Well it helped sort of... at least for an hour, New dizzy... same problem but not as bad. Options

[Dr Evil]

I agree that TS1 or 2 could effect. One of them is directly linked to the MPS circuit in the ECU. Not sure which one.

[jim912928]

I had a problem simliar to this with my 1.8. It would run smooth as could be then all of a sudden start bucking and running like it was on fewer cylinders. When it was running rough I went to the engine and started pulling plug wires to see which cylinders were affected. Found the "dead" ones...then I started jiggling the fuel injector connections and bingo...bad connections with the harness at the injector plugs. The wires get real hard down there. Fixed those and the problem never came back. So, good idea to check the harness...and I'd check the injector plugs and the few inches of wire behind those.

[tdgray]

Hi guys...sorry took the night off from car stuff.

Brad - Doc - Geoff. Yes the plugs are "sooty" with "fluffy" build up.

Brad - I never though of this being an oil problem. The plugs do not smell of gas. They are not gas soaked. This is why I was questioning my valve job... like it is not expelling exhaust gas properly and leaving it in the chamber to build up.

Doc - I agree with your statement on the wiring harness.

The injectors are the yellow ones.

Brad - I will post a pic of a plug shortly.

JK - plug wires are about a year old. OEM Bosch wires.

Geoff - no immediately from startup the car smells rich. As my wife says.. that car stinks (IMG:style_emoticons/default/biggrin.gif) I'm going to try a few more things and suggestions from everyone and if they don't work I am going to ship the MPS back to you for testing.

[JohnM]

My experience with Djet runs super rich after it gets to normal operating temp (after 1hr drive) with sputtering, bucking.

CHT faulty or more likely loose/stripped/bunged up threads.

checks:

-sniff exhaust pipe see if you smell fuel indicating super over rich condition.

-Mark (Batlett914) stated a quick on the spot check once symptoms begin occurring would be to disconnect CHT from harness and connect harness lead to ground through a 100 ohm resistor. This will send normal operating temperature CHT signal to ECU and car should let the car run again if problem was bad/loose CHT (it may not idle good at this fixed resistance setting and you may have to keep rpm up above 1000). (DO NOT connect harness lead straight to ground! In my experience you may burn out tired 33-year-old ECU CHT circuit without any resistance.) Note: if super flooded you may have to disconnect fuel pump relay or fuse at engine compartment relay board and burn off flooded condition before trying to restart. If your car runs good after this then you have narrowed it down to either a bad CHT in hot run condition or the CHT is coming loose as the head gets hot and expands. (my CHT was coming loose as PO or PM (mech) looked to have tried jb welding in place which is bad as 1) will not make good ground contact, 2) will eventually start coming loose and giving you this pain in the ass problem.)

-Check CHT tightened snug. If not then tighten it, drive again until symptoms occur and then check tightness again. If it is again loose at all (like mine was) it is jumping threads, rattling around in the head and not making ground contact momentarily making ECU send mega over rich injector-on pulse length giving bucking, sputtering symptom. CHT head threads eventually will become thrashed to the point which when CHT stays off ground connection too long mixture will stay so over-rich as to make engine impossible to run/start. Fix-coil/insert CHT head threads.


So progression of driving symptoms of a loose CHT:

1. Runs fine on start up/cold and first starts getting a little loose at hot engine temp and momentarily looses ground contact giving you only momentarily bucking, sputtering as body of sensor connects/disconnects from threads (ground). You shrug off as a little electrical glitch or air bubble in fuel line and keep driving. EXTREMELY hard to troubleshoot at this point as it is intermittent and may only occur occasionally when at normal engine or hot op temp and when you test CHT you will probably get good reading. If you ever experience this condition when driving a djet I would check CHT is tight/snug in head right away. I would also suggest checking CHT tightness regularly at every other oil change intervals just as a standard maintenance procedure. DO NOT over-torque! It is a relatively shallow, fine thread in soft head alloy.

2. CHT starts getting looser- you drive twenty minutes to store and it works fine, park, shop come out and car will not start, going to flooding condition (you smell exhaust pipe). As car sits after driving for 20 minutes or so and parking, heads initially get hotter because fan air is not blowing over them so CHT is now not making ground contact. As head cools say after another 5-10 minutes (plus the fact that you are spraying super enriched mixture into them and cooling them off even faster!) CHT makes ground contact and starts, drives normally.

When it does this parking lot flooding routine, disconnect the CHT from harness and connect harness lead to ground with your pre-prepared wire and 100 ohm resistor, run the flood out by turning fuel pump off with fuse or relay. Power fuel pump again, start, drive home, curse PO/PM, and fix loose CHT/bad threads.

Picture of my new CHT threads:

[tdgray]

Geeesh... trying to get a picture of these plugs is immpossible.

Here is the best one I've got.

They are sooo black that you can't tell what the pieces parts are.

[Bleyseng]

My best guesses are the CHT is bad or not seating correctly causing rich flooding condition. I don't care if its new. Is it a 012 #? Test it with a ohm meter.

or

the MPS has gone wonky. A blown MPS usually will run and not produce fluffy sooty black plugs so I am going with the CHT first.

[GWN7]

http://www.championsparkplugs.com/sparkplu...ling&mfid=2

"Fouling is when the spark plugs firing tip becomes coated with excessive fuel, oil, or combustion deposits so that it is unable to produce a spark. A plug can become fouled from continues low speed driving, improper spark plug heat range (too cold), improper timing (over-retarded), too rich an air/fuel ratio or an oil leak into combustion chamber. A variety of self-cleaning features are designed into most plugs to reduce fouling."