Engine Problems it will start but wont run. PLEASE READ HELP!!!

[mexpelon83]

I bought a 92 Q45 back in Sept. When i bought it it was in running condition. When you would come to a stop the car would shake but once you would step on the gas it would drive smooth. The car would turn off while driving and I would put it back on N or Parking and re start it that would solve the problem.

One day it just decided to go to sleep. When I turn the key everything turns on inside the car but then the engine wont start. I just get the regular noise when you are trying to get the engine to start. I have taken it to variours diganose places and each one tells me something different.

First:This person told me that the spark plugs had to be changed just a month after I changed them. And that the Fuel Module had to be replaced. He wanted to do it himself and charge me 400 dollars. I went to a local pick at part and got thoese modules myself and with the help of my brother in law we replaced all of the spark plugs and the modudles. You would think that it would start right? NO nothing it still wouldnt go past the starting phase no engine running.

Second:This person came to my house and checked all of the spark plugs and injectors he told me that the timing belt had skipped and that I had to take it somewhere to get it put back in place and that I also needed to have pressure put into the injectors because they were all low. He had that they had to be at at least 148 PSI and they were currently @ 90 and 100. He told me that most possibly I had to get a new engine and that I had to spend at least 700 bucks. I didnt do this.

I then brought a friend of the family that we have known for plus 20 years and he told me that those to people were not right that everything was ok. He told me that most likely the "computer" had gone bad and thast the reason why the car wont go past the starting phase.

CAN SOMEONE PLEASE HELP ME......

[96Qowner]

Welcome to NICO! You came to the right place - we'll get this solved pronto.

I bought a 92 Q45 back in Sept. When i bought it it was in running condition. When you would come to a stop the car would shake but once you would step on the gas it would drive smooth. The car would turn off while driving and I would put it back on N or Parking and re start it that would solve the problem.

This sounds like one or more injectors going bad ... OR ... your Mass Air Flow sensor (MAF). You can easily test the injectors with a multimeter:

http://www.q45.org/ohminjectors.html

And you can try cleaning your MAF:

http://www.q45.org/maf.html

But neither of those is the likely cause of the car not starting.

One day it just decided to go to sleep. When I turn the key everything turns on inside the car but then the engine wont start. I just get the regular noise when you are trying to get the engine to start.

Ok, so the starter turns the engine - it just won't fire up? Good. If the engine won't even turn, you likely have some serious (fatal) problems.

I have taken it to various diganose places and each one tells me something different.

First:This person told me that the spark plugs had to be changed just a month after I changed them. And that the Fuel Module had to be replaced. He wanted to do it himself and charge me 400 dollars. I went to a local pick at part and got thoese modules myself and with the help of my brother in law we replaced all of the spark plugs and the modudles. You would think that it would start right? NO nothing it still wouldnt go past the starting phase no engine running.

It wasn't the plugs. It could be caused by a Fuel Pump Control Unit (FPCU) - is that what you replaced?

Second:This person came to my house and checked all of the spark plugs and injectors he told me that the timing belt had skipped and that I had to take it somewhere to get it put back in place and that I also needed to have pressure put into the injectors because they were all low. He had that they had to be at at least 148 PSI and they were currently @ 90 and 100. He told me that most possibly I had to get a new engine and that I had to spend at least 700 bucks. I didnt do this.

I then brought a friend of the family that we have known for plus 20 years and he told me that those to people were not right that everything was ok. He told me that most likely the "computer" had gone bad and thast the reason why the car wont go past the starting phase.

CAN SOMEONE PLEASE HELP ME......

It's not AT ALL likely that the "computer" went bad.

When you turn the key, can you hear the fuel pump? Is it buzzing loudly? Have someone listen in the trunk when you turn the key. You should be able to hear the pump for 5 seconds. If you hear nothing, the fuel pump is fried. If you hear a loud buzzing, the fuel pump is bad and fried your FPCU, if that's the module you replaced. You'll need a new pump.

Did someone actually test the fuel pressure? If you have pressure, even if it's low, the fuel pump isn't fried and the car should at least start.

You'll get a bunch more responses. We'll solve this thing, don' worry.

[mexpelon83]

Wow thanks for the quick response. I will comment back:

It wasn't the plugs. It could be caused by a Fuel Pump Control Unit (FPCU) - is that what you replaced?

No. I dont think that was the module that was replaced. I just called my house and they said that those two modules that we replaced are the Fuel injections module. These are to modules that are on the cover sheet where the spark plugs are at. I didnt know at all that there was a FPCU to this car.

It's not AT ALL likely that the "computer" went bad.

When you turn the key, can you hear the fuel pump? Is it buzzing loudly? Have someone listen in the trunk when you turn the key. You should be able to hear the pump for 5 seconds. If you hear nothing, the fuel pump is fried. If you hear a loud buzzing, the fuel pump is bad and fried your FPCU, if that's the module you replaced. You'll need a new pump.

Yes, I hear the fuel pump. it sounds similar to the sound that the antenna does when its going up right? Thast what i thought all this time the noise was.

Did someone actually test the fuel pressure? If you have pressure, even if it's low, the fuel pump isn't fried and the car should at least start.

Yes, the second guy who came to my house and did the diganose got this hoes and put it where the spark plugs go and said that the pressure was low. Yesterday after taking out the spark plug sensors we tried to turn it on and it actually turned all the way on and was running for like 5 seconds then it turned off. We tried turningit back on but this time it wouldnt go all the way.

[96Qowner]

148 psi sounds more like cylinder pressure than fuel pressure. I think the "modules" might have been injectors. If so, good. That was probably what was causing the rough running.

It started and ran for about 5 seconds. Again, good.

Now we have to figure out whether you have fuel pressure problems (from a bad pump or FPCU) or an electrical problem. It does sound like your fuel pump is ok, though - not loud. You can get the fuel pressure tested fairly inexpensively. I recommend you do that. Then we can rule it out.

We'll see what the others say ...

[mexpelon83]

148 psi sounds more like cylinder pressure than fuel pressure. I think the "modules" might have been injectors. If so, good. That was probably what was causing the rough running.

It started and ran for about 5 seconds. Again, good.

Now we have to figure out whether you have fuel pressure problems (from a bad pump or FPCU) or an electrical problem. It does sound like your fuel pump is ok, though - not loud. You can get the fuel pressure tested fairly inexpensively. I recommend you do that. Then we can rule it out.

We'll see what the others say ...

Well there are two of them one on each side of the engine. Like I said on the cover that comes off when you need to get to the spark plugs.

( SORRY IF I AM CALLING PARTS THE WRONG NAME. IM NOT THAT CAR SMART BUT LEARNING LOL)

Yes, I hear the noise for 5 seconds and nowadays it has been more loud than before. I keep on thinking that its an eletrical problem. on my dash board the left screen that is under the temp indicator doesnt light up. I know that its suppose to light up because when I first got it that was on. then all of the sudden it doesnt turn on. Also my AC doesnt light up. It turns on but the lights dont.

I am thinking of just replacing all of the hard drives or computers in the car. The one on on the driver and passanger side, the one located above the glove conpartment and now the Fuel one. What do you think?

[96Qowner]

on my dash board the left screen that is under the temp indicator doesnt light up. I know that its suppose to light up because when I first got it that was on. then all of the sudden it doesnt turn on. Also my AC doesnt light up. It turns on but the lights dont.

That's just bulbs - fairly easily fixed. Ask again after we get it running and I'll point you to the posts that tell you how.

I am thinking of just replacing all of the hard drives or computers in the car. The one on on the driver and passanger side, the one located above the glove compartment and now the Fuel one. What do you think?

Nah, hold your horses. The modules you're referring to are the Engine Control module (ECU) and the Transmission Control module (TCU). Neither are likely to be bad. The FPCU is bolted to the underside of the rear window tray on the trunk side. It could be the trouble. It regulates the fuel pump, providing three speeds. The fuel pump draws its power from the FPCU, and when the fuel pump gets old, it draws too much power and eventually cooks the FPCU, which then loses one or all of its speeds.

Here's a thread about the FPCU and how to test it:

zerothread?id=18148

There are a couple dozen people on NICO that know more than I do - let's wait for their opinions.

[1990QOwner]

Have you had the timing chain guides done?

[mexpelon83]

Have you had the timing chain guides done?

Nope, I havent messed around with the timing belts.

[1990QOwner]

Nope, I havent messed around with the timing belts.

It isn't the timing belts. It is the timing chain guides inside the engine. It is a major defect on the Q's from 1990 to 1996 (someone correct me if I'm wrong). If it is not done than it can cause major damage to your engine and possibly cause you to have to replace it . Search for threads concerning this issue, there is several of them on the main body of Q45 threads.

The trouble you are having doesn't sound like anything to do with the timing chain guides but it is possible.

[mexpelon83]

It isn't the timing belts. It is the timing chain guides inside the engine. It is a major defect on the Q's from 1990 to 1996 (someone correct me if I'm wrong). If it is not done than it can cause major damage to your engine and possibly cause you to have to replace it . Search for threads concerning this issue, there is several of them on the main body of Q45 threads.

The trouble you are having doesn't sound like anything to do with the timing chain guides but it is possible.

If you read the original post you'll see that the second person who ran a diagnose said that the belt had skiped. and that I had to get that replaced. But 96QOwner said that it had to do with the fuel pump and the Fuel Control unit so I am guessing that he is more in the ball park since most of the things he asked me i responded to yes.

I am not saying that you are not wrong, but I really dont want to mess with having the engine pop open and deal with that kind of stuff.. I want to wait until the very last resorce to do that and at that time if I dont get it working I am going to sell it for parting out or to a yunk yard.

[mexpelon83]

Thread was started on IOM:

zerothread/290635

Just looking for a little more attention from the regulars. Thanks.

THANKS IN ADVANCE FOR ALL OF YOUR HELP... I AM GETTING TO KNOW MORE ABOUT MY NEW CAR THROUGH HERE....

CAN YOU SEND ME THE THREAD ON HOW TO GET TO THE Fuel Pump Control Unit (FPCU)?

Im going to try it when i get home today.

[96Qowner]

This one?

Fuel Pump Control Unit FPCU

[mexpelon83]

This one?

Fuel Pump Control Unit FPCU

yes, this is the one.... I sure hope that its the Control unit. If thast the case I can go to the yunk yard and get it for WAY cheaper.

I like this site. I already have in mind on coming back here in a regular basis to learn more about the car and how to change some of the things that need to be changed on the car.

[1990QOwner]

The fuel pump control unit is not the only thing that it could be, it could be numerous other things, before you go and jump on the fuel system I would do a fuel pressure check.

[mexpelon83]

The fuel pump control unit is not the only thing that it could be, it could be numerous other things, before you go and jump on the fuel system I would do a fuel pressure check.

How do I do a Fuel Pressure Check?

I know that fuel does go to to the spark plugs because when we took out the spark plugs yesterday they smelled and had fuel on them. Also when I replaced the fuel filter pump the holes were bursting out fuel like crazy. Thats why i do think that it had to do with the Fuel system control unit.

[1990QOwner]

How do I do a Fuel Pressure Check?

Under the hood on the passenger side there are 2 fuel lines, one of them is that feed line and the other is the return line. You want to unhook the feed line right after the filter and hook a pressure gauge onto it. I would recommend taking it to a shop. Any shop could do it in a few minutes. If you can't take it to a shop than you can get a pressure gauge with the right barbed fitting and hook it up to that line. Once it is hooked up than turn the key on and go read the pressure reading. This reading should be around 60 PSI.

There are numerous other threads on this subject. Try out the SEARCH button for more details. Good luck.

[mexpelon83]

Under the hood on the passenger side there are 2 fuel lines, one of them is that feed line and the other is the return line. You want to unhook the feed line right after the filter and hook a pressure gauge onto it. I would recommend taking it to a shop. Any shop could do it in a few minutes. If you can't take it to a shop than you can get a pressure gauge with the right barbed fitting and hook it up to that line. Once it is hooked up than turn the key on and go read the pressure reading. This reading should be around 60 PSI.

There are numerous other threads on this subject. Try out the SEARCH button for more details. Good luck.

Ok so I got home and i look at the FPCU and YES the #4 plug is toasted on the unit and on the connector cable.

Question: Do I have to and how do I replace the injector? ( is that the white plug) ?

[1990QOwner]

So you are saying that the plug is toasted that goes into the FPCU?

[mexpelon83]

So you are saying that the plug is toasted that goes into the FPCU?

Not the whole plug just the inside part of the plug that connects to number 4.

[maxnix]

Thread was started on IOM:

zerothread/290635

Just looking for a little more attention from the regulars. Thanks.

Rather defeats the purpose of IoM, doesn't it?

If that is the offical stance, time to combine them again.

[maxnix]

Once it is hooked up than turn the key on and go read the pressure reading. This reading should be around 60 PSI.

There are numerous other threads on this subject. Try out the SEARCH button for more details. Good luck.

No, more like 43.5 psi at start up or WOT. It's in the manual.

Research of the FSM, TSB and this board will save a lot of time and effort and your money.

Question for thought: If the FPCU is bad, what would cause that failure?

Secondly, why are you relying on all these people who are ignorant of the the VH45DE to advise you about it?

Timing chain guides?

[goody90q45]

Rather defeats the purpose of IoM, doesn't it?

Are we spinning our wheels here? I've read both threads and I'm confused. Originally I thought that the connector on #4 coil pack was fried. Are we talking about FPCU connections, coil pack connections, #4 injector, igniter packs (mounted on plate?). Are you testing/replacing the same parts that we're talking about? Take a look at the drawings in the electrical section (EL) of the FSM and make sure we're talking about the same thing.

[Q45tech]

the injector that is pluged to the box

The connector that is plugged into FPCU

[mexpelon83]

the injector that is pluged to the box

The connector that is plugged into FPCU

Once Again Sorry for not knowing the correct names of the pieces. I am not that experienced.

Yes. Thats the one that I am asking about. If I have to change that also ?

[mexpelon83]

No, more like 43.5 psi at start up or WOT. It's in the manual.

Research of the FSM, TSB and this board will save a lot of time and effort and your money.

Question for thought: If the FPCU is bad, what would cause that failure?

Secondly, why are you relying on all these people who are ignorant of the the VH45DE to advise you about it?

Timing chain guides?

According to 96QOwner and based on what i have read in various threads FPCU can go bad due to and old pump that uses more power than it needs to and also it is caused by driving the car on EMPTY frequently.

Last night when I took the FPCU apart I notice that the pump is the origninal one and that the FPCU has never been replaced ( Hence all that black stuff that was stuck to the screws that hold the FPCU)

About your questions about relying to people that dont know much about the type of engine I have. I did notice that, I have never heard about Timing Guides???? I have heard Timing Chains and Belts but never Guides.

[mexpelon83]

Are we spinning our wheels here? I've read both threads and I'm confused. Originally I thought that the connector on #4 coil pack was fried. Are we talking about FPCU connections, coil pack connections, #4 injector, igniter packs (mounted on plate?). Are you testing/replacing the same parts that we're talking about? Take a look at the drawings in the electrical section (EL) of the FSM and make sure we're talking about the same thing.

Yes, I am talking about the Harness looking white pack that connects to the FPUC. I want to know if I have to replace that also or if I can just connect it to the new FPCU box that I will get today.

[96Qowner]

The white harness plug is probably ok. Clean it up, though. Plug the replacement FPCU in and you'll be fine, I think.

Then schedule an appointment for a fuel pump replacement (new OEM only) immediately, or get 'er done yourself.

I hope it was this simple. Definitely let us know.

[mexpelon83]

The white harness plug is probably ok. Clean it up, though. Plug the replacement FPCU in and you'll be fine, I think.

Then schedule an appointment for a fuel pump replacement (new OEM only) immediately, or get 'er done yourself.

I hope it was this simple. Definitely let us know.

Alright Ill do that when I get home today. I was thinking already about getting the Fuel Pump already. I might just do it myself if its not that difficult or if I dont need special tools. The new OEM Fuel Pump goes for about 300 bucks. I believe.

I know I hope aswell that it was this simple cause I am tired of asking for a ride and being stuck at home on the weekends and just watching my Q there parked..... lool.....

If it was this simple... Ill be doing this to all of the mechanics that I had working on it.

[96Qowner]

If it was this simple... Ill be doing this to all of the mechanics that I had working on it.

Ya, most of us know that feeling ... uh huh ... Infiniti techs experienced with the G50 are rare as hen's teeth these days.

[mexpelon83]

Ya, most of us know that feeling ... uh huh ... Infiniti techs experienced with the G50 are rare as hen's teeth these days.

Yep yep.... If I get mine fixed. I am thinking of buying another one and try to fix it myself.... I like these cars.