87 Maxima 3.0 engine problem

Have you checked for vac leaks?

I have gone over every vac line and both intake gaskets and I am unable to locate a vaccuum leak. I have spent so much time on this problem I am going crazy.

It just about has to be either a vac leak affecting those 2 cylinders or something wrong with those 2 injectors. I assume you've ruled out the simple stuff like plug wires and are using the correct NGK plugs?

Thanks for your help I really appreciate it!! Yeah the cap, rotor, wires, and plugs are all new. I still do not understand why when I squeeze the fuel return line almost shut engine smooths out and runs like it is supposed to. I have never seen this happen before on any car I have worked on. The injectors that are on the engine now came off of the running engine in the wrecked car. That motor ran good before the accident. I am about ready to pull this engine out and install engine out of the wrecked car..LOL

Those 2 cyl are lean for some reason. Have you checked the fuel pressure?

Did you replace all the injectors or just those 2? Is the EGR valve stuck open slightly? That is a vac leak and can cause weird problems. Try removing the vac line to it and see what happens.

I'm going to buy a 87 Maxima GXE tomorrow (with only 79k miles... lovely). In doing some online research, I came to find that there is a problem with the 87's fuel injector. There's was even a standing recall order for them from Nissan. I read this off the CarSurvey.org site, from the owner of a

"I initially bought the car through the internet on a yahoo auction, I paid $4200. A bit high. But I am a Nissan believer. I flew down and picked it up in Florida, car was spotless and had been freshly buffed and detailed.

On the ride from the airport it ran on three cylinders instead of six, appeared to be the spark plugs not firing correctly. Seller repaired. This showed up once again in Louisiana, until then the car ran smoothly. From Louisiana the car fired on three then six cylinders, intermittently, I believe this bumping and forceful jerking back and forth took out two of the motor mounts. I took it to my mechanic who diagnosed that the fuel injector harness was not making correct contact consistently which forced it to fire incorrectly. THIS had been a recall item when the 87 Maxima first came out. This work had been done by a Florida dealer, but factory installation specs direction was that it was to be soldered and not clamped. The dealer had used the clamped method. The repair shop did a timing chain and soldered the fuel harness."

Hope that proves helpful to you.

This is incorrect information. The factory recall came with crimp connectors with heat shrink tubing over them pre installed on the ends of the replacement harnesses. Someone may have installed them poorly but this is how they are supposed to be installed. BTW soldering isn't a good idea in high vibration environments like an engine harness. Every factory harness has crimp connections and they don't give any problems, soldered connections will result in the wire breaking next to the solder joint.

Hi Steve!! Again thank you for your help. I believe the injectors are my problem. I did not work on it this weekend but did start it today. This time it did not get all the way warmed up before it started running rough. The injector rail on the car is off of the running engine that came out of the wrecked car. The way it was running today acts just like it is losing those 2 injectors..I wonder if they have gotten some trash on them since they are the first (#1 &#2)injector on each rail. I flushed the fuel lines and installed new fuel filter when I got this replacement car for the wrecked one. Guess I will pull the injector rail off tomorrow and see if there is any trash in the line...Guess I could try the other injector rail too..lol..Heck thats all I can do is laugh I guess...cause I do not have a magic wand..LOL As far as the wiring harness on the injectors...this engine in this car just had the heads and injectors done before I bought it..not sure how many miles ago but heads and injector wirng harness as been changed. All the injectors have plastic connectors with all clips too so I do not think my problem is there...

Hi Steve!! Again thank you for your help. I believe the injectors are my problem. I did not work on it this weekend but did start it today. This time it did not get all the way warmed up before it started running rough. The injector rail on the car is off of the running engine that came out of the wrecked car. The way it was running today acts just like it is losing those 2 injectors..I wonder if they have gotten some trash on them since they are the first (#1 &#2)injector on each rail. I flushed the fuel lines and installed new fuel filter when I got this replacement car for the wrecked one. Guess I will pull the injector rail off tomorrow and see if there is any trash in the line...Guess I could try the other injector rail too..lol..Heck thats all I can do is laugh I guess...cause I do not have a magic wand..LOL As far as the wiring harness on the injectors...this engine in this car just had the heads and injectors done before I bought it..not sure how many miles ago but heads and injector wirng harness as been changed. All the injectors have plastic connectors with all clips too so I do not think my problem is there...

The injectors do have screens in them to protect them as a last line of defense. I've seen fuel hoses deteriate (especially if someone used non FI hose) and the pieces of rubber plug up the screens. On the single line injectors, these screens are in the fittings on the injectors where the hose goes on them.