First off I bought my 94 EJ1 with a LS swap about 5 months ago, just a week or two ago my cars idle sometimes would get low but would jump back up again. It usually idles around 900rpms but it jumps higher and drops lower by a few hundreds. Just today when I went to work my car idled like normal with it jumping around but it sounds and feels like its missing. I was driving home and 2 times coming to a stop the car almost stalled when I pressed in the clutch. Could it be a throtle position sensor or is my timing off, or possably something else? I dont know if it makes any difference the check engine light comes on withen 10 minutes after the car starts. Any suggestions?

 

Have you checked the Check Engine light yet?

may be your TPS

 

Thanks. I havent checked the CEL, im not sure how but ill look it up. I just started my car and when I rev it the RPMs drop to low and it gets so close to stalling. It doesnt matter what rpm im at it stutters. I held it at 1000, 1200, and 1500 and all the same, just stutters?

 

Ok I found the CEL code its 43-Fuel Supply System. My fuel pump went bad 2 months ago and I replaced it. would it still be reading the fuel pump problem, if so how can I reset it. I guess ill take the car into the shop tomorrow and check the timing? but im still stumped on what the problem could be.

 

is it an oem replacement fuel pump, in my experience oem replacement fuel pumps are hit or miss, could be your problem

 

It was a auto parts store brand, I did have a problem with it. I replaced it and it was fine for 3 days then i started having problems again so, I checked everything main relay, fuel pump, and lines, and wire connections to the pump. couldnt find the problem, After spending a few hours scratching my head i decided to pull out the pump. Turns out the power wire had a bad connection and broke off on the new pump. So I got another, and it works. Good thing for the year warranty. Very strange but I see why yoy say hit or miss.

 

Very strange, went to work today and did a little running around town after, I didnt have the stuttering problem. Im just a little confused. Hope all is ok now. after reading the CEL last night it must just reset itself because the light doesnt come on anymore. The car seems fine but please post any suggestions on the problems. It would help incase the problems start again. I thought maybe it was the heat and humidity but today was the same high 80's and high humidity.

 

even though your CEL isnt on, the code is still stored in the ecu, reset your ecu by disconnecting your negative battery terminal

 

my 92 ls did that.

it would idle super low, and at stop lights, the tach would jump hella crazy all over the place, studder, and stall sometimes.

eventually my ingitor in my distributor took a crap n the car wouldnt start.

replaced that and everything was up n running 100% again.

 

Can try cleaning you IACV