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I've had a string of issues with my '89 240 that may or may not be connected, I'll start with current symptoms first and work backwards.
The car is currently very difficult to start and will not idle, needs the gas pedal pushed to keep running. It also backfires infrequently. My wife drove it about 40 miles and went through a half a tank of gas! My wife said that if she downshifted (stick) and put the pedal to the floor then it would go, basically operate normal. She said that it lacked a lot of power on the hills.
The exhaust smells rich and the underhood smells of raw gas but I cannot find the source.
Previously the car was running rich (I could smell it in the exhaust) but nowhere near half a tank per 40 miles.
I recently replaced the fuel pressure regulator as I was having a misfire/hesitation issue that the new FPR almost completely resolved but there was still a slight hesitation.
I also have a hard time filling the gas tank, it seems the vent is clogged.
The area between the head and crankcase is wet all the way around which made me think I had a blown head gasket but I cannot find any other evidence; no oil in the coolant, no coolant in the oil, not losing any coolant, no bubbles in the coolant, no pressurized coolant hose.
Are these all related somehow?
When my wife pulled into the garage after the 40 mile trip the underhood smelled of burning/melting wax, I have no idea what that might be. I have never smelled this type of smell on a car before.
The vacuum side of my FPR reeked of gas (the one I just replaced!).
So here's what I've done; replaced AMM with known good sensor- no change, disconnected cold start injector- no change, swapped FPR- no change, checked timing belt (recently replaced) no slack, crank position sensor was recently replaced as was the fuel pump and filter. Plugs/wires/cap/rotor are all relatively new and in good condition.
And there's no codes! Not one single code, how is that possible?
Return line clogged to the tank backing up into the FPR and forcing a rich condition??? I have not yet tried disconnecting it.
I don't think a bad oxygen sensor can cause the engine to suck down half a tank in 40 miles but I'll be getting a new one anyhow (I'm trying to make this a reliable vehicle).
Any ideas what I should try?
Thanks!
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Well I don't know what to think but it's fixed.
I decided to swap back in my old MAFS and voila...
The exhaust has a small leak in the downpipe so that accounted for the noise.
In the future I'll keep in mind that even a $250 sensor from a reputable place can be faulty.
What really fixed it? I suppose it must have been the O2 sensor.
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Running extremely rich, will not idle ]
Posted by machine man on Wed Nov 30 12:00 CST 2011 > V “So, if the CSI was dumping gas in then the engine should run after swapping injectors.”
Why do you think that changing the cylinder injectors will fix a leaking CSI injector?
What shape is the AMM on this car? I forget if I read about how it runs unplugged. It will start in limp mode but will not have power above 20 mph.
Just something to think about or I have from my end, like my other posts.
Phil
I am glad to hear you got it running. Just by any chance, could we have had some sort of mental telepathy? On the other hand, did you read my post and think about?
Those AMM can be tricky devils!
Phil
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Congratulations, now change the oil and filter. Get another spare AMM.
Dan
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Has anyone considered that this may be a bad ECU? When mine went bad, the car ran very rich and set no codes.
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Amen! I have an extra ECU, this is just frustrating.
New O2 sensor and it still runs very very rich.
The exhaust does not seem clogged as there is plenty of black smoke exiting it.
It backfires, kicks hard but runs smoother at high RPM.
I see it has finally set some codes!
By the way the cold start injector is removed from the manifold so the injectors must be the culprit.
Or whatever is telling the to spray so much fuel.
I also rechecked the timing and it is definately timed correctly.
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I disconnected the fuel line to the cold start injector and started it up. It is still runinng rough and the line dumped gas VERY fast. I don't have the right tools to pull the injector.
Should the line to the cold start injector be spewing gas at 51 degrees?
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I am sorry you miss understood me.
I wanted you to pull the injector as a complete unit and then plugged the open space so the engine could run without a massive air leak.
This way you can see if the injector is spewing gas or leaking all the time or not. The line always has fuel from the rail and the all the injectors.
Phil
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Given the lack of power you may also want to check the alignment of the timing sprockets the belt, may have slipped a tooth.
Dan
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I just re-timed it to be sure. No immediate improvement.
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I considered that but I don't see how the engine could perform so well when floored, nor would it explain the rich condition. I'll be checking it just to make sure though.
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You talked about checking the oil. Does it smell like gasoline dilution?
Are all the plugs showing soot? They must be or you could narrow it down to only one injector by now.
You said you disconnected the cold start injector. You must mean electrically but it is still has fuel pressure on it.
It might be leaking so bad that it would make it hard to start; run rich and make the oil leakage smell like the dickens. Dickens is somewhere between a skunk and tar! Excess fuel creates more heat in the exhaust and the whole place gets hotter under there. It will probably damage the 0-2 sensor if it goes on too long.
I would pull the injector out and plug the hole in the manifold and see if that helps. After the car gets just a little warm that injector is not used. The computer adjusts the time on pulse width on all the other injectors to control richness.
That is my best guess from the armchair.
Phil
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I drained the oil and it smells like the dickens. Plenty of gas in the oil, hope nothong got ruined.
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You said you drained the oil and it has dilution with gas. Now we are getting somewhere.
Gas can only get to the oil from the fuel rail. This is through the injectors we have discussed, one for each cylinder and the cold start injector.
Another way is through the diaphragm of the fuel pressure regulator. It goes straight into the intake manifold via the rubber vacuum hose.
You asked how I could check it without buying another. You can try to draw a circle without a guide but it is not as good.
Go to a P&P and find another one. Check it with your tongue. Suck and plug it then hold it for a while. You should not be able to suck air through the gas side, as it has to hold rest pressure with out any vacuum. However, shopping with a hand vacuum pump with a gage, taste better.
The hose on your car can have a very faint odor of oil or gas fumes because vapors float around during shut down which could be considered normal. If you put a fresh hose on it and use a hand held vacuum pump or a food saver machine you can test it. If you care to suck on it, your tongue may pick the taste of vapor and that would mean the regulator is bad, as the taste.
I would pull all the injectors and run the pumps (engine off) by jumping the left side of fuses 4 and 6 with a jumper wire or a paper clip as Art does on his, cleanflametrap.com site.
The injectors should not leak. Since you said all the plugs were sooty, I am thinking the cold start and the FPR because they act by themselves, which would flood all the plugs. The cold start injector will pool gas into the manifold. You said something about pushing the pedal down all the way, so it can get lots of air. It takes only one of the other four injectors to add gas to the oil, over a period.
How are the coolant/head sensor and wires? As this could be a controlled flooding (cold engine) situation too.
Phil
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I swapped injectors and now it isn't starting. Double checked all my connections and all looks good.
Is there a prime I need to do? I cranked for quite a while.
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Yes, you are on it. I left you with pulling the CSI as it has the greatest potential to flood all the plugs.
Some how gas is getting into the top of that engine and once it pools there it takes awhile for it to disappear.
You say you swapped injectors. Does that mean between cylinders or another set entirely?
I wonder if we are dealing with a bad wiring harness that goes down under the manifold now. I wonder if a wire is bad and was grounding the injectors, which would make the open all the time or as the wire(s) dictated. A set of “node” lights would help spot what is working or not, while wiggling the wires, while it was cranking, for the ECU to light them up. A solid on light would nail it down to a bad wiring or ECU.
Gas has to be getting into the engine somehow and is the ultimate question.
I also wanted you to consider the coolant sensor wiring for the ECU as it affects the mixture for temperature changes of the engine. I wish I could remember if these LH systems have a thermal interrupter on the engine block to override the CSI operation when the engine is warm as it may be defective. A 1989 car is beyond my thinking tonight.
Diagnostics methods...boy, we need a hand full of those!
If you laid, all of the injectors out of their holes and electrically unplug them. Observe them for leakage with the pumps running with number four and six fuses jumped.
After that, take the jumper off the fuses and remove fuse six to kill the main pump from operating.
If you did not find leakage, you could hook up only the CSI and see it sprays out the rest pressure when cranked, if it does, leave it unplugged for sure! Then investigate why it sprayed later. It may depend on how cold the engine was.
Then I would continue to crank the engine with the injectors still out, unplugged and throttle wide open. It will help evaporate excess fuel in the intake manifold and fire the plugs dry.
I do not know it this is workable but it is think-about-able.
Plug up one injector at a time or all, your choice. Turn the key to number two running position and check each injector to see if by chance it clicks on. It will take two to do this I would think. I think we could find out if ANY power is turning on an injector by itself through a bad wiring harness. Wiggle and pull at all the wires robustly and listen for breaks or connections to an injector.
After this troubleshooting method put all the fuses back in and the injectors with good seals. The engine cylinders should be dry by now. Then see what gives!
I shall be curious to say the least.
Phil
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I swapped all injectors with a spare set.
When I pulled the old injectors they were not soaking wet and did not appear to be leaking.
I was not able to pull the CSI, seems like I need to modify an allen wrench to get in there or take the manifold off.
So, if the CSI was dumping gas in then the engine should run after swapping injectors.
So I'm fairly certain I've narrowed it down to injectors but now I'm not getting any fuel, just keep on cranking? I don't see anything in my manual about bleeding the fuel rail after install.
I'll get into it again tonight and see what I find, thanks for the tips.
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“So, if the CSI was dumping gas in then the engine should run after swapping injectors.”
Why do you think that changing the cylinder injectors will fix a leaking CSI injector?
What shape is the AMM on this car? I forget if I read about how it runs unplugged. It will start in limp mode but will not have power above 20 mph.
Just something to think about or I have from my end, like my other posts.
Phil
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I'm saying that after replacing the injectors the car will not start. If the CSI was dumping gas into the intake, the car would run. So, must have been the injectors that were dumping in the fuel? Seems like it, of course I'm not sure of anything at this point.
Unplugging AMM had no effect, swapped it with another AMM and still no change.
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Well throw that theory out the window.
She's running again but just as before.
Plugs are all wet with gas.
I'm going to check the coolant temp sensor at the ECU.
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I put my meter between 2 and ground, got 21,000 ohms and it is definately not that cold in my garage. Looks like I need a temp sensor at a minimum, I guess electrically disconnecting the CSI was insufficient, or maybe the CSI is bad too.
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I take that nack, iy is 13 and ground, not 2! I read the wRong table in yhe manual.
The temp sensor is showing 3300 ojms, seems reasonable.
Maybe the CSI is stuck open?
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Checking the wires at the ECU I found the O2 sensor is not connected. I've never seen a car run this bad over an O2 sensor, maybe this will be a first.
I'm pulling the manifold an extracting the CSI, that thing is nagging at me.
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I pulled the CSI and left the manifold on, man that was a PITA. An allen wrench with rounded edges and a custom cut length make it possible.
Still no changevin how it runs, is this really just an O2 sensor?!?!
It really seems like there's something else amiss.
The engine runs very rough, bucks and kicks like it's timed wrong, exhaust is loud...
#1 cylinder is closest to the front of car and the cam lobes for #1 should both be up denoting the compression/firing stroke, the rotor should point to the #1 wire, that's TDC correct?
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"#1 cylinder is closest to the front of car and the cam lobes for #1 should both be up denoting the compression/firing stroke, the rotor should point to the #1 wire, that's TDC correct"? LoveMy240Wagon
TDC....Top Dead Center...means that the Crankshaft is rotated to a point where #1 piston is at the very top of it's (compression) stroke.
In this position Crankshaft journal #1 is at the... TOP Of It's Arc, and In DEAD CENTER of it's travel between pushing and pulling the connecting rod....the exact spot where it neither pushes nor pulls the piston..
At this point you could draw a perfectly straight line through the center of the piston, along the center of the pushrod, through the center of the crankshaft journal and on to the center of the main (crankshaft) bearing.
In your response, you omitted a important part of TDC, the position of piston #1.
The rest of your statement is true.
Back to your problem.
You say that the exhaust is louder than normal.
Could your exhaust system or catalytic converter be restricted or plugged?
steve
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Thanks for the clarification. It seems like I got it right, am I lining up yhe crank wrong? I'll pull the #1 spark plug and see if I can verify the piston is up. The mark at the crankshaft seems vague at best.
I don't know what's up with the exhaust, I think I'll disconnect it just to be sure.
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Before disconnecting/dismantling the exhaust try shaking the cat very hard and listen for rattling inside. If you hear rattling it could be broken baffles which might cause a clog. Also look for debris in the tailpipe.
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I swapped all injectors with a spare set.
When I pulled the old injectors they were not soaking wet and did not appear to be leaking.
I was not able to pull the CSI, seems like I need to modify an allen wrench to get in there or take the manifold off.
So, if the CSI was dumping gas in then the engine should run after swapping injectors.
So I'm fairly certain I've narrowed it down to injectors but now I'm not getting any fuel, just keep on cranking? I don't see anything in my manual about bleeding the fuel rail after install.
I'll get into it again tonight and see what I find, thanks for the tips.
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Did you observe that the vacuum hose of the FPR is full of fuel?
Goatman
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Nope, dry as a bone.
I got myself a Bentley manual, time to do some diagnostics (ok, that time was awhile ago).
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Phil, thanks for all the help.
I have already swapped the FPR, that is why I hesitate to buy another.
I reset the timing belt just to be sure (did not appear to be off).
I electrically disconnected the CSI.
I disconnected the vac line from the FPR and the return fuel line (rerouted to container).
The car still runs extremely rich, plugs are soaked.
I suppose I'll have to pull the entire CSI to be certain it is not the cause.
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I didn't smell the oil but it seemed to be the correct viscosity and color. I'll check again for smell.
Every plug is fouling.
I only electrically disconnected the cold start injector, I'll pull the whole thing out.
Thanks for the tips!
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My guess is you got a bad FPR. And since you recently replaced the timing belt, it jumped time. The smell, possible burnt clutch.
--
Post Back. That's whats makes this forum work.
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Checked the timing, it's good.
If the fpr is bad then what is blowing it? I just replaced it. Would a blocked return line do that?
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Remove the inspection plug from the header pipe if you have one. I am betting of a collapsed catalytic converter.
In lieu of pulling the plug, you can tap the converter...if it sound solid it probably is, if it sounds hollow...it probably is and the matrix is all caught in the resonator.
Mike
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I don't have an inspection plug but I tapped on the cat and it is definately solid.
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Interesting that you would say that Mike, I had a nagging feeling about the exhaust being plugged. I have no idea why I considered that, it just "feels" like something is stuck somewhere in the system(s) not allowing air/fuel/exhaust to move through.
Any idea how that would cause a rich running condition or are you thinking that's a separate issue?
I'll give the cat a tap or two and see what I get.
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