Hi folks: I am new to the forum, and have a problem with my 1988 240 DL wagon.

The car starts, runs for a few seconds, then stalls. It seems to me to be a fuel related problem. Both fuel pumps are working, and I just replaced the fuel pressure regulator - but still the same problem.

The engine will stay running when the fuel return to the tank is plugged. (this symptom let me to replace the pressure regulator)

Engine specifics: B230F engine
Fuel system specifics: LH 2.2 Jetronic

Thanks for any and all advice,
Andy Hall
Lynn, MA

 

Try cleaning the throttle body really good and the idle motor.

 

Thanks for the quick reply. I will try what you suggested and report my results.

One thing that makes me skeptical of the idle motor is the fact that just before the engine dies, you cannot "save"it by opening the throttle. It sometimes sputters a bit, but does not continue to run.

But, I wil certainly check it out. Thanks.

Andy Hall

 

I will be waiting to hear how you make out.

 

Hello group: Still no-go with my 240.

I removed and thoroughly cleaned throttle body, and checked operation of idle solenoid. (checks out functional)

The car will start, then after a few seconds, die.

The only way I can get it to run is to increase fuel pressure by blocking the fuel return.

Is there a proceedure to check if ECU is turning on the fuel injectors properly?

Thanks
Andy Hall

 

If it starts then the injectors are getting fired properly.
Try unplugging the mass flow sensor and start it and see if it runs any better.

 

I unplugged the mass flow sensor, and the car would not start.

After plugging it back in, It still will not start at all.

I seem to be loosing ground.

any advice appretiated.
Andy

 

Maybe you have a bad control module the car should have gone into limp home mode and ran.

 

Still the same problem with my 240.
Engine will start, then die after 2 seconds.
This first occured after driving for an hour with no trouble. Car was then shut off for 5 minutes, and could not be restarted.

I've found: Fuel pressure -ok
Good spark (using spark tester)
Throttle body clean and switches work
Mass air meter- resistance test ok
Idle control valve - ok
Coolant temperature sensor - ok


Any suggestions before i shell out for a new control unit?

Thanks,
Andy Hall

 

I can't think of anything else but try to find the control module used first.

 

My symptoms are now slightly different. With the mass air sensor plugged in, the engine starts, then dies after 2 seconds (the same symptoms as before).

If I unplug the mass air sensor, the car runs. Could this be the "limp home mode" from one of the earlier posts?

This confuses me, because the mass air sensor tests ok.

Thanks,
Andy Hall

 

If the problem is related to low fuel volume or pressure, it could be a clogged fuel filter, clogged in tank pump screen, weak fuel pumps or bad FPR ( even a new one). If it now points to a bad AMM, I would be suspicious of other things. I would check, remove, clean and seal all of the grounds in the engine compartment. Look closely at the ends where they connect/crimp to the wires for signs of corrosion, especially all of the ones for the fuel injection system that are on top of the intake manifold. I would then check for any source of extra air entering upstream from the AMM, such as bad vacuum lines, intake snorkel holes/splits, throttle body gasket and intake manifold gasket. If that did not solve it, then the fuel pumps would need to a checked by doing a current draw test and then a volume test done at the fuel rail to confirm the condition of the FPR. If all that checks out, then it is time to get out the Digital Multi Meter and start checking the harness to the ECU. A lot of AMM's are prematurely trashed , when it is usually something else that is the underlying cause.

 

I have remade all the ground connections. (none of them looked suspect)

I have checked the wiring pin-to-pin between the mass air sensor and the ECU - all ok

Resistance measurement between pins 2 & 3 on the mass air sensor measures 2.2 ohms versus the Hanes Manual reference of 3.5 to 4 ohms. Would this cause my problem? (don't quite get how the resistance could drop)

How about any leads on a schematic for the guts of the mass air sensor?

Thanks for tolerating my endless questions.

Andy Hall.

 

Im not sure of the spec's hopefully someone will be able to help you with that.

 

There are not many reliable ways to test an AMM. The 007 AMM's on the 88's do not really have anything to repair on the inside, just a variable pot hooked to a chip that is encased in gel with feeds to the ECU, platinum wire etc. Bentley's manual ( well worth the $40, throw the Hayne's away) only has a test of the variable potentiometer ( the CO adjustment screw under the tamper proof plug),should be 0-1000 ohm between terminals 2 (green-yellow) and 6 (yellow). If you have the plug removed, turn the adjuster back and forth and see if it responds, just put back to original measurement when finished. You can also test terminal 3 ( white/red) for voltage by peeling back the rubber boot and back probing with the key turned to K II, on but not running. It should be 1.2 v or better, with 1.3 or 1.4v being preferred.
The traditional method of unplugging and checking if the car idles better is dependant on everything else that would affect engine management being up to snuff. No air leaks, no lazy or dead O2 sensor, correct fuel volume and pressure at the rail, no dirty or clogged injectors, TPS good and adjusted , coolant temp and knock sensors good and all wiring 100%.
On your original question about checking to see if the ECU is 'communicating' with the injectors, you can obtain a Noid light ( about $4) at a good auto parts supply house. Ask for one that will fit the Bosch PFI or multi port systems. Unplug one the injectors, plug in the noid light then place where you can see it from the drivers seat, and start the car. If all is well, it will light every time it received an impulse from the ECU.
If the car has not had one in the last 4-5 years, I would go ahead and replace the intake manifold gasket. They like to sag and leak at the bottom of the runners, and it is a fairly easy and cheap fix so you can rule that one out. Also while the manifold is pulled back, you have easy access to all of the goodies underneath, flame trap/pvc box, coolant temp and knock sensors and wiring etc ,to service or just to get a good look.

 

Success!
a "new" AMM fixed it.
I measured the terminal 3 voltage as you suggested at 1.13 volts and decided to take a chance on an AMM found on an '85 found at a local junk yard.
When installed, it measured 1.25 volts and the car works!
This measurement seems to be a good test.

Many thanks for all your fast and helpful responces. It was a good learning experience.

Thanks again,
Andy Hall
Lynn, MA

 

Im glad you got it running great again!!

 

Hey , Can you please give me more information of AMM or part number as I am looking to find same part for my cat, Thank.

 

15 year old thread.

what year/model car do you have, and is it a US model, or world market car ?, there are different AMM's for different versions. the Bosch and Volvo PN's should be visible right on top of the AMM aka MAF in your air intake path

 

Hey thanks for your reply! Car is 1984 244 DL with 2.3 motor and its made in Sweden