[DMCForum] Re: Poor running

["checksix3" <jetjock11@xxxxxxxx>]

Ok, at the risk of boring some I'll give you a few ideas. I'm not 
there so all I can do is tell you how stuff works, it's up to you to 
develop a way to verify it.

First, put the car back in it's stock configuration. Too many 
variables spoil the mix. Second, I doubt your problem is spark
or ignition unless it's secondary breakdown. Does the car jerk or 
simply have poor acell? Does acell improve after it's hot or does it 
do it all the time?

Third, forget the 7 psi low fuel pressure. It's not an issue. You can 
correct that by adjusting the proimary regulator. (However, that 
shouldn't be done unless you explore the root cause for it). No 
matter, 7 psi low should not be a problem in this case.

If only cold: Acceleration enrichment is done both by the CPR and CI 
system but when cold it's the CPR that counts. Have you checked for a 
dip in control pressure when the TPs are opened quickly? (You do have 
a Bosch gage set right?) If not, bad on you. I'm amazed at how much 
money people will spend on the car for frivolous things and not buy 
the one tool needed for any real FI troubleshooting.

Does the CP start off low during a cold start and rise to max within 
5 or 10 minutes? (The CPR sensing engine heat has *nothing* to do 
with cold start and warm up enrichment, anyone who tells you 
otherwise doesn't understand the system). The CP should reach max 
with 10 minutes (in fact, that's Bosch's spec from the CPR overhaul 
manual). Hook up your gages and check for this.

If hot: CPR warm up is not a factor but acell enrichment may still 
be. After all, the CPR's job is to provide both warm up and acell 
enrichment and it uses different functions to accomplish these tasks.
look for the proper dip in CP during acelleration.

Check for freedom of movement of the A/F metering plate and fuel 
dizzy plunger. It may move when you push on it and the injectors may 
give the same volume but you need to check it under normal operation. 
Normal mass flow through the engine is required for this, I see 
you've already checked for intake and exhaust obstructions. Does the 
metering plate swing when you goose it? Bleed off all fuel pressure 
in the system and see that it is absolutely free from binding. 

How does it run with the Lambda shut down or the O2 sensor 
disconnected? Don't do this for long if you have a cat but try it.
(You can run without the Lambda but you'll need to manually set your 
mixture in the proper range to avoid posioning the cat).

Too bad you don't have a EGR or A/F meter. Checking AFR at idle is 
usless for this kind of problem, you need an A?F meter or better 
still, an EGR. I keep telling you to put one in full time. Also, it's 
too bad you can't scope the ignition system. As combustion pressures 
increase it takes more power to jump the plug gap due to what's 
called the pasion curve. (A little plasma physics at work there, a 
spark is nothing more than ionized gas, ie; plasma).

I would insure the CPR is providing acell enrichment first. Then the 
CI metering system. Next check the timing, is it advancing under part 
load? Your word doc really doesn't give enough details for a good 
diag without some more feedback. The trick is as I told you before: 
instrument each system to where you can observe it while driving.
But first undo everything you've done and put the old stuff back on.
Minimum, put the Bosch kit on there and check pressures from a cold 
start and during part load. Also port into the manifold and see if 
the vacuum spike at the CPR corresponds to CP dipping.

There is way too much nonsense about new coils and such as power 
enhancers, I have to laugh everytime I read that stuff. Put your old 
coil and ballest back on, assuming you have tested them and they 
check out good on the bench. Every one of these systems and 
components can be verified either on the bench or in the car, you 
just have to be creative and know what their correct behavior should 
be. You simply need to verify one fucntion at a time and ove on to 
the next. The best way to treat any system is to break it down as a 
seperate system and avoid looking at it as intergated into the car 
until you've verified it's proper operation. 

Email me off list for more help if you want it...

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