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  #1  
Old 10-25-2002, 08:23 AM
LarryBible
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Bosch KE problem

This one is puzzling.

'88 300E: I tightened the clamp on the heater hose at the left rear of the cylinder head. I don't think it had anything to do with my problem, but maybe there is cabling or a sensor there that was disturbed, although I have checked everything in that area thoroughly. I think the following problem occurred only coincidental with this action.

When leaving the office yesterday, the car ran fine for about a half mile. I turned a corner and began to accelerate. It would not make power, but when I gave it about 7/8 throttle it came alive like crazy. It kept doing this for a mile or so of stop and go, slow and accelerate driving.

I then stopped for a few minutes, started it up again and it did the same stuff for a little while. It then seemed to level out after driving for awhile and was fine for eighty miles while on the highway.

This morning it was not bad until about 15 miles from home. The cruise control was set and I noticed the power falling off and the cruise control was progressively putting down the throttle.

I began manually managing the throttle and it required me to FLOOR it for it to make power. Once I matted the throttle the power would come on like crazy, no weak cylinders here.

After about six or eight miles at highway speed it would level out and cruise normally. Every time I would come to a light or have to seriously slow down, it would go through this all over again and make no power at cruise. I would have to FLOOR the throttle for it to make power. When it finally makes power it comes on like you flipped an electric switch, all of a sudden.

Once I got to the office the idle was getting a little rough.

So, to summarize, until it has leveled off on a long highway for six or eight miles, it will not make cruise power, it will only make power if you floor it.

Thanks for any help anyone might offer,
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  #2  
Old 10-25-2002, 10:27 AM
LarryBible
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Steve,

Thanks very much for your response and thoughts.

I may have additional reason to suspect secondary ignition. We began with rain and dampness yesterday.

I will begin the pursuit of the culprit in the morning.

Thanks a bunch,
Larry
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  #3  
Old 10-25-2002, 10:32 AM
LarryBible
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Steve,

Thanks very much for your response and thoughts.

I may have additional reason to suspect secondary ignition. We began with rain and dampness yesterday.

I will begin the pursuit of the culprit in the morning.

Thanks a bunch,
Larry
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  #4  
Old 10-25-2002, 10:55 AM
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Big field here. I'm not sure you have a KE problem, but if you did I would expect a big air leak. Its not likely to be fuel pressure as it would have no reason to improve with full throttle.

It could easily be secondary ignition. The problem can occur two ways. One is that at a certain required voltage the spark finds a lower resistant path to ground shunting the needed spark. The rotor is a common cause of this type event. The second way is that available voltage is reduced (by a bad coil) causing a threshold where required voltage exceeds the current capabilities.

The reason either of these events can fit your senario is that idling is a minimum voltage requirement. Low rpm loading is probably the highest voltage requirement, which drops as timing increases and load is reduced with higher rpms.

Plugged cats probably fall under the same concept as fuel pressure: they shouldn't improve with rpm.

KE electronic control could go wild (not likely) and can be eliminated from consideration by just unplugging the EHA connection after warmed up. Car should run just fine with The EHA unplugged when warm.
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  #5  
Old 10-25-2002, 12:24 PM
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Uh OH,

Larry, any error lights in the dash to accompany this?
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  #6  
Old 10-25-2002, 12:54 PM
LarryBible
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No error lights. I am looking to get back my duty cycle meter, so I can check for an error code at the ECM box. There are several errors that are indicated by the duty cycle at pin 3. I don't expect this turn anything up, but I will check.

I think the ignition system is a good possibility. It's about due for some preventive maintenance attention anyway.

Have a great day,
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  #7  
Old 10-25-2002, 10:07 PM
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Larry:

Check the idle control valve hoses. One of mine was loose it was so hard, and if seriously adrift, you will have screwy response to throttle. I once left a hose off on my old Audi Fox, and had exactly the same problem -- would only run if floored.

I don't think you will have the other problem I had with the Fox -- ice accreation in the venturi in cold weather. Fuel control flap would rise until the car would only run at full throttle -- trailed black smoke behind. Cured by disconnecting the blowby hose.

Peter
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  #8  
Old 10-26-2002, 02:58 PM
LarryBible
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Well, this morning I pulled the cap and rotor and they were indeed in pretty sad shape. I ordered these parts then flushed the heater core radiator and as much of the cooling system as I could and put the new heater hose on.

I replaced the plugs and air filter. I think I will at least put an ohmmeter to the coil and pull the air cleaner and check the idle control hoses as suggested.

Thanks for the responses. I will keep everyone informed regarding the outcome.

Have a great day,
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  #9  
Old 10-26-2002, 06:51 PM
LarryBible
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It may have appeared in the post above that I thought that replacing the plugs and air filter would cure my problem. I had bought these parts a few weeks ago and they were due.

I checked the coil with an ohmmeter and it reads as it should. I expect that means the coil is probably okay.

I removed the air filter and checked all vacuum connections and everything looks good.

I will post mid week with the results of the rotor/cap.

Thanks for the help,
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  #10  
Old 10-26-2002, 11:08 PM
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Larry,

I hope you find the problem before Mon. Morning when I take mine in. I am experiencing the same problem and have been for short period of time. I cant take it anymore, I changed my rotor button, cap and plugs. This problem is driving me nuts. I must give in and take her to a tech with proper tools to diagnose her.
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  #11  
Old 10-27-2002, 11:06 AM
LarryBible
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FYI,

God didn't take nails in his hands, his son Jesus Christ did.

Have a great day,
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  #12  
Old 10-27-2002, 12:01 PM
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Larry,

The holy trinity...God in three forms the father son and the holy ghost. But yes it was Jesus that took the nails for us all.


Have you found the problem yet?
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Brandon



2008 S550
1957 Dodge D100
1967 VW Microbus 21 Window
2001 Suburban
2004 Beach cruiser bicycle
-----------------GO DUKE!-----------------

"It cannot be emphasized too strongly or too often that this great nation was founded not by religionists, but by Christians; not on religion, but on the Gospel of Jesus Christ. For that reason alone, people of other faiths have been afforded freedom of worship here." Patrick Henry 1776

Last edited by drbrandini; 10-27-2002 at 12:28 PM.
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  #13  
Old 10-27-2002, 07:19 PM
LarryBible
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No, I've ordered a cap and rotor and checked a few other things. The cap and rotor should be in Tuesday, so I won't know anything before then.

Good luck,
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  #14  
Old 10-30-2002, 08:41 AM
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Larry,

I have found my problem luckily before throwing in the towel and taking her to the shop. My coolant temp. sensor had become unplugged just enough to make contact intermittently. After plugging it back in Sadie is driving great .................

Good luck,
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Brandon



2008 S550
1957 Dodge D100
1967 VW Microbus 21 Window
2001 Suburban
2004 Beach cruiser bicycle
-----------------GO DUKE!-----------------

"It cannot be emphasized too strongly or too often that this great nation was founded not by religionists, but by Christians; not on religion, but on the Gospel of Jesus Christ. For that reason alone, people of other faiths have been afforded freedom of worship here." Patrick Henry 1776
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  #15  
Old 10-31-2002, 07:40 AM
LarryBible
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I put on the cap and rotor last night. If it ever ran any better, I can't remember when that was.

Thanks Steve for the response. I'm quite sure I would've headed the wrong direction without your response.

Have a great day,
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