engine problem...MAF ?

[ksultz]

Have an 87 Max that's been acting up lately. Around 2000 to 2500 rpm’s the engine will have a loss of power then recover...almost like if you give it gas then let off the gas then give it gas again. It keeps doing this as long as I keep the car in the above rpm range. If I give it gas it accelerates smoothly without problems. If I run the car lower than 2000 rpm’s or above 2500 rpm’s I do not have any problems. Does this sound like a MAF problem or something else? The engine also has one other problem...It runs rich due to a faulty CHTS. I’ve had the CHTS fault for some time but aside from running rich I’ve had no other problems until now. I don’t think the CHTS is part of the new problem but I could be wrong. Any thoughts on the above problem would be helpful.

[ksultz]

Well, the problem got worse...it started to stumble at all speeds. So I did some research and it pointed me in the direction of the EGR valve. I found the vacuum line running to the EGR valve had a crack in it. Replaced vacuum line...NO MORE PROBLEM

[blackmaxima88]

I'm assuming you know about the diagnostics III mode on the ECU? this is a good way to diagnose almost any performance problem with these Maximas.

if you plan on working on your own, it's advisable to get either an aftermarket shop manual (eg, Haynes or Chiltons) or look around for the actual Nissan factory service manual. They will pay for themselves. the Nissan service manual is the best route to go, it covers every little detail, gizmo, and gadget in these cars and it's the size of a phone book.

any shop manual will have the codes for reading the diagnostics mode III, as well as instructions. basically though, what you need to do is get to the ECU, a little brass-colored box underneath the passengers seat. you may have to remove the seat, but you might also be able to reach a small screwdriver in there by hand. there are 2 LEDS, one red, one green, that you can view from the top and side. on the side is a small setscrew that is used to select the diagnosis mode - it ranges from I to V (1 to 5). I'd need to look up the exact procedure, but pretty much, you turn that screw until both LEDs blink 3 times, then turn the screw the whole way back, then count the number of times each LED flashes. that's the trouble code that you look up to see what is wrong. a trouble code of 5 green/5 red indicates no problems.