Hi all,

I have a stock 1988 740 turbo with lh 2.2, b230ft, with around 240,000 miles. Tow truck just dropped it off for me.

The car feels like it is running on 3 cylinders and drove and ran very similarly to my old Camaro when I blew its head gasket. I was on the highway for about ten miles then the car started surging and running really rough. I pulled off the freeway and the car would idle at around 750 rpm but didn't like to accelerate, stumbled, and ran very poorly.

Tommorow I will check the oil and coolant reservoir for contamination, rent a compression tester, and go through things like cap, rotor, spark plug wire resistance. But I would defiantly appreciate any ideas or suggestions on what else to check or look for.

Also earlier today I bridged the positive terminal in my alternator and made a big spark. Is it possible that this could have fried something?

Thank you for reading and thank you for any ideas or suggestions you may have.

Moustacio,

If you think that the problem may be your #2 injector not getting a pulse, you can rent a test light tool from O'Reilly Auto Parts, if you have one in your area. Its called a "noid" light, although the people at the counter may not have a clue what you are talking about if you call it that. Just refer to it as a fuel injector test light kit...you'll probably get a better response.

The kit consists of small test lights that have two prongs that you plug into your injector connector once you pull the connector from the actual injector itself. If your connector is receiving a "pulse" or "signal" the light will light rhythmically in time with what the pulse should be that is going to the injector. If it doesn't light...well the injector isn't getting a pulse.

You make ask why you can't just hook up a regular test light and get the same results. The answer is because test lights have an resistance that is too high to allow the light to come on for a regular test light. The resistance is low enough on the "noid" light to allow the signal to come through.

Hopefully, this will help you out if you haven't already resolved your problem.

Here's the link for the rental part from O'Reilly:

http://www.oreillyauto.com/site/c/detail/PFM0/W89500.oap?ck=Search_fuel+injector+test+light_-1_-1&keyword=fuel+injector+test+light

Good luck. Let us know if you have the issue resolved.

Hi and thank you much for the information.

I have resolved the problem, see above post, it turned out to be a bad wiring connection at the ballast resistor.

Again thank you for your response.

Solved the problem, hopefully.

I resoldered the wires connecting to the ballast resistor and it runs on all 4 cylinders again.

I'm pretty sure that was the issue, I'm just hoping it's not some intermittent fault. Also, I'm going to try and find a replacement at the boneyard.

Thank you much for everyone's suggestions and help I very much appreciate it and hope I can return the favor in the future. Thanks everyone.

Had them symptoms when my AMM went south. I could rev in neutral, but in gear, bogged down, stumbled etc.
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Hi, thank you for the response.

I didn't think about that, do you think a cleaning might help? Or do you think it's possible that I fried the amm out when I bridged the alternator?

I will pull the connector for the amm tomorrow to see if the car runs any differently.

Also, when I rev in neutral I still feel the same roughness like it's not running on all cylinders, but I only revved to less than around 2,500 rpm.

Thanks again for the suggestion, I much appreciate it.

Don't think cleaning will help. Quick check pull your dip stick and see if any water droplets on on it. Really though. 240k on a turbo and never a head gasket. That's pretty good.
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Hi and thank you again.

All I have been able to do today is check that there is no oil in the coolant and I'm pretty sure there is no coolant in the oil. Pulled the connector for the amm and the car ran differently so I'm thinking that it's ok. And I pulled the spark plugs.

Numbers 1,3,4 are black,oily, smell like gas and #2 is white/grey.

Do you think it's possible that #2 is not getting fuel? There is no smell of fuel on #2.

Thank you again and I'm probably going to pull the cap and rotor to check those out until I can have my girlfriend crank while I check for spark when she gets home.

You should be able to feel by touch that the injector is clicking--or use a long screwdriver, socket extension or actual stethoscope placed against the injector and your ear to hear its operation. That being said -- a light white/gray appearance would be more normal than black/oily. -- Dave

Ok so I'm pretty sure I am running on 3 cylinders.

I put the plugs back in, started it up, and pulled the plug wires one by one. Pulling the wire for cylinder #2 had no effect on the way the engine ran while all other wires did. And cylinder #2 was the spark plug that had no fuel smell on it. Also, all wires made spark when I touched them to the heat shield.

Not sure what is wrong there but I think that cylinder #2 is not getting fuel. I tried to feel the injectors for clicking while the car was running but couldn't feel the click on any of the injectors, I will try to listen with a screwdriver though.

Is it reasonable to think that my ballast resister is not functioning properly? For a long time I have been running with two of the wires connecting to the ballast resistor soldered on there.

Any further help is much appreciated.

I listened to the injectors for clicking and didn't hear the #2 injector.

Then I jiggled the ballast resistor wire, where I have the wire soldered to the ballast resistor, started the car and i think it ran normally for a minute until it ran on 3 cylinders again. The solder joints are not great.

Could a faulty connection at the ballast resistor cause the injector not the fire? Or should I be looking elsewhere.

Also I have a multimeter is there any way to check for voltage at the injector's wiring connector?

Thanks again

It is possible that poor connection at the ballast resistor is causing the problem. Scroll down to LH-Jetronic 2.2, B230FT..Item 376 is your ballast resistor.

http://www.autoelectric.ru/auto/volvo/740/1989/740-89.htm
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