recently my car started sugering at idle, it does it randomly- it will be idleing fine and than the RPM's start jumping all over the place, from just about to stall to 1000 RPM's, and than start idleing normal again, and you can hear(and see on the digital display)the IAC valve going nuts trying to compansate for it, the display shows the IAC dosent do anything until the flucation starts so that's not the problem, I thought it was a vacume leak so I blocked off both vacume lines (edlebrock only put in a vacume port in front for PCV and a thredded hole in the side for vacume acc. -I just "T'd" everything off off the one on the side) with a plug and it still does it. by the way it is a edelbrock 1000cfm PRO FLO EFI, and it ran fine till about a week ago, I diden't do any changes to the engine. Any ideas?

 

no codes? tps or o2 sensers check ok, clogged air or fuel filters, clogged cat, you running a custom prom? is the tune up good?

 

no error messages on the hand held controler dyspaly tps shows exactly what it's supposted to on the dysplay, edelbrock's manual says 10-15* at idel and 90 at WOT and I have 13 at idel and 90 at WOT and, the O2 sensor isent used at idle only when the vacume is between 6" and 12" and the RPM is between 1500 and 3500 (I think, the manual is in my car). I have a K&N 14x2 1/2 air cleaner with a K&N extream top that I cleaned about a month and a half ago, I have no cats to clog- true duals with 1 5/8" headders(1 3/4" soon), the fuel filter is a year old and my gauge on the fuel rail says 45 to 65 depending on vacume(it jumps all over with the RPM's so that means the regulator is working). the kit has a has you convert the distributar by gutting it and putting a hall effect swich and a 8 bladed wheel mounted under the roter, and it has you lock the timing out using the control pad and set it to 10*@1500 RPM and that checked good last night. the system is a sequental point EFI with a moterolla proesser and a chip custom burned to my engine (so when I put my roller cam in later this year I have to get a new one ) anything elts to check? one thing I noticed was oil on the intake under where the TB mounts to the intake and it's not from the valve covers unless oil lerned to move uphill- it looks like it's coming from the vacume port that the fuel pressuer regulator hooks up to (the instructions verry specifally tell you not to mess with that vacume line and the one that goes to the vacume sensor) it's been there for awhile and I just figured the PCV was sucking oil from the engine being that I had no baffel, but I fixed that about a two months ago with a soda can and some JB weld (it was the only way I could think of, it works though, I'v had no oil residue in the PCV valve vacume line, by the way epoxy dosen't work for hot oil-even the air force stuff- and a soda can banging aganst rockers sounds realy bad ) :hail: :hail: :hail:

 

btt

 

Does you display indicate the injector pulse rates? Are teh injectors spraying a good pattern, or streaming?

 

around 4.8 ms I think, it's nice and stedy though, the O2 sensor light is green(rich) until after it starts surging than it flips from green to red with the IAC valve. by the way the insructions say the injectors are 28lbs in one place and 30 in another, if it matters.

 

btt

 

hey kinda off the subject but i noticed that your in teh air force... i'll be commisioned in 3 years... (hopefully) as soon as im done college and R.O.T.C. How do you like it? what do u do in there?

 

Does it surge when the engine is cold or warm or both?

 

temp dosent seem to matter, I'v noticed it at the stop sign at the entrance to the parking lot and when the engine is nice and hot and everwhear inbetween.

 

Back in 92 I had a pickup with a 88 tpi motor and every once in a while it would almost die. It revved up and down from almost stall to idle speed. I searched everything and the problem was it didn't do it all the time. 1 night it started it again and I saw a spark jumping from the ignition coil for a few seconds and then stopped. When it stopped the motor idled fine. I replaced the coil and never had that problem again. The only reason I saw it was because it was dark. During the day I never saw the spark. Might not be the same that's happening with your car, but that's what happened to me.