WHAT'S LIMITING MY POWER?!?!

Flooring it in 5th, the car will not go over 80, and I cannot get it to rev higher than 5,500 RPM for love or money. Sluggish in every gear, and seems to want 4th just to mosey along side streets.

Yesterday, I posted a thread asking how to properly time the electromotive system, as I was convinced my new ignition was the culprit. I reset everything to the generally-agreed XDi advance settings, and it's NOT the ignition.

Any thoughts? A ground problem? Cam timing off? I know how revs can be limited, but what can also (and fairly precisely) limit speed?

 

You have a carbed car ?

So, my....

first guess would be a fuel delivery / mixture issue

second guess would be a partially plugged up exhaust system

third guess would be a large vacuum leak somewhere in the intake system

 

Well, my two long weekend drives were to both diagnose any problems AND also to run down the tanks for a complete fuel and vapor hose replacement job in the coming days, so maybe I'll just put her up and revisit it after those are in.

 

Another data point: Ran fine most of the weekend, but then it started raining and when I put on my high beams and put the wipers on high, got an alternator warning light. It went right off when I switched back to normal beams. Is that normal or something to look at as a possible cause?

 

Most important question:

Did this problem - lack of power as well as the batt warning light - exist before you installed the ignition? If it did not, then I'd bet the ignition IS the problem. Either the ignition draws too much power for the car's electrical system or there was some error in the installation.

Re the warning light, I'd check batt voltage at various RPM as you turn on accessories and see what it shows. Insufficient power could easily cause an RPM "cut-off" as the load increases on the ignition system. What would really be useful is to do this under actual driving conditions...Connect the multimeter to the cigarette lighter socket and have someone monitor the voltage as you go through the gears/turn on lights/AC/whatever.

 

What's the history on the car? I remember you've been asking lots of questions lately, is it new to you? Do you have service records or might this have been why the car was sold? Was there a test drive/PPI?

If you're starting from scratch, I wouldn't start with cam timing as my theory (not that someone couldn't have screwed it up), please describe the conditions more. You indicate that it won't rev above 5500; is it missing as the revs approach 5500 or just slow to rev? You also mention max speed of 80 mph and describe this as precise; does that mean the engine misses or just doesn't have enough oomph to go any faster?

On my first read, I thought the old ignition system was doing the same, but now that I re-read your post, I don't see that mentioned. So did it just quit working when you installed the new ignition? That would be a real big coincidence.

As for the alternator, with such a high load on it, it might benefit from a new belt and good tension. Or hit it with some belt dressing and try it again! But if your driveability problems are present without the blower/lights/wipers on, that's not likely the source. Do you have good voltage to your XDI/fuel pump? How is the XDI getting voltage? How are the fuses? There's the old 308 fuse box issue...

 

Don -

I purchased the car last March, with the understanding that the Seller's mechanic-on-retainer would fix a bunch of things noted in my PPI. He let it sit in a corner of his shop all winter until I got so mad that the Seller discounted the car and delivered it as-is. I bought it because it's perfectly straight and rust-free, but it's got a slew of mechanical issues to be sorted. I NEVER drove it with the old ignition (snow on the ground here), but my PPI specialist did. He didn't mention the power loss, but noted that the distributors were leaking oil badly and the ignition was "iffy." I replaced with electromotive at a factory-licensed installer prior to bringing it home. It's been sitting waiting for the weather to clear, until now...

 

Also, Don -

As to the revving and speed, it pulls cleanly - if slowly - to 5500 revs in any gear, and tops out at 80 on the expressway, and that's ALL the oomph its got. And I'd guesstimate 0-60 around 13 seconds at the moment.

 

I am guessing here, but I guess there is no law against a rookie chirping in. What do these cars run like when only one bank is up? Being two fours glued together, I thought it was smooth but just lacked power. Have you looked at your spark plugs? Maybe one coil is out.

 

My understanding is, all else being equal, if you drop a coil, you're feeding unburned gas through your cylinders, and will DEFINITELY know it. I'm not backfiring or shooting flames, so I have to imagine everything is working there.

 

I will follow this with interest.




PDG

 

Me too

 

When my car lost a bank, it also did not backfire or shoot flames, it was gutless on accel, would only do 70mph with the accelerator to the floor, but in my case, the engine would stall at idle. I imagine you would have mentioned that.

Your problem could be fuel related. How old is the fuel in the system? Possibly it is past its prime and not delivering enough bang when fired.

 

One point is that the +12V power to run the ignition system is marginal at best on a stock carbed 308 -- so changing to a (higher power) Electromotive system won't be helping things (and the alternator warning light wiring is in the same top of fuse 1-2-3 interconnected rivet-plate kerfluffle). What is your fuseblock status? Stock, Stock with soldering added, other?

Also, what is triggering the Electromotive system? The 60-2 crank wheel as described on Nick's site? Is all OK there (spacing, alignment)?

 

It sounds like there is a restriction somewhere. Fuel or clogged catalytic converter.

My first guess would be fuel. Trace the fuel path: pump, fuel filter, rubber hoses to each carb copper screen in the carb. The fuel pump for a carb car should have high flow but, low pressure, fuel filter-new or original?, fuel lines can look OK outside but have increased inner diameter or be damaged from ethanol fuel. In your other thread, you stated that it had old gas and the carbs were rebuilt. Did someone replace the fine, copper screen hear the fuel bowl? This keeps dirt from entering the bowl, but if it is clogged with the "varnish" from old gas, it could restrict the fuel flow. I assume they also put in a new float valve.

A clogged or damaged catalytic converter can limit RPM. However, with these older cats and the slow down lights, I would imagine that you would get a light.

If one bank is out, the engine will still seem somewhat smooth, but with less power. However, if unburned fuel is going into the catalytic converter, the cat will overheat and will probably catch on fire and shoot flames out the exhaust.

What is the condition of the fuel filter? Your airbox does have extra insulation behind the screen by the throat end, so its already restrictive. Try it without the air filter, but put the cover back on and go for a short ride.

I would first verify that you have a spark at each plug. Use a spark plug tester or just pull a wire and ground to engine.

I would also check the integrity of the ground straps: battery to frame and frame to engine block. If the XDI unit is now working, I suspect things are OK, however, your car will run so much better if you pull both ground straps, clean them and the ground points and use new hardware when reattaching. Then cover each connection with dielectric grease to minimize rust. I also added an extra ground strap from the engine to the frame on the driver's side. This can then be used a a pick-up point for the XDI coils, (as opposed to running a wire directly to the battery terminal which can be done).

Once these systems are sorted out and new parts replaced, especially hoses, they are usually stable. I also bought a rust free car that had been sitting many years. It takes a lot of time to go through each system, but it is worth it. And the XDI is a very good system for carb cars. Good luck.

 

My engine DOES stall on idle, but only on startup. I have to give it gas for a minute or two, even with the electromotive, before it settles into a proper idle.

Ignition/timing was one area I didn't want to try and mess with myself, so I had the Chicago electromotive authorized shop do the install. I'm assuming it's correct; they seemed pretty competent. There's a trigger reader mounted to the rear belt cover, and the cog wheel looks to be properly seated.

 

It is NOT a clogged cat. I swapped them with Hyperflow test pipes SPECIFICALLY to prevent this fire hazard situation.

 

Do you have access to a shop that has a gas analyzer? It might be helpful to see what the emissions look like bank to bank and at various RPMs. At least it would tell you if you are rich or lean... Sometimes it is helpful to work from the back to end to the beginning (tail pipe).

Franny

 

True...

It would match these symptoms, but usually the unburned fuel will cause BIG problems on the exhaust side.

People dive for cover, when it flashes off.

It can split your muffler and shatter headers too.

 

This whole electrical / ignition / spark / etc. set of possible scenarios can be ruled out in 10 minutes with an inductive-pickup timing light ---- if you don't have one, pick one up at Walmart for 40 bucks.

Check that you have spark on all 8 plug leads, then shoot it at the flywheel and confirm that you have some realistic amount ignition advance with increasing RPM.

Old-school distributor / points systems can deliver "weak spark" voltage to plugs ---- so, with those systems, you can have a spark, but not high enough voltage / duration for good combustion.

But, now that you have an electronic ignition system installed, that should not be able to happen. I don't know for sure about your specific Electromotive system, but nearly all electronic systems employ transistor circuits for generating primary (to the coils) ignition voltage signals ---- which means they have threshold voltages that need to be reached before they will fire. So, you either have a "good spark" or you have "no spark". You cannot have a "weak spark". And, if there are any power supply deficiencies from elsewhere on the car that result in the ignition module not getting the minimum voltage it needs...... it won't fire at all.

Check that out easily with the timing light ---- if you have spark on all 8 and advance, you have just ruled out any electrical supply and gross ignition faults.

Then start looking at fuel / air / vacuum etc. causes.

Also, the later injected cars with stock ignition operate as 2 banks of 4 cylinders because they have 2 discrete ignition systems, so you can lose one bank. But, does not your Electromotive system have only one crank / cam sensor (trigger wheel) ? If so, it does not operate as 2 separate ignition systems ---- so, it should not be possible to lose only one bank.

Again, I am not terribly familiar with all the different Electromotive systems out there........ so, please verify some of my assumptions as to how yours operates by reading over the literature describing it. If my assumptions are correct, so will be the reasoning that followed.



.

 

You mentioned that the distributors are leaking... How does it look inside the caps? Surely they cleaned all that and replaced anything that was not up to spec?

 

Also, FYI, it's not bad gas. I refilled a fresh tank of premium before taking it out. And the electromotive installer upjetted the carbs to be slightly richer than stock spec, then properly synch'ed them. It was snowing when he finished the work, so he didn't take it out for a test drive, BUT he said it was running properly and showed me in his shop. It turned out to have been dialed in with a bit too much advance, but that's fixed.

 

The electromotive was supposed to be a more-efficient bypass to doing a cam reseal and screwing with the distributors. They're still attached for the moment, though, until I get a decent deal on delete plates.

 

Unfortunately, I can't devote as much time as I'd like to working on this in my evenings, because I have a wedding coming up in a month and lots left to do, BUT I'm gonna go buy a timing light today and see if I can nail anything down.

Otherwise, it's supposed to rain here all week, so this could be a good opportunity to stay indoors, go through and replace all the fuel/vapor hoses, and make sure everything is properly plumbed.

Kinda my thinking at the moment.

 

Keep in mind that when you are troubleshooting ignition systems - the whole system from one end to the other - what works fine in the garage under NO load, may not work at all under load. There is no load with the tranny in neutral, regardless of the RPM. It takes a lot more power to spark at 7500 RPM in 5th gear on a dynO or running down the road than it does in the garage in neutral.

However, with your further info, I'm wondering about the clogged exhaust possibility. I know you removed the cat but an internally rotted/plugged muffler could cause the symptoms.

Firing on only one bank could, as mentioned, also do it but I assumed you had checked for that. If not, I agree it's a strong possibility. I don't know anything about aftermarket ignition systems for Ferraris re whether the system you installed eliminates the "separate engines" of the stock design or not.

FWIW, I had to troubleshoot a car once that cut out only when turning left at a pretty good G-force. It was a faulty coil. Ignition systems can be...interesting.