92 240 still no start

[xDread92x]

Hey All,

I’ve been on here the last few months about my wagons no start. I’ve replaced a lot in the fuel system so far but I’m unsure if it’s even a fuel problem anymore. It went from rough hot start ups to not starting at all now. I’ve replaced fuel relay, fuel pressure reg., in tank pump, main pump, cold start injector, O2 sensor, and AMM. Today I took the hose off from back of main pump and lots of fuel came out while starting. Relay is clicking and main pump is buzzing.

What I did find when replacing in tank pump was the sock had been off. When I replaced the old main pump there was crud in the pump. Could junk have passed through the old fuel filter and affected the upper lines or injectors possibly? I was told before a bad injector wouldn’t cause no starts?

Could it be something else non fuel related?

Thanks

[Hacksaw116]

Please enlighten us further. Turbo or NA? You check plugs, wires, cap and rotor? Got spark??

[intothelabyrinth]

Rough hot starts sound like coolant temp sensor. Check values at the ECU connection.

[dl242gt]

More crud than was supposed to went into your intank pump and main pump. Some amount of tiny particles can make it all the way to the injectors. A good injector cleaning may help. If the spray pattern decays too far then it's just liquid gas fouling out the plug and sitting in the cylinder.

[xDread92x]

The spark plugs when taken out over a month ago looked fine. Distributor cap and rotor are clean.

How can I test injectors? Just remove from intake and see how they spray while cranking? Non turbo, LH 2.4

[Otto Mattik]

Originally Posted by xDread92x

I’ve replaced fuel relay, fuel pressure reg., in tank pump, main pump, cold start injector, O2 sensor, and AMM.

What I did find when replacing in tank pump was the sock had been off. When I replaced the old main pump there was crud in the pump. Could junk have passed through the old fuel filter and affected the upper lines or injectors possibly? I was told before a bad injector wouldn’t cause no starts?

Could it be something else non fuel related?

a) Cold start valve ? (I don't think 2.4 has cold start valve, I have 2 92's neither have it)
b) o2 won't cause a no start, but if not working it will not send correct info to computer
c) Was something wrong with your old AMM ?


Have you ruled out ignition issues ?

a) You can test Power Stage (ignition module)
b) CPS(crank position Sensor) can cause headaches, how does the wiring look ?
c) Do you have consistent spark ?

[ZVOLV]

Buy tools instead of throwing parts darts at the problem.

Click my sig. No start diag.

No start should be easy to diag.

[xDread92x]

Hey guys. Im checking for spark tomorrow and going to see what the outcome is. One thing I haven't checked is the crankshaft position sensor. Im hoping to get some lead way on this tomorrow. I had intentions of this before but called it off due to people saying its a tough replacement. I could also check fuel from the main line and see if its coming through. I know fuel is getting from the tank to the main pump and filter. After the filter I am unsure.

****Sorry about earlier post I didn't mean to say cold start injector I meant to say coolant temp sensor****

No codes except 132 on fuel saying battery voltage low or something. I think it may be from the car sitting the last two months.

[ZVOLV]

There are a few common points of failure, but I advocate proper diagnosis. Being a pro, I get in trouble with a few different parties if I guess wrong.

Check for spark first. If no spark suspect the powerstage
Do diag on it next. Wiggle the crank sensor wiring while a buddy cranks.

[sbabbs]

You can pull the injectors and put each in a plastic or glass bottle to check spray while still hooked up to rail and in the car. Unplug coil wire while doing that. Extra safe way no gas spraying on motor and no spark..

This is the super secret pro trick that those pro's won't tell you. They say other things like sillyscope it. Ha.

Check your fuel pressure regulator at the end of the fuel rail. Pull the vacuum line off it and see if any gas in that line. That would mean it's bad.

[xDread92x]

Hey All,

The problem was the crankshaft position sensor. I had one on a spare 240 and it was miraculously in amazing condition when i took it off. Swapped em and she cranked right up. Running great now! The one that was bad had lost its insulation completely and wires were exposed near the base.

[ZVOLV]

Nice. It's a very common point of failure on these cars. One way to test would be a resistance test across the two signal wire pins and then wiggle the wiring and see if the reading changes.

[ZVOLV]

I just got my 1991 740 on the road after cylinder head removal, turbo and cam upgrade, new seals, etc. Road test was good until it started sputtering on the freeway.
I drove it to the shop immediately and parked it. I left it running and went under the hood and wiggle tested the crank sensor wired and it stalled and now it won't start. New crank sensor is on the way!!

[xDread92x]

Haha yea man!

It’s going to run so much better. Even starting it and how it acts when shutting off will feel more smooth and balanced.