The statement was that hot wires are bulletproof, which they are. Which had nothing to do with later 104s - merely a correction of your prior mistatement that later 104s had hot wire. I think you're confusing hot wire with hot film. CIS fuel distributor and EHA problems are very common, and often perplexing. Try a search on a few forums.

And we haven't even talked about the real reason to avoid CIS 104s - the frail EZL that is hard to find used and more costly new than the whole car is worth.

I'm still happy ...
 

I recently saw a new EZL for sale at £700 which is a lot. However, if mine failed I would pay this if I couldn't find a cheaper, used one.

The reason I say this is that the quality of this car is excellent. It is reliable, maintainable and repairable and the value of it to me is equated not to the 300CE's inherent value but to the amount of money I would need to pay to replace it with another car of equal quality, character and reliability.

The CIS 104, in my opinion, is a fine car.

RayH

Where I come from - if you can find one - then they often go for a couple of thousand dollars.
We had a '91 300CE with a missing EZL. Took three months before we sourced a second hand one from Europe - Cost $ 400.00.

So many of those earlier 300CEs are being salvaged for a lack of buyer and dismal market value that the used EZL situation must be loosening up. I'm not saying the CIS 104s are necessarily a bad car - I just don't see the argument that it's better than the HFM 104s. The "bad wiring harness" cars are just so good otherwise.

Well, I haven't posted on here in quite a long time,,,,,
But I have been a Mercedes only tech since 1981.

I have owned more Mercs than I can remember and currently own four of them. (86 190e 2.3-16, 92 RennTech 500e, 91 300e, 88 300e)
......now that you know a little about me here is my opinion.

The 103 wins hands down, to me.

The 103 did have some issues with valve seals-guides, etc,,,,,but they are sooooooo much easier to work on and they can be modified very easily to perform quite well.
The 103 is a very very strong engine. Just look at what "Pumpish" manages to make them do with some boost!

The CIS system to me is the only downside on the 103,,,but only because it is now so old that replacement parts (fuel dist, etc) are high priced.

....but nowadays there are a number of choices out there who make EFI systems that can be added. (Mega squirt-Electromotive,etc)

The 104 is a pain in my ass, and I should know, as I see an average of 10-15 benzes a day at my shop.

I'd like to build a nice 300ce one of these days, for a clean cruiser. When I find the right car-I'll buy it....and if it happens to have a 104 engine in it,,, I will remove the 104 and throw it in the nearest scrap pile so I can put a turbocharge 103 in it!:P

are there any cost effective engine modifications for a 103

We have a 1989 300ce in mint condition.. don't want to mess it up...but wouldn't mind seeing a bit more performance...

the suspension is already modified with springs and bilstein sports... we also have a ronal exhaust on it...

Turbo!


also, the M104 has VVT.. I did not know that

Pretty much the entire performance section of the forum is dedicated to M103 upgrades. The M103 lends itself very well to forced induction, provided a way to add fuel is devised. The M104 is no slouch either, these engines are extremely underrated for power potential (mainly because they're in midsize sedans and don't really get modified like a Supra for example). Many have gone FI on the M103, many of us are still trying to scrounge up the funds for a spare/mockup engine. Off the shelf and/or cheap modifications really aren't available other than making sure everything is clean and working properly--its go big or go home.

I will give my very limited opinion.

I am going to Utah today to buy my very first M103 MB('90 TE). It took me a long time to decide if I wanted an M103 or M104. But at the end of the day, the M103 just simply "looks" sooo much easier to work on. There appears to be room to work under the hood.

The ONLY other gas MB I have ever had was an M119, great engine. Luckily I never had to do any major work under the hood. I am of the opinion that the M103 will be just as smooth and reliable as the OM603.

Most of my previous heavy gasser maintenance as been with Taurus SHO's... MB has been a pure joy in comparison.

The M104 isn't that bad to work on. I've only replaced the radiator, oil changes, and watched my mechanic put a new front main seal on it. Other than that it's not too bad

I'm perplexed by the idea that a 104, especially HFM, would be hard to work on. What specifically? What ever breaks? If it has ASR sure it's a nightmare, but that's ASR not the motor itself. There's a good cure for that too, which is to get rid of the car. The HFM 104s and the LH 119s of the early/mid 90s are the best, longest lasting, most DIY friendly, repairable engines Mercedes ever made.

I like my M104 and this is coming from someone used to the om60x, om61x series engines.

I do need to get new spark plugs and wires and do that job. I'm lucky to not have ASR :D.

...
I've got one for saaale!

2.6L from 90 300E still in the car...

Agreed completely.

Many of these posts are coming from those who have not had at least a couple of examples of each for years of use, I have. The M103 is a fine engine, just that the M104 does everything better and with essentially the same bottom end, it is a very durable engine. The additional changes to the transmission and car body/interior/electricals are IMO the icing on the M104 cake.

On the other hand, if you're going to spend a bunch of money on your engine to equal or exceed the power of the M104, I guess the M103 sounds like it is very modifiable, ... however there are a couple of members here with turbo/blown M104s who have benefitted greatly from the additional valves and breathing available.

I spent a lot of time working on CIS and CIS-E cars starting in the mid-'70s when they came out, L-Jetronic also, and the HFM system of the M104. Personally I prefer the accuracy of a sequential-injection system over the constant injection system, and find it very reliable. I have and will choose the more modern sequential injection HFM system over CIS any time.

To each his own.