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I have a 1990 wagon that I bought with a warped head. I had the head resurfaced and re-installed the head. I also installed a 951 ECU. The car started immediately and ran smoothly. The next day, no start. I then replaced a bad in tank pump, and a leaking main pump. No start. I then replaced the CPS. I think it was good, but the insulation was broken. Rough start and horrible idle until warmed up. This morning, no start. I cleaned all fuses, verified function of air bypass valve. Rough start and horrible idle. I started to remove the throttle body for cleaning, and the accordion hose has oil in it. ??? How in the world does engine oil get in the accordion hose past the AMM??
Any help is appreciated.
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If you have been working on the intake system, check the plug to the mass air sensor.
The pins in the plug can get pushed back, causing poor running, in my case, the engine would not react to the throttle, but stumble instead.
If one or more of the pins look different, or pushed in, peel back the rubber boot and push it back in place.
Each pin has a tang to keep it in place - you can bend the tang a bit so that it remains in place. DO THIS VERY CAREFULLY,
The mass air sensor plug is one of the few plugs that get unplugged once in a while and its pins can come loose.
When my pins were in their proper place, I ran a magic marker line across the wires under the boot so I could see if any were moved. I would peel the boot back, plug in the mass air sensor, them push the boot back in place when everything looked OK.
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posted by
someone claiming to be Burco
on
Wed Jun 12 11:32 CST 2019 [ RELATED]
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The saga continues. Well, I had a delay due to rain, and a side job to replace the head gasket on my 93 classic wagon.
After replacing the temp sensor, and checking all wiring connections, the 1990 240 intermittantly will start normally, then next day have the aforementioned no start. I had to rob the dist cap and wires from it to get the 93 running while waiting for IPD to send plug wires. When I replaced the cap and wires, I now have a no fire condition.
I am trying now to run down the no spark condition, but following the Bentley procedures are very frustrating. I cant get the book readings, even on the properly running 93!
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The oil in the throttle body gets there via the PCV system, aka your flametrap. It is a result of piston ring blow by. Normal in high mileage Volvos, or those which have had poor oil service some time in their history. It isn't the cause of your no-starts, rough-starts, or poor idle.
--
Art Benstein near Baltimore
Test for Blow By
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Well, thanks for the info. I took a gamble, hoping to have a good car after the head resurfacing and gasket. I don't know if I am up to replacing the engine. I don't suppose new rings would do any good on the blow by?
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All IC engines have some sort of blow by, including new engines. That is why there is either an external catch can or a system to burn the oil vapors when the engine is running. It doesn't mean that your rings are shot or that the valve stem seals are worn down to nothing.
I thought it was interesting that the engine seems to run fine once it warms up. That statement caused me to point out the ECT sensor, which tells the computer to increase the amount of fuel when attempting a cold start.
You could also push the gas pedal down to the floor while starting, this turns off the injectors allowing for a 'flooded' engine to restart.
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Keeping it running is better than buying new
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Wow. That ECT sensor is NOT designed for easy access. Will eat my wheaties in the morning and get to it.
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Oil in the TB or Air tube is normal as Art said especially if the PO did not maintain the car.
Nobody said you need a new rings or a motor, what you need to do is catch up on neglected maintenance.
It has been suggested the ETC sensor is suspect that is a good place to start testing.
Read Art's last sentence again.
Dan
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Oil in the TB or Air tube is normal as Art said especially if the PO did not maintain the car.
It was a LOT of oil.
Nobody said you need a new rings or a motor, what you need to do is catch up on neglected maintenance.
That gives me hope. I am certainly committed.
I will test the ETC sensor next.
Read Art's last sentence again.
Which of Arts sentences? The blow by test?
I thank all of you for your help. It is obvious I am in deep water, and I really appreciate your help.
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"It was a LOT of oil. "
You've been around these cars, so I take it you're saying it was more than you've seen before. I've seen it collect in the AMM hose and make the outlet of the AMM wet, too. Can only suggest you clean it up thoroughly and check it again in a month, or a week, or whatever your sense of this indicates.
I've been a Volvo fan for only 20 years now, but one reason I'm delighted by these engines is I don't have to tear them apart even with 300K on them. Yes, I'm lucky to have mostly well-cared-for 2-owner cars, but every kind of American or Japanese car I owned before Volvos eventually burned oil, embarrassing blue-exhaust oil burning, long before making 200K or even 120K in some cases.
I did a re-ring on an 8-year-old Chevy Nova when I was young and dumb, rusting through the floor pan and fender at 65K miles. These Volvos are great, in that respect. I've never even heard a complaint about oil out the exhaust. Just oil vapor in the throttle body. If it ever gets untenable I'll look into a catch can.
Saw your note about OBD not working. Best approach on this forum is to start a thread with a specific topic, once you've found an issue you're sure has an accurate description. Say which ECU/ICU isn't reporting codes and how.
--
Art Benstein near Baltimore
By all means, marry. If you get a good wife, you'll become happy; if you get a bad one, you'll become a philosopher. - Socrates
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I had oil - a lot of oil - in the TB hose on one of my 740s. The oil broke down the rubber in the hose and it kinked in the middle and starved the intake of air. Idled and ran awful. I cleaned the flametrap, replaced the hose and then took it out on the nearby interstate. Went from zero to 90 without a hiccup.
So the OP might add "check the integrity of the oil soaked hose" to his to do list.
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You made me remember another consequence.
It might be a good idea to check the brake booster hose. A combination of oily PCV return and old motor mounts can weaken the hose right past the manifold nipple. It will collapse and make the braking effort feel several times normal.
Old cars, old parts, oily engine compartments...
--
Art Benstein near Baltimore
By all means, marry. If you get a good wife, you'll become happy; if you get a bad one, you'll become a philosopher. - Socrates
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Oil vapors from the PCV system condense in the intake and flow to the intake hose. By all means, clean the throttle body and the hose.
Verify the wiring to the ECT sensor is intact, then check the resistance to verify that the ECT sensor is functioning properly. Pull the spark plugs before starting the engine and clean them, I assume that they are quite dirty.
Check the idle air control valve, it my be stuck in the closed position.
--
Keeping it running is better than buying new
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Idle air control valve opens when 12V is applied. It is never closed
Throttle position sensor does not match Bentley ohm readings at all.
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New cars this old can have a lot of mischief in their histories. One good explanation for a TPS not measuring as a switch is that it is a potentiometer, used in LH3.1. Is yours an automatic? The LH3.1 came with M47 cars of that period. A 951 is not correct for LH3.1.
The IAC closes when the applied voltage has a small duty cycle (30%) but rests with its spring to allow some air for fail-safe idling.
Can't help on the ohmmeter measurements unless you get very specific and explain how you did them. Are you familiar with Mode 3 of the OBD?
--
Art Benstein near Baltimore
The secret of a good sermon is to have a good beginning and a good
ending; and to have the two as close together as possible. - George
Burns
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In trying to answer your question, I realized I attempted to test a 3.1 throttle sensor. My car is an automatic, therefore a 2.4. I performed an improper test.
The diagnostic function is not working. I was able to test the unit ( 241-8 in Bentley steps 1 thru 5 "To test diagnostic unit", It passed the tests but will not give a 1-1-1 code or perform the function 3 outputs test. I tinkered with it today, it started, ran rough until warm, then smoothed out.
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What is the ECT? I cleaned the throttle body, and flame trap, ( flame trap didnt need it ) It seemed to help, but it still runs very rough at start, but smoothes out when warmed up.
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The rough idle when cold could be a weak cylinder. Might do a compression check.
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ECT = engine coolant temp sensor
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Keeping it running is better than buying new
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