355 bogging

I am experience a acceleration problem between 1500-3500 rpms. This has degregaded over the years and I lost that snap. Its a 99 355 F1. What I have done to date. Brought it to a Fact Auth Serv Rep and he did notice the lack of acceleration, but after two days he still could not figure out what was going on. What I have done:
Changed out the plug wires and plugs. Went with Kingsborne wires (small improvement)
Changed out the coils - OK
Check fuel pressure - OK
Checked Cats - OK
Checked Clutch - Dealer indicated it was the best F1 he has driven
Air filter - check
Have Tubis and Gruppe M

What next... I step on the gas after the clutch is engaged and it just boggs until I get to a higher RPM. It used to snap my neck back. I even race my buddy with a 355 spider and kicks my A _ S, by a lot.

Carmine

 

Time to get a new one!

Sorry, don't have an idea of what is happening. Mine has a lag in lower RPM's but no real bogg. Hope you find the issue.

 

Check my baby out
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If you could find a chassis dyno with EGA, it may point you in the right direction.

 

Check the MAF (mass airflow sensor, located after the air filters). Had a problem with a dip in power around 4000 rpm on a BMW M5. I actually cleaned the MAFs myself and it pulled very nice through the whole registry.

95 and early 96 had two MAF. later 96 and onwards have one.

 

It could be a lot of things (e.g. timing, bad fuel injector, failing cats, failing fuel filters, MAF problem, failing O2 sensors), but I'd reset the A/F ECUs first to see if that helps. It's free. It's quick. Easy test.

Do you hear a ticking sound from the engine bay at idle or when you rev up?

Notice any unusual heat or smell fuel?

What color is the soot on your exhaust tips: grey or black?

 

Had similar problem, turned ot to be O2 pre cat sensors going bad.

 

As has been mentioned you will want to check your MAFS, and the O2 sensors.

On the MAFS make sure that the wire inside is clean, and the connection contacts are clean. You can use some electrical contact cleaner for the inside of the MAFS.

Since your car is a '99 you have the OBD2 setup. As already stated, I would start by checking the O2 sensors in front of the catalytic converters.

Now if all those check out, then you'll want to check the condition of the crank position sensors, located at the front of the engine, on the bottom and side of the crank pully. Make sure that you don't have any poor connections, and that everything is clean and connected properly. Also check behind the rubber boots, that cover the clips, for any signes of busted wires.

 

Tubi = K&N oiled filters = oil on MAF.

Go down to the local auto parts store and buy this stuff from CRC. It should take you 15 minutes to do the whole thing.

At least this will eliminate that possibility, but I vote for unsynchronised throttles.

Jay
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