328 still no start

The aux air valve should only be bypassing the throttle plate. It should be connected downsteam of the metering plate (look for a spigot on the side of the aluminum casting before the dryer hose) and after the throttle (usually to the side of the plenum).

 

Could take it to Jim Lindsey.

 

Yes and no.

The fuel pump should operate when the plate is deflected *OR* when the starter is activated -- either one.
(The cold injector gets fuel from the pump, too.)

Plate deflection will regulate fuel feed to the individual fuel injectors. If operating properly, regular CIS injectors cut off below 3-4.1 bar. Main system pressure is 4.7-5.4 bar. Control pressure will vary between 2-3.5 bar when cold and 3.5-5 bar warm. (20 minutes after shutdown, you should still have 2.6 bar on the system.)

So you'd be getting fuel to the system when cranking, but, depending on the fuel distributor adjustment, the individual injectors might not be getting enough pressure to be spraying continuously with the metering plate at the rest position.

But I'd think you'd be getting some fuel out of them.

It doesn't take a lot of airflow to light off a 328. Before I had the wiring fixed, my starter would barely turn over the engine, and it would still fire up, even barely turning at all during "cranking". (I thought it was a battery issue -- it turned out to be the aftermarket alarm (starter kill).)

And if there were no fuel flow at all at the rest position, then why bother having a fuel pump cutoff switch on the plate?

Technically, it bypasses the idle adjust screw (both of which bypass the throttle butterfly). All of the air feeds should come through the metering plate. I was thinking in terms of a pinhole leak in the one of the regular lines, so only the aux air feed would be sucking enough air past the plate to deflect it. (Just trying to explore all the possibilities.)

I'd think checking fuel pump operation would be first. After eliminating electrical possibilities then it'd be time to move on to mechanical issues -- CIS pressures and air past the metering plate.

(I've seriously considered going to an EFI system, just to get that pie pan out of the airflow -- but nobody else would be able to maintain a one-off EFI.)

 

I believe this is wrong, but I will admit to not being 100% sure. I am very familiar with th early systems, but the 328 system is a later version. I do have the Bosch Jetrronic book I will see if I can find it.

It can be done, I've certainly considered it. Adding electronic injectors to the stock manifold has been holding me back, but someone here did make it work.

 

Brian,

Other than the frequency valve and oxygen sensor, there's no appreciable difference between an early CIS system and a later one (excluding CIS-E), which your car doesn't have.

One of the first tests that I would do is to unplug the saftey switch (blue connector) at the FD housing. This will enable the fuel pump to run all the time, as long as the key is in the "on" position. Also, this rule out the various relays from the starting/safety circuit. So...key on, saftey switch un-plugged; you should hear the fuel pump and there should be significant resustance on the sensor plate if your were to try to push it down. If you do, you'll hear the injectors "fire". Even if the pressures are way off, the car should still start, albeit run poorly.

Now, try to start the car...If starts and continues to run, you now know that the problems are with the various relays...If not, fuel pressure gauges are the next step.

Regards,
David

 

It sounds like it could be a leakdown problem or control pressure problem. Also have seen a bad thermo time switch do this by firing the cold start valve when hot. If you call me I can go over tests in detail.

Larry Fletcher
CIS Flow Tech Llc.
251-929-3771

 

Have you tried having someone crank the car over while you put slight finger pressure on the sensor plate? As the car is cranking keep adding silghtly more pressure to the plate by hand and she may fire up and run.

have you pulled the plugs to see if they are flooded? Have you checked to see if your getting power at the ignition ECU?

You probably have..but I thought I would ask anyways.

 

I know from the wiring diagram that the fuel pump is enabled during cranking with the plate in the rest position, and any time that the plate is depressed.

I can't say for certain whether there's fuel from the injectors with the plate at rest, but I've fired up my 328 with the crank barely turning -- far too slowly to expect any plate deflection. Yet it had fuel in the cylinders to fire. (Heck, maybe my old injectors just leak. )

Since the system does hold some fuel pressure after shutdown, I wouldn't expect to see much in the way of fuel out of the injectors with the plate at rest, once the fuel pressure drops from 5 bar operating to 2-3 bar shutdown. But then, the injectors themselves cut off below 3-4 bar.

I've been planning to replace the steel injectors with the brass replacements next winter, so I might find out then .... but that's not much help to the OP now.

The fuel pump should, however, be operating either with the "blue connector" off, the plate deflected, or the key in "start". That's the way the relays work. If that works, then the issue is mechanical, and pressure checks would be the next step.

"Runs briefly then stops" sounds like either fuel starvation or way too much fuel.

 

Sorry about all your travails with your 328. From reading the posts I did not pick up whether you have looked at the spark plugs immediately after it stalls. In your final post you said you changed the plugs because they were fuel fouled. Did that happen while cranking or just after the engine quit running?

At the risk of sounding facetious, your coil wires couldn't be switched, could they? Years ago when I first got brave enough to service my 328 myself, I finished it up including a valve adjustment, belts, all the good stuff. When I started it, the engine missed terribly and would not run, finally stalling, and not wanting to restart. I had that good old sinking feeling, almost total panic. Finally I gathered myself and realized I had some of the plug wires switched around on the front bank.

 

If you have spark, air, and compression, then fuel must be it. Too much or too little can cause this. Check fuel pump volume, pressure, rest pressure, volume to WUR, control pressure, power to cold start valve when warm? Also airflow sensor plate height. Then if you have not found the problem you can start looking at the ECU or lambda control. Is the frequency valve buzzing?

Larry Fletcher
CIS Flow Tech Llc.

 

Dave,
Check this out, it might help. I am not sure why your problem started. Did you have it apart or were you adjusting something?
Was it running great and just started acting up?

http://www.birdmanferrari.com/injectors/injector_clean.htm

Any chance the timing belt could have jumped ?

Dave

 

More specifically, fuel *mixture*. Either not enough fuel *or* too much, for the given airflow.

That's one reason people tell you to check a spark plug nose after it stalls -- not to see if it sparks, but to see if there's a film of fuel coating it (which could indicate too rich a mixture). If it's dry, your mix could be too thin, if it's covered with gas, it might be too rich.

That's really your next step -- a correct CIS system tester.

CIS is a *mechanical* fuel injection system, which uses fuel pressures to regulate mixture the way EFI uses computer signals. You can unplug your Lambda loop and other injection electronics (on a 328) and the CIS will still operate "open loop" at base mixture, like earlier CIS systems. If your fuel pressures (controlled by the WUR, the fuel pump, and the frequency valve) are incorrect, your mixture will be off.


Silly thought: just how often are you pushing down on that plate? After I ran system pressure checks on my 328 with a CIS tester, I put everything back together and found that it would crank but not start. During testing, the system had pooled fuel in the intakes, and it was too rich a mix to start. After the residual fuel from the tests evaporated, it started.

But CIS is an odd system. It's pretty reliable when it works. But when it doesn't, you have to check each and every part, one by one by one.
(Great MTBF, atrocious MTTR.)

(That would be the other motive to convert to EFI: for self diagnostics. But most after-market EFIs are "for racing" and don't have diags, either.)


But given CIS's reliability, that's another reason to have a look at your air intake paths -- to make sure it's pulling air past the metering plate. At one point you mentioned that you had air because "there's vacuum at the plenum". That would happen just from cranking. It doesn't verify your air pathways.

 

You still haven't answered the first basic question that David F. raised (or I missed it) -- when you unplug the safety switch and turn the key "on" does the fuel pump run? If it doesn't run in those conditions, there's no sense in looking at any fuel pressure(s) yet.

If the fuel pump does run, try starting (go to pos III) from that condition (pos II with the safety switch unplugged and the fuel pump running).

If the fuel pump does not run with the safety switch unplugged and the key "on", remove the fuel pump relay and connect a jumper wire from the 30 terminal in the female relay socket to the 87 female terminal in the female relay socket -- the fuel pump should run even with the key "off". If it does run (and I'd be very surprised if it didn't since you report that the system does develop pressure during starter motor cranking), try starting with the jumper in place (and the fuel pump running) and see if it will continue to run.
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Since the situation has occured whilst undergoing work on the belts etc., the first thing is to completely go over all connections. Check the crank sensors, coils and ECu, this could be as much an ignition issue. If you did not touch any settings on the fuel distributor, they will still be the same! Sounds like it is firing on the cold start only if it is fuel issue in which case it is a vacuum problem ie cam timing or such not opening the plate. Unfortunately many people start screwing around with the adjustments and make the situation worse.

This definitely needs to be approached from ground zero, mechanical, valve timing then compression, then ignition and only then fuel. That starts with a fuel pressure check, all lines hooked up, then the basic setting for the plate.

If it is flooding the plugs, I would start at ground zero NOW>

 

Quality of fuel load ie mixture and quality of spark ie enough and timing have not been assessed. I would recheck static timing to be at least on the marks. Then I would disable the fuelpumps and spray starter fluid into the intake and try to run the car on that only. If it runs then your problem is might be in the fuel system. Starter spray is highly flamable more than gas so it can disguise a weak spark. The more info you have the more you can eliminate issues. Lets say the car does not run on starter fluid with pumps cut off. Then you know you have a spark issue eventhough you see spark. It could be weak or mis-timed. People who do not pin/unpin cam cogs when they do timing belts are way more likely to mis-time a motor.

 

OK -- understood. Just wasn't clear to me if you had really verified that the FP electrical operation was OK in the run position (with the safety switch open), or if you had only confirmed that the fuel system was pressurized after some cranking operation. If you are sure that the ignition is working on both banks (during the brief good running period after cold start-up), probably does make sense to go to the next level and confirm if the supply and control pressures are reasonable or not -- good hunting!

 

I got stranded a little while back because of old fuel. Now my fuel was more like 18 months old, but your fuel sounds like it is coming up on its first birthday. I wonder if this is just old gas.

(I wasn't much of a believer in old gas trouble until a few weeks ago. I took my old Vespa out for a ride. I rode about _seven_ miles with no issues. Tried to restart after a cup of coffee and no life at all. Totally dead after kicking it for a few minutes. Replaced the plug, still nothing. It's a two stroke, and there's spark and it smells like fuel. What else could it be? In desperation I finally drained the old fuel and put in new fuel. Started on the second kick and ran fine since. That's the trouble with vehicles that get 75 MPG!)

 

And you start the car, it runs for 3-5 seconds and you can hear the fuel pump running right up until it stalls, right?

 

OK, I was away for the weekend and took the Bosch book and read it. There shouldn't be any fuel spraying when the plate is at rest as I read it. This isn't specifically addressed, but there is a sort of warning about depressing the plate when the fuel pump is running and the engine is not (in the section on troubleshooting) because then it will spray fuel. Remember that no matter how slow the engine is cranking that the cold start injector will spray fuel to make it fire. And yes, by now we can never rule out leaky injectors! New brass injectors are on my "to do" list as well.

Wow, that sounds like it was lifted straight from the book!

 

328 tech specs. (The page after the one I posted in miniature, above.)
(By now, a google search on tech specs, etc., turn up a half dozen ad filled "free book" or "free pdf" sites, all referencing the same online "private ferrari document collection".)

Handy data for doing pressure checks.

 

I don't know anything about 328s but when I first got my 84 QV it had starting issues. Some times would take 15 minutes to get the thing started. Would crank on it and sometimes it would run for about 3 seconds and quit. changed out the oem fuse blocks with birdmans and fixed the problem, wasn't the relays, it was poor conections on the back of the blocks. (but changed out all the relays anyway) rockauto.com for relays, cost about $120.00 for all of them.

 

check o2 sensor relay. malfunctioning relay causes car to go really lean. starts on cold start but dies. common problem. porsche sells relay.