**Qaking and FestivaBiker** engine stumble!?!?!

[rotinaj13]

I figured I should get the 2 of you together, to try and fix this thing. I appreciate both of your time and patience with this lol I am at the end of my rope with it. I tryed the vaccum guage today held pretty stedy at 17. There was a hiccup the car has here and there where it idles down and acts like it is 2 low then idles back up, the needle sunk to 10 there. When I rev it up (from the butterfly) it went to zero and snapped back to around 20 then leveled off at 17. When I rev it from the butterfly it hesitates then revs. Like a short puase till it revs. When I rev it from the gas pedel it revs right up with no hesitation. I am just about to head out for a test run, with no brakes :evil: , and I will also test it with the test connector grounded. thanks

[darkdan]

17 is kind of on the low side. Mine is 20 and it used to be 22 (i'm thinking weather).

[rotinaj13]

I just got the check engine light installed. The ecu isn't storing any codes. I started it and let it run no light. Then jumped the diag wire, the light came one and went away on the key on test. I did the engine running test and still nothing.... I am figureing the vac. test was on the low side because it is 10 deg out, and I got 1 cyl with a stuck ring. would the cam being a tooth off trip a code?

[qaking]

AJ,
I was re-reading some of your earlier posts:
You said your timing was 15 degrees? It should be 10 degrees BTDC.
Reading your vacuum post above also indicates a possible timing problem.

Remind me what was the problem with your brakes?

Maybe we need to get in the chat room again.

[rotinaj13]

LOL i got break checked after we had talked and I blew out a steel line lol oops. I am in the chat bud lol I am going to recheck the cam crank and dist timming as soon as i get a half way nice day.

[rotinaj13]

ok rechecked cam and disty timming the cam is right on and the disty is timmed at 10 now. It still hesitates though. in my drive I can rev it right up, but driving it messes up. I took it out and when I shifted into 2nd it was at 1 and a half k, but i started to give it a lil gas lightly pushing the gas and it cutout then when i let off it came back. When I get a heavy foot it coughs and goes, but coughs here and there while acceling.... It's wires aren't leaking, new fuel filter, new plugs bosche 4's.... could it be the fuel injectors?

[rotinaj13]

new air filter and added fuel injector cleaner to car.. didn't run it enough for the cleaner to have enough of an effect but it still does it. It seems to b in the low rpm range. when sitting I can floor it and see the tach drop a tick the climb... this thing is getting annoying!!!

[FB71]

did you check the fuel pressure? sounds like its dropping off under load.

[rotinaj13]

does autozone rent out a fuel preasure guage? or how is the best way to check it? cause I think it is comming down to the last details.... :? thanks

[rotinaj13]

just a thought I added gas to it today. first time since the swap and when I took the gas cap off it didn't hiss... it isn't preasureinzing the tank could that be a problem? I am just not familier enough with the complete concept to know or not. does the tank need to b preasureized to some exrant?

[rotinaj13]

is there a way to turn the fuel regulator up?

[FB71]

no, no. tank should not be pressurized. the cap only hisses if there is excessive vapor pressure from sloshing the gas around or the fuel being warm. the vapor forces the vent in the cap closed so it doesn't leak out (called key-off evaporative emissions). When the engine is running, the fuel pump sucks fuel out of the tank, and air pressure can now push the vent open so that the tank doesn't wind up under suction. I had a Crown Vic do that once, the cap didn't vent. The pump generated so much suction it collapsed the tank!

I don't know if AutoZone rents pressure gages, but they're usually less than $30. If I remember correctly, fuel pressure should be 45 psi key on - engine off, and 35 engine running. Under load, when the vacuum drops off, it should come back up to 45 psi.

[rotinaj13]

where is the location of the test port for the festiva? the FI is off of a 93... thanks!

[rotinaj13]

ok I called ford and figured out I have to connect it inline. I connected it after the fuel filter. These are the results I got. key on engine off test terminal jumped: 42 , running at idle: 32 , 2nd gear half open thorotle: 40 (which is the same was the WOT run) , 2nd gear @ 1500 rpm: 36 (which is the same as 1/4 thorotle) , in gear and coasting : 30 , When you start it and shut it down the needle slowly goes to zero. I think that covers every thing I tested with the guage. on one of the 1/4 thorotle runs it stumbled and the guage still held 36.... Thanks for the help guys!

[qaking]

Hey AJ! Read your fuel pressure post, take a look at Haynes, page 4-4 to 4-5, did you do all of the steps under pressure check? From what you posted, it looks like fuel pressure is okay. The gas cap on my '90 hisses every time I remove it to fill up.

Refresh my memory, new spark plugs? plug wires? distributor cap? distributor rotor? are you using the distributor, ignition coil and ignition module from the Fuel Injected donor car?

Did you swap over the Idle Speed Control-Bypass Air (ISC-BPA)? (Haynes page 4-13)

And you still have no trouble codes?