My 94 E320 has been idling rough and misfiring the last few days and I pulled theses codes, 5, 7, 8, 23 and 26. I already know about the coolant sensor being disconnected. Car has 126K miles on her and I replaced the spark plugs and the connectors (under the coils) which fixed these issues 50K miles ago when I had the same problems. Replaced the same this time and have the same roughness and codes. What next, take it to my indy? Thanks, guys.

__________________
85 300CD Signal Red/Tan sold
83 300D Manganese Brown 109K
97 E420 Midnight Blue 197K sold
98 BMW 328i Vert White 100K, sold
95 BMW 525i White 125K, sold
93 BMW 525iT Red 193K, sold
95 E320 Green Wagon 125K, sold
94 E320 White 127K, sold
85 300SD 156K Grey (Annie), sold
84 300D Lapis Blue 170K (Judy), sold
99 ML 320 Black (lease), 1998 C230 White (lease)
00 Honda S2000 Red (lease)
86 Mercedes 300E (sold)
84 Porsche 911 Red (sold), 1965 Porsche 911 White (sold)

What a great assortment. When you say you've pulled the codes can we assume you mean from the built-in button and LED? I would clear them all and see what comes back. You've got so many things going on that I would build Arthur Dalton's code reader and see what else you get from the other sockets.

I read somewhere than the blue engine coils are suspect. Should I replace these?

__________________
85 300CD Signal Red/Tan sold
83 300D Manganese Brown 109K
97 E420 Midnight Blue 197K sold
98 BMW 328i Vert White 100K, sold
95 BMW 525i White 125K, sold
93 BMW 525iT Red 193K, sold
95 E320 Green Wagon 125K, sold
94 E320 White 127K, sold
85 300SD 156K Grey (Annie), sold
84 300D Lapis Blue 170K (Judy), sold
99 ML 320 Black (lease), 1998 C230 White (lease)
00 Honda S2000 Red (lease)
86 Mercedes 300E (sold)
84 Porsche 911 Red (sold), 1965 Porsche 911 White (sold)

Agree... don't waste your time on the CE codes , you need to go to the ignition module for sure [ pin 8]

...hust seeing what you have now , I can tell you you have a large vac leak, probably coupled with the egr vale sticking open..

And how do you use this home made scanner? I search and search and find alot of references to this scanner but can't seem to find intructions to make and use it, thanks.

__________________
85 300CD Signal Red/Tan sold
83 300D Manganese Brown 109K
97 E420 Midnight Blue 197K sold
98 BMW 328i Vert White 100K, sold
95 BMW 525i White 125K, sold
93 BMW 525iT Red 193K, sold
95 E320 Green Wagon 125K, sold
94 E320 White 127K, sold
85 300SD 156K Grey (Annie), sold
84 300D Lapis Blue 170K (Judy), sold
99 ML 320 Black (lease), 1998 C230 White (lease)
00 Honda S2000 Red (lease)
86 Mercedes 300E (sold)
84 Porsche 911 Red (sold), 1965 Porsche 911 White (sold)

Here is a good thread, it contains the codes for pins 8 and 14 and the schematic of the code reader

http://www.peachparts.com/shopforum/showthread.php?t=107630

Its not too difficult to use, simply connect pos to pin 16 and neg to pin 1 (or battery neg) and the third wire to the desired pin. Reading the codes is the same procedure as with the built in LED/Switch.

__________________
Daily Driver: 02 E430 4MATIC
In the family: '03 E500 // '04 ML500 // 64 220SE

I made the Dalton code reader and tested the #8 ignition system pole diagnostic and it flashed back 23, which is,"ignition output2 or ignitional coil for cylinder 3 and 4. So I'll order a new ignition coil.

__________________
85 300CD Signal Red/Tan sold
83 300D Manganese Brown 109K
97 E420 Midnight Blue 197K sold
98 BMW 328i Vert White 100K, sold
95 BMW 525i White 125K, sold
93 BMW 525iT Red 193K, sold
95 E320 Green Wagon 125K, sold
94 E320 White 127K, sold
85 300SD 156K Grey (Annie), sold
84 300D Lapis Blue 170K (Judy), sold
99 ML 320 Black (lease), 1998 C230 White (lease)
00 Honda S2000 Red (lease)
86 Mercedes 300E (sold)
84 Porsche 911 Red (sold), 1965 Porsche 911 White (sold)

< >>

That's one way to an elimination diagnostic approach, but code 23 does not always mean the coil is bad .. it can be one of several other common 104 problems...
Resistor/connector to plug for either of those two cyclinders [ check the connectors on the other plug, not just the one under the coil]
Feed connection to coil [ check wire harness]
ECU coil driver circuit [ scope needed here]

Do as you wish , but an easy check now that you have the code tool is to swap the coils and see if the code follows....

I noticed that I had another coil in stock and I swapped it out already. I did notice that the plug to the coil was loose so that might have been it also. Now that it's running smoothly, it's either the coil or the plug connection, but I'm too tire to ascertain which it is at the moment. So next time, thanks, Arthur. It good to finally fabricated the code reader.

__________________
85 300CD Signal Red/Tan sold
83 300D Manganese Brown 109K
97 E420 Midnight Blue 197K sold
98 BMW 328i Vert White 100K, sold
95 BMW 525i White 125K, sold
93 BMW 525iT Red 193K, sold
95 E320 Green Wagon 125K, sold
94 E320 White 127K, sold
85 300SD 156K Grey (Annie), sold
84 300D Lapis Blue 170K (Judy), sold
99 ML 320 Black (lease), 1998 C230 White (lease)
00 Honda S2000 Red (lease)
86 Mercedes 300E (sold)
84 Porsche 911 Red (sold), 1965 Porsche 911 White (sold)

Cool..
The tool is a good addition for that chassis b/c that is the last of the owner accessable Flash Code retrieve... anything after that and you have to get an OBD2 scanner.[ or go to Autozone, etc]

... so , woth the $5 and a little soldering...

You will notice that these late Flash code ECU have quite a bit of storage/diagnostic capabilities , so may as well go in there and see what they have to tell you...

On the spark plug connectors , the common complaint is usually caused by the failure of the connectors under each coil as they are trapped with the engine heat and they rely on a friction/spring pressure connection [ I don't like the design] , whereas the other plugs have a snap connector [ much better]... anyway , b/c the coil fires 2 plugs in series [ waste spark system] , any poor connector in that 2 plug series circuit will cause a misfire , as the spark has to complete the circuit back to the coil instead of to ground like on a conventional system,
Remenber , those connectors are also the plug RESISTORS, so you can not tell a bad one by looking [ unless your x-ray vision is better than mine .. I never fully recovered from that blast of Kriptonite a while back ...]