someone tell me in very simple terms how to find these? I have been to my mechanic three times and still have the problem, so I would like to research a little on my own before heading back in.
|
|
-
|
|
|
RSTARKIE showed the Injector grounds. In addition, there should be a braided wire from one of the Acorn Nuts on the Valve Cover to a bolt on the Firewall.
--
'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me http://home.no.net/ebrox/Tony's%20cars.htm
|
|
-
|
|
In addition, there should be a braided wire from one of the Acorn Nuts on the Valve Cover to a bolt on the Firewall.
I believe that braid (two on my 940) is only to reduce radio noise from the ignition. I don't believe it affects the motor in any way, which is already grounded by the battery cable.
NOTE: A bad battery ground has been known to "smoke" that valve cover ground when the starter current looks for a way back to the battery. As Don Foster once said here,
"Those electrons have to get back for revolting."
--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.
|
|
-
|
|
|
Not positive but I think The Motor Mounts isolate the Battery ground from the Chassis.
--
'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me http://home.no.net/ebrox/Tony's%20cars.htm
|
|
-
|
|
|
The battery negative terminal has a double cable, one goes to the inner fender body metal, and the other to the engine (PS pump bracket maybe?). The car will run fine without those little braids from the valve cover.
--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.
|
|
-
-
|
|
|
Thank you for the picture! Thanks everyone for quick responses, but since I don't know what most of the OTHER parts are that you mention, I really need the diagram.
You asked about symptoms. My car stalls a lot, especially at turns and stopping. After a turn or going uphill, I can press on the gas and nothing happens, then if I sort of pulse the gas pedal a little it will come back to life. If I haven't driven it for a day or so, it can be very hard to get it going in the morning--several starts, then restarting at each stop. There is a lot of spitting and inconsistent idling--if I stop for a while, it goes from normal to rough and then I stall. My mechanic adjusted the O2 sensor and it seemed better, then started acting up again. He replaced the air mass meter--same thing. He replaced the main fuel pump--same thing. Before returning, I'd like to have a clue so I don't end up replacing the entire car.
|
|
-
|
|
|
While the symptoms are not what I would consider classic fuel injection relay problems you have to consider it. They are a known weak link in the system and many times a replacement solves the problem.
The circuit board in Bosch (brand) relays have a tendency for the solder joints to crack and give intermittent contact. The cheapest way to solve this problem is to remove the relay, open it up, and resolder the joints. The easiest way to get around that is to purchase a new relay and install it.
Your relay tray is under the ashtray of your car. The FAQ's discuss the method to remove the ashtray and the small storage bin above it to make access to the relay tray easier. The FAQ's are found by using the drop down menu on the upper right side of this page. This diagram shows the location of the relay on the extreme left hand side of the middle row.
Your mechanic does not seem to be up to speed on the care and nuturing of your Volvo. I think you can do better, especially in the Pacific Northwest. You might make a new posting with a subject of something like "Need a good Volvo mechanic in Kent, WA"
Personally I would chase the idea of a new fuel injection relay if you have not addressed it in the time you have owned the car. Good luck.
Randy
|
|
-
|
|
|
http://www.brickboard.com/FAQ/700-900/EnginePerformanceSymptoms.htm
Skip down to the part about stalling. It walks you thru the diag procedure. PS your mechanic doesnt seem to have a clue and is throwing parts at the problem. Usually only hackers like me throw parts at a problem..:)
|
|
-
|
|
|
There is NO crankshaft position sensor on an 88.
FI ground points include the bolts on the intake manifold with several black or brown wires going to each, and one or more near the ECU, behind the passenger side kick panel. There may be others I'm not aware of. Also make sure the braided ground straps from the two rear cam cover bolts to the firewall are in place and their connections are clean.
Check the wires to the Hall effect sensor in the distributor. It's what your car has instead of a crankshaft position sensor. There is a plastic connector block on the bottom of the distributor that often deteriorates from exposure to heat and oil.
Also check the Radio Interference Suppression Relay. Despite its name, it provides power to the injectors. Open the relay and closely examine the solder joints. They are often weak, and prone to deterioration with age. This is often the cause of intermittent running problems. If bad, the connections can be resoldered. There is also a possibility that the terminals in the connector block for this relay can be pushed out of position and fail make proper contact with the pins on the relay.
|
|
-
|
|
|
Crank position sensors came into the Volvo line (at least in the US) with the 1989 model year. So your 1988 does not have one. It uses a hall sensor switch in the distributor.
I believe your fuel injection grounds are the ones that are bolted to the intake manifold. There are several wires grounded on the manifold in at least two places. I will see if I can find an image to post to direct you to them.
What are the symptoms of the problem you are experiencing?
Randy
|
|
-
|
|
No US market 1988 740s had crank position sensors.
The fuel injectors ground through the ECU.
There are several fuel injection grounds on the intake manifold. Check the 10mm head bolts, with wires under them, on the intake manifold. Make sure the bolts are tight, and the wires are firm in the crimp fittings.
--
john
|
|
|
|
|
