86 Nissan d21- fires up then dies

[TommyB50]

Here's where I'm at...
86 Nissan d21 HB vg30
Changed the spark plugs and wires..truck drove great after went to return a wrong part bcz I had an idle issue that was a vacuum problem disconnected..on my way home stopped and put some premium (93 octane) gas in and that's where things went left...after this I noticed intermittent misses, pulled all the spark plugs and checked the gap (.44 right?)..double and tripled checked all my plug wires to make sure they we're all on correct and that none of them we're touching each other, still had the misfire decided to call it last night cause it was late, woke up this morning and now it will start right up, sometimes will idle for less than 1 min then dies, will stay running if I can get my foot on the gas.
Was really frustrated and don't have the resources to pull and swap parts as this is my only vehicle.. Some things to note: ngk copper plugs , 155k miles, and put a bottle of Lucas injector cleaner in.

Seems like a fuel problem, doesn't seem like a fuel pump but possibly fuel filter? Also is it possible the truck can't handle the high octane fuel causing it to miss?

Tried looking for a similiar problem in other threads nothing really quite matched..


Any input is welcome, thanks tom

[TommyB50]

Update: took it to the shop, they just called back and said it ran good for 30 minutes then they started it back up and it ran like s*** again, fuel pump? What's the possibility I got a bad tank of gas? They told me to run out the rest of the tank and then fill it back up... Going to go pick it up tomorrow, things I should try? Or just drop the tank and flush it ?

[TommyB50]

Bump....
Still looking for any input..
Shop called back today said they fooled with it alil bit more and couldn't come to any conclusions..
Fuel pump relay possibly?

Thanks!

[Mphillhouse]

I'm having the same problem. New plugs, wires, rotor and cap. Have plenty of fuel pressure. Now, mine won't start at all. No cracks in vacuum lines.my fuel pump relay was replaced in last year and my truck still did same thing. Some one suggested to me the neutral safety switch (clutch relay?) but I don't think that the starter should still turn over if it was that. I also pulled the fuel filter and blew through it easily. Does anybody have ideas?

[TommyB50]

So I pulled codes and got 12 and 13 which is collant temp sensor and MAF...
Replaced the coolant temp sensor and that seemed to fix it, there are two one of them only controls the temp gauge inside cab and the other interacts with the ecu...it was a pain in the a** to go get to, assuming the one I pulled off was stock it had a yellow plug...I had my truck at a shop they couldn't figure out the problem I pretty much went in there n pulled the codes for them and told them what was wrong with it...and got them the part n they replaced it cause I didn't have the tools to do so...anyways if yur standing in front of the truck looking into the motor it's on the front right of the engine, very hard to get to...have yu tried pulling codes from yur ecu? It's a lot easier than I thought, there is a thread around here or on google that I found that takes yu through the whole process and it tells yu what each number means, there's no check engine light on my truck n they didn't know that, that's why they didn't pull codes, don't know if yurs is the same...currently have a broken ankle haven't got to mess w the truck much...but also dealing w/ a high idle issue...there's so many different things it could be..going to start knocking them out one by one.

[TommyB50]

If it was yur neutral safety switch the starter wouldn't turn as the ecu would think yur truck is in gear and it wouldn't let the starter fire...

[2jzhardbody808]

I have an 87 hardbody/pick-up, it only starts when I floor the gas and my idle control or the little mechanism that controls my idle was frozen, I got it unfrozen but still doesn't work right. I live in hawai'i and can't find a replacement part, also when I'm in gear and rolling down hill, actualy it's when im in gear and not pressing the gas it starts bunny hopping, and clues on how to fix that. Also woundering if it would be better to throw a 2jz in it, or an sr20?