89LX convert acceleration problem

[Anlushac11]

Im having a problem on my DD 89LX convert

When I first start car the car needs to crank a bit then starts, starts with first hit of key with restarts.

When accelerating after initial start or restart car seems to stumble and miss out badly for maybe about 20 seconds or 100 feet. If I let off gas pedal car seems to smooth out but when I press on gas pedal again seems to continue bogging and missing and sputtering.

Suddenly it seems like someone just flips a switch and car smooths right out and runs fine.

This only seems to happen when first started or restart.

Exhaust and Cat not clogged.

New air filter installed and factory air silencer/strangulator in intake tube removed

Im thinking this is a fuel or spark issue. If its a spark issue I would not expect it to go away x number of seconds.

Bought new spark plugs today, will install tomorrow between monsoons.

Never changed EFI fuel filter before. I know pressure has to be relieved before opening line.

Any help appreciated.

 

[Delray Dude]

a few possible things:

clogged fuel filter
fuel pump is dying
bad fuel pressure regulator

could be a bad coil, but doubtful.

My DD is doing something similiar, but i have eliminated a few things. I can hear the pump click on when i turn the key on - and cold sometimes it'll take 15 to 30 secongs to build up pressure. If I try to start it before i hear the pump shut off, no start. After it does start - instant restarts are no problem. I replace the regulator this weekend with a new one (I was hoping this was the problem) while I was changing my stock injectors to 17 lbs ones robbed off a Buick in the junkyard. Didn't solve the problem - but the car runs much better with the new injectors - computer almost has learned the new settings. I suspect my problem lies in the pump and i think yours might be too, but replace the filter first - mine was pretty clogged. It's cheap and easy to do this 1st!

As for a possible coil thing - my 93 has coil packs and at one point i had a bad coil that made it run like crap till it got up to a certain temp and then ran like it should - usually about mile 3 in the trip. But your 89 doesn't have a coilpack, so I vote for it being a fuel (or lack thereof) issue.

 

[Delray Dude]

Never changed EFI fuel filter before. I know pressure has to be relieved before opening line.
.

Well, yes and not really. Replacing it isn't too bad - just crawl under where the back axle area is and it's right there. I removed the lines from the filter - you do get a little bath - have something ready to catch the fuel if you want, but it didn't spray all over the place - but then again - I let it sit overnight so I suspect the pressure was bled down.