Really frustrated here......
1988 Maxima, 90K miles
Developed hesitation during idle and acceleration about a year ago. So I did the basic stuff like:
Fuel pump replaced last yearFuel filter replaced last yearNew plugs / wires recentlyReplaced majority of vacuum hosesNew throttle position sensor
Problem got worse about a month ago. As I tinkered with it, I noticed (not sure how important this is) that when I removed the top vacuum hose of the Air Injection Valve control solenoid, that it ran extremely well, so I just left it off.
Well, about a week later, the problem returned with a heavy fuel smell and eventually wouldn't start (sounded like it wanted to, but wouldn't).
I replaced the coil and the PCV valve, still no luck.
Towed it to a local auto repair shop. They said it was dumping too much fuel and that they replaced the plugs and the oil (said there was fuel in the oil). Then they said it needed a new coolant temp sensor, so they replaced that. They did find a crack around the end of the air intake hose, I can find one of those at a junkyard (would that cause all of this though?).
Well, after that, they got it started, but it still ran like crap and told me it was the Mass Airflow Sensor. They wanted too much for the part / labor, so I was able to drive it home and replaced the MAF myself. I cranked her up and it ran well for about 5 minutes, but the same old problem has returned. The ECU is showing "normal operating" if you can believe that. What could it be????
88 Maxima Problems - Please Help Me
there are a few things it could be but some real testing needs to be done as it seems they guessed their way through it and you too. It can get real expensive going about it this way as you can see.
Start by checking your head temp sensor and its sub harness with an ohm meter. The harness connector is located at the top of the timing cover on the right hand side of the engine compartment. The sub harness runs down and behind the timing cover. With your ohm meter hooked to the connector at the top, gently pull on the sub harness to see if the circuit goes open. if it does your need a head temp sensor and subharness. Be aware though the head temp sensor MAY have been what they replaced but when you do that it is recommended to do the sub harness to as it builds up corrosion.
Something else you should check is your distributor cap look for the "MADE IN ----" stamp on it, if the ---- matches the word italy, throw it away and get one from the dealer with a rotor. They tend to be garbage and cause the spark to bounce all over in the distributor.
Check those couple things then post back
For the record though the first one is very common on the old u11 maxima.
Start by checking your head temp sensor and its sub harness with an ohm meter. The harness connector is located at the top of the timing cover on the right hand side of the engine compartment. The sub harness runs down and behind the timing cover. With your ohm meter hooked to the connector at the top, gently pull on the sub harness to see if the circuit goes open. if it does your need a head temp sensor and subharness. Be aware though the head temp sensor MAY have been what they replaced but when you do that it is recommended to do the sub harness to as it builds up corrosion.
Something else you should check is your distributor cap look for the "MADE IN ----" stamp on it, if the ---- matches the word italy, throw it away and get one from the dealer with a rotor. They tend to be garbage and cause the spark to bounce all over in the distributor.
Check those couple things then post back
For the record though the first one is very common on the old u11 maxima.
Re: (NISTECH)
Nistech,
I replaced the distributor cap, rotor and got some new plug wires, but still no improvement. (The cap DID say "made in Italy").
I'll try the subharness pull this afternoon. When I started it yesterday (it will run but still spuddering), I ran a self-diagnosis and got a 4-2 (fuel temp sensor). The fuel temp sensor is built into the fuel pressure regulator, could it (or both) be the cause of the problem?? I'll let you know how the subharness goes....thanks a million.
I replaced the distributor cap, rotor and got some new plug wires, but still no improvement. (The cap DID say "made in Italy").
I'll try the subharness pull this afternoon. When I started it yesterday (it will run but still spuddering), I ran a self-diagnosis and got a 4-2 (fuel temp sensor). The fuel temp sensor is built into the fuel pressure regulator, could it (or both) be the cause of the problem?? I'll let you know how the subharness goes....thanks a million.
I think the cap was part of your problem, but I just reread your post. did you ever replace that craked intake tube? if not you definitly should. Did you clean the plugs before you tried to start it? If they are still soaked with fuel they wont fire correctly. If you can just pul the plugs and let them sit out to dry off that will work too, also crank the engine over with out the plugs in and you foot on the floor while cranking. this will help clear any fuel left in the cylinders.
Re: (NISTECH)
I'll have to visit a salvage yard to find a decent intake tube. The Nissan dealer looked up that part and it's well over $100. I will get search for one this weekend and see if that helps.
If I've been driving it around since replacing the MAF, would any gas build-up in the cylinders and on the plugs have burnt off by now? (Because I never did clean up the plugs or crank it over to clean out the cylinders after the MAF replacement) I can clean them up this weekend and see if there's any improvement and keep you posted, thanks!
If I've been driving it around since replacing the MAF, would any gas build-up in the cylinders and on the plugs have burnt off by now? (Because I never did clean up the plugs or crank it over to clean out the cylinders after the MAF replacement) I can clean them up this weekend and see if there's any improvement and keep you posted, thanks!
Re: (NISTECH)
Also did you check the head temp sensor harness?
Re: (NISTECH)
I hope I did this correctly......I unplugged the temp sensor from the harness. I checked voltage in the harness (with the ignition switch on) and saw voltage. I kept the probes from the ohmeter in the harness connector and twisted and tugged for a while and the voltage remained (no cut in power). So I guess the harness is OK. I'm still working on getting a replacement intake hose from a salvage yard. I'll keep you posted, thanks.
no you are not looking at the voltage on the harness coming from the computer. you are looking at ohms on the sensor at the timing cover side of the short harness going to it. What you are really looking for is not so much the value but weather or not it looses contact when you gently pull back on it. no tugging just try to pull it somewhat tight.
Re: (NISTECH)
Update - I did check the subharness (correctly this time) and contact was good as I pulled on the subharness, so it checked out fine. Hitting some junkyards this week for an air intake hose. Once I install it, I'll let you know the results, thanks.