Mr. Magoo

While driving my '86 Vette doing around 30MPH I'll mash the throttle and sometimes the engine will bog down then proceed to accelerate.


What causes this..........too much fuel? I replaced my stock injectors to a set of Ford SVO 24# injectors and set my AFPR to 47lbs. Is this too much? I followed what T.P.I.S suggested.

95AquaC4

Just a quick easy one....fuel filter new??

93TorchRedC4

scorp508

Mark,

(bear with me, I always mess this up.)

GM rates their injectors at 42psi. Ford measures theirs I think at 37.5psi or something like that. (maybe I'm totally backwards and/or wrong)

Putting 24# ford injectors in at 42psi is more like putting GM 26# injectors in. Upping the fuel pressure is even more. I'd suggest dropping that down at least to 42psi for now if you can. I would say definitely some extra fuel could be causing your bog, but with your new intake you might benefit from some more (not at lot) because the added air would make the car a little lean. So for now drop it to 42psi and see if it feels any different.

Mr. Magoo

Brand spanking new. :)

Mr. Magoo

Ok I'll lower it a bit to 42psi and take it for a spin....................is that clockwise lowers pressure or..............???

scorp508

Counter lowers it. :yesnod:

Mr. Magoo

Thanks, I'm off to the store to buy my own gauge...............I used Ken's to set it.

Damn rain....................IT'S Pouring out!!! :mad

JOHN89

Any black smoke? Scorp is correct about the ratings being different. I went thru this for awhile. I got a little flack for it a while ago but lets try it again. For my specific setup, the 24# Ford injectors were too big. GM rates their injectors at 43.5psi which is 3bar (euro) if I remember correctly. Ford rates their injectors at 39.5psi. So like Scorp, said your way rich at 47 psi with the Ford injectors. In fact its like a 26# injector. I lowered my pressure down to 36 psi (as low as it would go) and I was still too fat! The equivalent of 22.91# injectors! You have two options, change the injector constant in the chip or put the stock ones back in. The ecm will compensate some what , this is where I might get some flack, but not enough for a slightly modded or stock L98. If you don't believe me, pull your dipstick and smell the oil! I bet it wreaks of gas and is dark black in less than 1000 miles! Mine was so I put the stock ones back in. Believe me, I hated to do it because the Ford injectors are a damn good product and I paid a great price for them. I will say the car appeared to run fine with them in. No black smoke, no skipping, nothing. The only symptom was black, black oil with a gas smell with less than 1000 miles on it. Diacom did show very low injector pulse width's across the board. When I pulled the cylinder heads, there was alot of carbon build up on the pistons and valve's. This is just my experience and some may have no problems running them at all. When I put the larger motor in I will use them because I do like em!
Boy did I ramble or what!
John

J Z06

Umm, you might want to wait'll the rain stops. It's been continually pouring all day here.

Vettes don't like to be pushed too hard in the rain! It can get a littttttle spooky if you know what I mean. :)

Mr. Magoo

Wow John that is a lot of info. :crazy: :)

As of right now I lowered the Fuel pressure to about 40psi but I have not been able to take it out for a spin, it's raining like crazy here. :rolleyes:
The only time I witnessed any black smoke was during an autocross event a few weeks ago. As I was watching my run on Camera I could see a little black smoke exiting my exhaust while downshifting..........not during acceleration. :confused:

If this does not do it I will lower it even more but unfortunately I do not have my old injectors................so it better work! ;)


Thanks!

scorp508

Pick up a craig moates adapter for your PROM and then we'll (SloRVette ;)) be able to start looking into burning you a chip to take some fuel out.