I've seen several pictures of 3.4 swaps where the cold start injector is deleted. What's the purpose for it's removal and can that be done with a stock ECM?
I've seen several pictures of 3.4 swaps where the cold start injector is deleted. What's the purpose for it's removal and can that be done with a stock ECM?
You delete it because its just one less thing to be a PITA....No emc flashing or modding is needed
People usually upgrade to the 7730 ECM along with the 3.4 V6 engine swap. The 7730 ECM does not need a cold-start injector (actually, it needs you to NOT have one). It also does not use a fan switch (the computer controls the radiator fan). So both those things get deleted.
That said, the stock Fiero ECM does not control the cold-start injector. The cold-start injector is completely autonomous. So you can delete it. However, if you do delete it, the engine will take longer to start when it's cold.
Thanks for the replies. Exactly what I needed to know. Sometimes when my engine is hot it's hard to start, I have to floor it to get it to start. Then there is strong smell of gas, as if it were flooding, could that be the cold start injector acting up?
[This message has been edited by raysr11 (edited 05-30-2011).]
Anybody know what to thread into the fuel rail to plug the cold start injector feed? I have a perfect 3.4 lower intake, and no cold start injector hole to plug, or cold start injector switch to plug either.
I plugged the hole with a short bolt and some pipe sealant. I can't remember the thread size, though. But I do remember that I had to cut the bolt very short, lke around 1/2" long.
If all else fails, take the fuel rail to the hardware store and see if anything fits.
If we're deleting the cold start injector will a 2.8 MPFI Firebird lower manifold work? I thought I heard somewhere that the middle manifold had to be a Fiero piece? To answer my own question, the 2.8 MPFI Firebird manifold HAS a cold start injector.
[This message has been edited by raysr11 (edited 05-30-2011).]
I just went to the garage and checked the cold start injector metal with a magnet. Magnet sticks real good. l will use the 3.4 lower intake and weld up the nut to close off the hole remaining on the fuel rail.
The 3.4 fuel rail is identical to the Fiero 2.8's, but without the cold start injector, much easier if you can find one.
I don't think it would work because if I recall correctly the "block" that the fuel lines thread into is completely different and will not work with stock lines.
[This message has been edited by mattwa (edited 05-31-2011).]
The 3.4 fuel rail is identical to the Fiero 2.8's, but without the cold start injector, much easier if you can find one.
Sorry, but NO, the 3.4L fuel rail is NOT identical to the Fiero 2.8 fuel rail.
That said, I have ONE more of THIS STYLE left over from my old 3.4 build:
Note that there is NO CSI PORT on the rail. but it is otherwise IDENTICAL in every other respect to the 2.8 Fiero fuel rail.
I have tried a few times to identify what engine they came from and the best I can tell is that they MIGHT be found on some 3.1s, but it is NOT from a 3.4L
The 3.4L fuel rail will NOT accept the OEM Fiero fuel block, ( the one in the photo above WILL)
Here are photos of the OEM 3.4L fuel rail. Note the difference in the fuel inlet and outlet port arrangement with the photo above.
EDIT: To mention that if there is anyone that wants the rail *without* the CSI port, (as shown in the first photo), PM me with an offer or I'll be posting it in the Mall section soon.
------------------
[This message has been edited by randye (edited 11-03-2012).]
WRONG ! Pipe threads and bolt threads are NOT interchangeable.
You're right. They're not interchangeable. But FYI, that hole has bolt threads. I know, because I actually took my fuel rail to the hardware store and test-fitted pipe fittings and metric bolts. The bolts fit. The pipe fittings did not.
I'd also like to add that I've had the 'short bolt with sealant' in my fuel rail for several years now, with no leaks.
It is true, the fuel rail (CSI hole) can easily be plugged with a metric bolt (M12x1.25). (I have used a oil drain plug from a motorcycle)
Does anybody know if a Fiero with stock ECM can start without cold start injector Because I have the following problem with the lower intake and therefore want to use the Firebird/Camaro intake: https://www.fiero.nl/forum/Forum2/HTML/134490.html
@fieroall: Obviously you have deleted the CSI. What is the lowest ambient temperature your Fiero can still start with deleted CSI?
I've deleted mine and it always starts immediately, just like before. The lowest temp I've seen while starting is 18f. It just doesn't get much colder than that here......ever.... With that being said, my real concern is weather it's running too lean while in open loop. I'm not sure exactly how much fuel is introduced by the csi. The exhaust smells leaner on startup, then gradually gets richer, backwards from what one would think normal. Ron
I'm not sure exactly how much fuel is introduced by the csi.
Not much, since its only engaged for a couple of seconds while the starter is engaged. Then it shuts off.
I hadn't seen this thread before, but yes, the non-CSI fuel rail which swaps directly to the Fiero is from the '90-'92 3.1 Camaro and Firebird. The 3.4 fuel rail has a different system to mount the fuel lines (see the bracket in the above pic), and it would position the Schrader valve down where you'd have no access to it I think. And the 2.8 Camaro and Firebird fuel rail indeed has a CSI, but its further toward the middle of the fuel rail.
I've deleted mine and it always starts immediately, just like before. The lowest temp I've seen while starting is 18f. Ron
Are you using the stock ECM? If so, the CSI is absolutely useless unless you live in Alaska. Therefore I´ll also delete this **** and swap the lower Fiero intake with the Firebird/Camaro intake which I have already port matched today.
BTW, my Fiero here in Austria never cools down under 4°C (39°F), cos she is always in the garage during winter and only comes out in summer!
I live in the moderate weather of California, and I notice that it takes the engine longer to start if I disconnect the CSI. I've never physically removed it, but I disconnected it electrically as an experiment.
It's an odd setup - the CSI is not controlled by the computer, but the computer was tuned at the factory with the expectation that the CSI will be there. I believe the reason the CSI was used was to provide better atomization during cold startup. GM's mid-80s injectors have a bad spray pattern. I'm not sure, but I think that the transition to Multec injectors happened at the same time as GM stopped using cold start injectors. I wonder if there was ever any car that was built with Multecs and still had a CSI - I think there was not.
I have Multecs in my car. There are some tuning options in the Fiero 2.8L ECM which govern how much extra fuel is provided during cold cranking. This affects the 6 ECM controlled port injectors, not the CSI. I tried playing with these settings for a while, trying to get the car to fire up easily without the CSI connected, but I didn't figure it out. Nevertheless, if Multecs are installed, I still think it should be possible to tune out the need for a CSI. The stock programming is calibrated to expect that extra fuel to be in the manifold though.
Are you using the stock ECM? If so, the CSI is absolutely useless unless you live in Alaska. Therefore I´ll also delete this **** and swap the lower Fiero intake with the Firebird/Camaro intake which I have already port matched today.
BTW, my Fiero here in Austria never cools down under 4°C (39°F), cos she is always in the garage during winter and only comes out in summer!
Patrick
Yes, too my knowledge, it is a stock ecm. However, it's always run rich from day one, but it's an 85, so they're different than the others. Either that, or its been molested at some point. Ron
[This message has been edited by f85gtron (edited 01-31-2015).]
