740 wont start

heitzman · Post by **heitzman** » 07 Jul 2013, 13:30

Hi everyone I am new to this forum. I have a problem with my 740 not starting, it has 200,000+ and it ran perfect before I parked it for a week. I ran the codes and it gave me a code to the CPS so I replaced it. This did not get the car started so I checked the fuel relay and I am getting two clicks out of it when I turn the key. I checked the fuel rail and it just gets a trickle for a couple of seconds when I turn the key and when I try to start it no fuel to the rail. I jumped the fuel relay and I have a steady flow of fuel the rail but no start. I am getting spark to the front plug. The parts I have replaced are Crank sensor, Fuel pump, Fuel filter and Fuel pressure reg. I am stumped please help and thank you.

russellengineering · Post by **russellengineering** » 07 Jul 2013, 22:00

Hi Heitzman,

I am not the greatest at this like some of the others, but thought I would give it a shot.

You said you jumped the fuel relay and got fuel pumping to the rail. Did this mean that you think the fuel relay is good? Do you have a wet plug, or dry plug when you checked the plugs? If you have a dry plug, the fuel relay is a suspect to verify and replace. You also said you replaced the fuel pump, but your car has a prepump in the tank, and a main pump under your seat. A bad prepump will cause a no start or rough running, even if the main pump is good. The main pump cannot suck the gas out of the tank, especially if the level is down. The prepump cannot deliver fuel to the rail by itself.

Will the car ignite at all, or is it stone cold cranking? You said you had a spark, so are you getting any combustion at all? The ignition circuit has the CPS which you identified and replaced, the Radio Suppression Relay, power stage and distributor. They all can go bad and make intermittent to no-start problems.

Look forward to hearing back!

Dave

heitzman · Post by **heitzman** » 08 Jul 2013, 04:29

I can not find another pump on the car, would it be in front of the filter or back? I am getting fuel when I jump the relay but with out the jump just a trickle. I have swoped both radio suppression relays and still nothing. The car as of now just cranks. I pulled the front plug and I have a wet plug. I am trying to get a noid light because I think there is something going on with the pulse to the injectors, I have voltage to the injectors but I don't know about pulse. I am beginning to believe it has something to do with the distributor or power stage, how do you test for these and which one is more likely to fail? Thanks Dave

heitzman · Post by **heitzman** » 08 Jul 2013, 04:36

I have no activity on the tach when cranking the engine. Does this help anything?

lummert · Post by **lummert** » 08 Jul 2013, 12:22

No tach activity may indicate a problem crank position sensor.

JerryC · Post by **JerryC** » 11 Jul 2013, 13:26

What year? Bosch or Regina? What code exactly?
OP said 'cps' so this tends to indicate lh2.4 or Regina, but certainty would be helpful.
No tach indicates no spark/no cps, so maybe the new one is no good, or there is a problem with the tone ring, which has happened.
Of various possibilities, the cps and power stage are the most frequent.

Re: pump/s, year tells the tale. Regina has one intank, Bosch has two, one next to filter, til 95 which has one intank.
Super rare but happened to a friend last week; the cam gear pin failed and the gear spun. At rest it'd turn, but it was way out of time.

heitzman · Post by **heitzman** » 13 Jul 2013, 20:27

Regina system, one in the tank. UPDATE: No tach activity, No constant fuel pressure at the rail, Noid light test showed a pulse at all injectors and I went ahead and replaced the cap and rotor when I inspected it. Please help. Injection Control Module???

JerryC · Post by **JerryC** » 13 Jul 2013, 21:09

As above, what code exactly?
I have never seen a post about a bad Regina ECU, on any board. Don't fire the parts cannon.
Regina does suffer from corrosion in the coil; apparently there are two contacts inside that can be polished.
"No constant fuel pressure at the rail" How was this arrived at?
It's not hard to pull an injector, point it at a towel or something, and turn the key and see if it sprays. Have someone help you. It won't spray long as the pump only runs briefly without the car running, but it should be enough to tell.
Don't start a fire of course, disconnect the coil.
Have you pulled the plugs to see if they get wet? Based on what said so far there is an ignition problem.

heitzman · Post by **heitzman** » 14 Jul 2013, 09:14

I don't recall what the exact code was at this time, I am so frustrated at this point I am ready to give up, but I researched it at the time and it was the CPS. I believe the parts cannon has already fired, I don't believe in doing this but I want to get it started. I can jump the Fuel relay and I have pressure no start, I can put the relay back in and have just a dribble of fuel come out of the line. When I disconnect the fuel line from the rail, gas does not spray anywhere so that is why I think I have no fuel pressure. Yes I have pulled the plugs and they do smell of gas. Injection control module? Is this the unit that sits with the coil in the engine compartment on the drivers side. Does this car have what is called the Power stage, if so where is it and how do you test it. Thank you