[Kaneschevelle]

I’ve got a 71 Chevelle with a 572 stroker engine, msd street fire distributor with a Fitech 800 mean street. I have had nothing but problems with this thing. First off I can’t get the fans to come on set at 186 on and 174 off... checked wires and relay. All good. Fan works when jump grounded. I’ve done the whole turn the key off thing to lock it in but nothing.... that was the first thing that went. Shortly there after the car just starts running horrible like it’s starved for fuel. This has happened three times now. Had to totally reset it and it runs fine for like a day then or starts going nuts again. Wires are all shielded. The guy at Fitech told me to take off the ecu and literally cut the nipple off the map seal because he thinks it may or may not be stuck???

any ideas anyone??? I want to throw this thing off a bridge.

 

[Tom Mobley]

Holley makes a nice unit.

what does this mean? "The guy at Chevelle told me...." we don't sell or support those Fitech things.

What exactly is a map shield? MAP sensors have no moving parts.

 

[Kaneschevelle]

Holley makes a nice unit.

what does this mean? "The guy at Chevelle told me...." we don't sell or support those Fitech things.

What exactly is a map shield? MAP sensors have no moving parts.

Holley makes a nice unit.

what does this mean? "The guy at Chevelle told me...." we don't sell or support those Fitech things.

What exactly is a map shield? MAP sensors have no moving parts.

...the person at Fitech not Chevelle. My mistake sorry about that.

The part he is calling a map shield is in the ecu and it’s a little rubber knob looking piece he wants me to cut off the top part of it...

I originally had a ZZ502 with a Holley Carb on it and I love everything Holley. I was talked into putting this throttle body Fitech unit on and Frankly I am very disappointed so far.

 

[Kaneschevelle]

...the person at Fitech not Chevelle. My mistake sorry about that.

The part he is calling a map seal is in the ecu and it’s a little rubber knob looking piece he wants me to cut off the top part of it...

I originally had a ZZ502 with a Holley Carb on it and I love everything Holley. I was talked into putting this throttle body Fitech unit on and Frankly I am very disappointed so far.

 

[smitty454]

Even though you arent running an LS engine, you might have more luck on LS1tech.com. There are a lot more guys on there that know about these types of systems. There are some on the site but a lot of guys here are more familiar with old technology.

Does the FITECH unit come with something like an OBD2 scanner? Will it give you an error code or something of that nature?

Ive heard mixed things about FITECH units. Some guys do have a lot of trouble with them.

 

[1977chevyvan]

Granted my fitech is on my bug and a 2 barrel it is a common problem, the seal for the map sensor is too big and will swell with heat and close off the map senor(ecu won't recognize any load just tps) the map sensor is part of the computer so you must remove it than trim the seal

 

[1977chevyvan]

Also getting a gm or replacement cts from a auto parts store is recommended since the fitech sensors are usually not to accurate, not sure if that will help with your fan issue at all.

 

[-SS454-]

if you are running a new in tank fuel pump, maybe check your fuel filter. My Fitech would go dead lean when i gave it gas, turns out the filter was clogged.

 

[paul bell]

While I have no experience with their throttle body units (I have their LS system adapted to my big block), I would advise you to have a fuel pressure gauge that you can see while driving.

Also, you say all the wireing is shielded. I'm wondering if this is causing some problems. These systems were designed to run with non-sheilded harnesses, they just need some distance from the spark plug wires.

What kind of spark plug wires are you using?

 

[SSJohn]

Have you updated to the latest software?

 

[73Eldo]

Is the FiTech controlling the timing? If yes then I would put it back to stand alone to eliminate that variable for now.

Next thing is do some data logs just after the reset when its sort of running ok then again when its running bad. Should be pretty easy to spot what is changing. Its got to be learning something that is hurting it. Once you know what bad thing its learning you should be able to figure out what the cause is.

 

[Schwany]

The fan wire is a negative trigger wire for your fan relay. If the relay is wired positive trigger, it's not going to work. If you already know all that, I don't know what is going on. FiTech is not the most robust EFI solution by any stretch of the imagination.

That cut the MAP sensor nipple deal wasn't a fix back when I was using the FiTech setup. That might have saved me some money, if it actually helped. I would definitely try that. The system works pretty good when it works. When it doesn't, it's top shelf frustrating to say the least.