This started right after i put in a full new tank of 93 octane ethanol free fuel-a day or so after, and the car did sit 2 days while we weer moving.
-hwere is why i think it might be the case. - car had run perfect all summer- even after sitting all winter while i did the 5 lug conversion etc etc. - i had put stabil in the tank and it was 1/2 full, and after sitting for months fired up first crank- since then and 2 other full tanks no issues at all- has run perfect, until the other day- on the way home after filling up i had felt a buck or two but those of us with d-jet will kind of ignor such things as they may happen on occasion but the 2 tanks i have run sinice it was ini the shop for valves set and timing its been awesome. and all this was done as a pre- tune before the Dragon run this month(octeenerfest)
its not- plugs, they are fine
not- points, i have Hot spark unit
not - wiring harness - thats all new last year-
- check the groundsand all connections to the distributor and coil. - good
- checked the fuel pressure- perfect(i have an in-line gauge)

so i put some fuel treatment in there and hope it does the job. - btw once the car was started i let it run for abot 20 minutes and it seemed to clear out somewhat. was idling o.k. , rand around the community , not over 35 mph, then parked it. --
---- what is your Favorite treatment for fuel? ive used lucas and Sea foam -

Phil
** update - even worse today really missing bad, now it might be looking like electrical spark, maybe hit spark module or injector triggers, or even coil? Will have to trouble shoot Saturday! Sure hope I can get it figured out before teener time next week!

Perhaps a failing CHTS (TS2)? How's our distributor look? Been cleaned lately? MPS holding a vacuum? How about your Throttle Position Sensor (TPS)?

Those seem like sopme areas to check.

All sensors were replaced last year when i installed the new wiring harnesses too,-
so the chts is new but you never know
x-the distributor is in good shape, and put in a new FI trigger points plate at that time too.
x - i do have a very nice clean second distributor that has new vac canistor, new trigger points and FI tp plate etc. so if it does not clear out i could swap them out- i just didnt want to do that yet since its been less than 500 miles siince the tuneup etc.

x-tps is a replacement board from david sprinkle, put in 2 years ago- i have not pulled it to recheck it but i dont think the car has 1k miles since it was installed.

x- mps holds vac properly- was recallibrated 2 years ago, then re-tuned with A/F meter. - ive been running about 12- 13.5 , a bit more rich at warm up/ idle, and 13.5-14.0 at WOT.

On one of the RRC runs, I filled at a local station. In a few minutes, the car would not run below 3-4K RPM. Nothing had changed except for the gas. I put two bottles of gas treatment in, filled with good quality gas and after about 10 minutes the car started running fine.

I assume that I got a shitload of water in the fuel from the station I originally filled at.

Why 93 octane? Does the compression ratio on your engine support the use of fuel with that octane rating?

The Cap'n

I am not an expert on A/F ratios and I am just passing along the values I was given. But 13.5 to 14 at WOT seems a bit lean based on the values I was given. Of course you know your engine better but the values I was given were:


A:F ratio, you want to see:

13.5-12.9 on the gauge while accelerating or climbing,

12.8-12.5 at WOT,

16-17 while cruising, going downhill or decelerating.

o.k., i'll bite..... because it was there- that is to say that is what was available locally in ethanol free gas and thought i'd give it a try - i had been under the impression that we should be running 91 or so, and the other station that has ethanol free gas is 87 and again had been told inthe past that is lower than what factory recommends for these cars, but please feel free to tell me if this is incorrect.

yes, i was thinking that i would try to tweek this a bit on the WOT,

My car has a sticker on the front passenger fender, by the VIN, which I assume has been there since the car was new. It says 91 ROZ/RON. If you look up the equivalent in the USA, it comes out to 87 octane, or regular gasoline.

http://en.wikipedia.org/wiki/Octane_rating

Click to view attachment

I have run regular no lead (with ethanol) for years in my 1.7 D-jet. Gives me no problems.

Not looking good, much worse tonight and really can't even keep it running, so now I'm thinking f.I. points, , hot spark module, or something of this nature
I might have to source a set of f.I. points plate for a 75 2.0 to test. I hope its not the mps. I'm going to order an extra coil just in case too I guess.
It was running perfect just 2 weeks ago.!!!!