first time user here and don’t really know how to work this so sorry if it’s been posted before! I just bought a 89 sedan with the d15b and the mfpi swap was already done and supposedly has 90k og miles. i drove it 2 hours home and it drove great except for about 1 hour into the drive it died when i was rolling to a stop but started right back up again. the day after i drove to church and it drove fine and then on my home home it died multiple times but restarted everytime. it’s still dying but now it’s taking quite a while to start back up. when i start it after not driving for a long time it’ll start instantly but it seems like when it gets hot it does it more and takes longer to start. any help is appreciated

 

literally could be anything. are there any codes on the ECU? could be Fuel pump, poor spark, vacuum leaks, bad ground, clogged fuel filter, distributor issue, wiring issue, clogged air filter, low fuel pressure. Check the basics, get a good factory service manual, and start to troubleshoot.

 

My 89 DX was having similar problem. I checked the PCV valve and it was stuck open. Cleaned it and that definitely improved things. It still stalls occasionally but I haven't reset the ECU and idle rpm like you're supposed to. My DX doesn't have a tach, still trying to figger out how to measure rpm. Is there a tach pickoff somewhere under the hood?

 

yes.. blue wire. it runs up into the dash and gauge cluster but is also at the distributor. I tossed an old tach into mine and used a couple old hose clamps to hold it on. it blocks the trip meter and the spedometer past 85mph but still works fine. Other than that I use an automotive based Mulitmeter with a tach adapter that reads off one of the spark plug wires.

 

Thanks Pewter. I'll look for the blue wire. Did you use an inductive pickup that clamps on the spark plug wire?

 

yes for the multimeter I use a pickup on one of the plug wires. makes it easier for setting idle and such rather than running back and forth looking at the tach.

 

Makes sense. Which one do you have? I was looking at the Cen-Tech / Harbor Freight one but the reviews on its rpm were not great.
I have a DMM that reads frequency (rpm / 60) but need a pickup for it.

 

I dont know about new ones.. I have 2 super old late 90's early 2000's model OTC meters with 2 sets of all accessories I got from a retired Heavy machinery mechanic that still work flawlessly. I believe these are the ones they used to refer to as MegaMeters because of all the features on them.

 

OK thanks. I'll poke around and see what's available.