I have spent at least 30 hours researching and testing my car but I have had no success. I have about 10 pages of posts copied from this site that I have used in trying to isolate the problem. I am at my wits end. Any suggestions are welcome.
So here's the story. I had a local, highly respect indy shop do some work. The car ran fine before it went in and at this point I can find no fault with what was done that contributes to my problem.
When I picked it up the car ran like crap. The engine idle is down around 600rpm, the idle is much rougher than normal. If you actuated the throttle linkage quickly the motor stumbles and sometimes stalls. If you take the throttle wide open it just chokes out and stalls. You can slowly open the throttle and it will slowly increase rpm.
The exhaust smells very rich. This occurs when engine is either cold or at operating temp.
To drive it I need to coax the rpm to 2K and ease the clutch to get it moving in 1st gear. Above 2K rpm and rolling it runs better but you can feel it miss through out the rmp range to 6.5K.
It runs on the open road but fells like it is seriously lacking power and not breathing well. I drove about 60 miles on the highway with no change. Thought it might be DME learning. I have to keep my foot in the throttle when stopped so it doesn't stall. It stalled once but started right up.
The tech used a scanner and showed no fault codes. o2 sensor was working, water and air temp appeared to be correct, he thought the dwell on the injectors was rich.
What the shop did:
1 Adjusted timing from a head replacement done before I bought the car. The timing marks on both cams looked like this,
**l l** Bearing cap mark
***l l*** cam mark
I confirmed when done TDC on balancer and both cam marks dead solid perfect and #1 piston at true tdc.
2. Correctly gapped and positioned pulse generator for balancer.
3. Set valve clearances, no major problems just tweaked a few.
4. Balanced throttle bodies using 6 gang manometer
5 installed a mechanically adjustable chain tensioner from a V12 at his suggestion vice the one recommended here.
6. crank and rod bearings changed and checked with plastigauge. (precautionary)
7 New Oil Pump
8 New plugs
9 New spark plug wires
10 Exhaust back pressure check ( no restriction)
11. Fuel delivery pressure is in spec
12 Koni adjustables installed and alignment done.
Everything I described fits the bad MAF symptoms so I sent mine to Injection Labs in Colorado to be checked out. Guess what? It tested fine. Had them rebuild it anyway. Got it back and still runs like crap.
So I have
Tested Cylinder ID sensor wire (coil around #6 spark plug wire) to DME plug, no resistance but specifications say it should be 80 ohms, I read .000 on 2K scale. I checked my old wire and it reads tha same as the new one. I read 5vdc at the terminal as it should.
MAF is getting 12 and 5 VDC at appropiate pins, all wires are good to DME plug
Pulse generator is getting 5v, resistance is 960 ohms and in spec, gap is correct and it is clean. No breaks in wires.
Air temp sensor wires are good. I have 2 sensors and they both test 1.96 ohms at 22C spec is 2.2-2.7 @20C
TPS tested at DME plug. Closed throttle- Continuity
Open throttle - open circuit
WOT Continuity
Coolant temp sensor 2.2 ohms @20C in spec and all wires good to DME
IAC wires to DME good, ohms measure in spec, removed it and was clean. Also visually inspected it is half way open. If i remember correctly it went closed to full open to half open when I cranked the engine.
All cylinders had good compression test. Peaked around 170 psi and very close to each other.
Did I mention no codes were stored? No codes show up.
I took a propane bottle and passed it around the intake boots with no change.
I pulled the fuel rail and all the injectors have a good spray pattern, the rail holds pressure after shut down.
I know this is a lot to digest but I really want to get this solved and I need the cumulative knowlege of the board to throw me some ideas on where to go from here.
I am a fairly skilled shade tree mechanic with a decent understanding of electical systems. I have all the manuals for specifications, electrical and mechanical repair.
Thanks in advance, Rob
Linear Mode
