Engine swap now car wont start?

[kicknurass4fun]

Ok i just got done doing a motor swap on my buddies 90 tsi. The car had a dead cylinder thats why i replaced the motor. I know the motor isnt gettting fuel. The fuel lines are empty and when i crank it over the fuel pump isnt pumping fuel. The car ran before, and i labeled everything before i pulled out the motor and i know that everything is hooked back up. Is there any specific thing i could have possibly not hooked back up that would cause the fuel pump not to pump? I know the motor runs because if i poor a little fuel into the spark plug holes the engine will fire up and run for a little bit. So either i didnt hook somthing up right or the fuel pump stopped working during the couple weeks the car was parked during the swap. Is there any test i could do to see if there is even voltage going to the pump? What do you guys think I should check. Im all out of ideas thats why im posting this. Any suggestion are helpfull. Thanks for the help.

 

[power=dsm]

i know this sound stupid but is their any gas in the car?

Since you say your not getting fuel, test you fuel pump to see if it's still working

 

[playitlouddsm]

Ok when your sitting in the car turn the key to the "on" position and you should be able to hear the pump make some noise. Usually sounds like a "whine"

 

[kicknurass4fun]

Ok well i just got back from working on the thing some more and it is finally getting gas to the fuel rail but the injectors arent fireing. I noticed a connector plug on the positive battery wire(the wire that connects to the battery and has the three fuses on it). Its not connected to anything and there isnt any connector plugs left that would plug into it. Could this be the problem? What would it go to? I looked on my 92 tsi and it doesnt have this plug so it must be somthing only on the 90 cars have. So any of you out there that have a 1990 tsi or gsx that could tell me if this wire even connects to anything or if it does what it goes to, it would be greatly apreciated. Thanks for the help guys!!!

 

[power=dsm]

that thing with 3 fuses hooks up to positve pole on the battery

 

[eclipsh]

I suspect it is the plug that runs to the throttle box. Should be a plug on the top of it towards the firewall side. See if that is hooked up.

EDIT: Just went out to the garage. Definately the throttle box plug.

RE-EDIT: Better directions: Follow the cable from the throttle body back to the square metal box it goes into. The plug is on the top side of it pointing towards the battery.

 

[PaulN]

The MPI fuse has to be in and connected correctly or the injectors will not fire. It is located on that connector you speak of. I don't have my manuals in front of me or I could help you track down how it's all connected. The first picture in this link might help you locate it:

http://www.dsmgrrrl.com/FAQs/compression.htm

From there you'll have to ensure the fuse is good and connected where it's supposed to be connected.

 

[femmeDSM]

There are two fuses that you'll need to take a look at. The most important one is, like everyone has said, the MPI fusible located on the positive battery terminal. It should be the one farthest to the right, and is a 20A fusible (easy to tell which one this is, as the other two are 30A and should be pink rather than blue).

THere is another fuse in the fusebox at the driver side kick panel that controls the MPI circuit. It is the very last fuse in the box (all the way on the lower right side, Fuse #19). However, you would probably know if this one was bad, as it also controls things like dome light, ignition key light, etc).

If you could, just grab a picture of the 'plug that's not going to anything' and I will match it to my 90 GSX and let you know.

Edit: I should also ask...How are you determining that the injectors aren't firing? Have you checked resistance on the injectors, or checked for voltage at the injector clips while cranking?

Also, just in case you did not know this -- the fuel pump on this car will not turn on with KOEO - the pump only turns on while cranking the car, or via the fuel pump check connector, located behind the battery on the firewall.

 

[kicknurass4fun]

I came to the conclusion that the injectors arent firing because i pulled the fuel line last night and there was fianlly gas in the fuel rail, but no matter how long i crank the motor over it wont start. As soon as i pull the spark plugs and put a little gas in each cylinder and then crank it over the engine starts imediatly then dies after a second or two. So the injectors are obviously not firing. Thanks for all of the help guys. I will go and take a picture of the plug later on and post it. Thanks agian.

 

[femmeDSM]

When the injectors aren't firing, the obvious next step is to figure out what's going on. I would recommend first checking the resistance on the injector pins (should be between 2 & 3 ohms). You can also check for voltage on the injector ECU pins to see if the ECU is trying to fire the injectors. The ECU pins to check should be 51, 52, 60, and 61 (at least those are the ones for a 90). Battery voltage should show up with KOEO, and during cranking, the voltage should drop to nearly 0 each time the ECU tries to fire the injector.

Might sound a little overwhelming, but trust me, the entire fuel system is really quite simple (I learned that the hard way, and with the help of a few of the "Wisemen" here )

Here is an image courtesy of the FSM (again, from a 1990). This might help you understand what's going on. If you need any more info or clarification/explanation of this, just let me know.

 

[kicknurass4fun]

Here is a pic of the plug that i cant find anything to connect to. Thanks for all of the help guys!!!

You must be logged in to view this image or video.

 

[femmeDSM]

Just went down to the garage and took a look for you.....On my car (90 GSX) that plug goes to the cruise control box.

 

[razorawd]

That plug is just for the cruise control box you might want to check the injectors to see if they are stopped up with junk inside and they wont fire like that so check those out and see what happens

 

[Jason84]

looks like a mas plug but normally it would have a longer wire then that.. and that if what it is... would plug into the MAFT (horsepower in a box)


id check to make sure you actually have fuel pressure.. not that there is just a tad bit of fuel in the line.

 

[kicknurass4fun]

Thanks for the help!!! The car has the cruise control removed so that makes sense as to why it wouldnt plug into anything. Other then checking to see if the injectors are clean what other suggestions might you have as now i know everything is hooked up.

 

[femmeDSM]

First of all, I wouldn't be so sure that the injectors aren't firing yet. Check the resistance at the injectors, and test for battery voltage to the injector clips while cranking. You can also check the ECU injector pins and watch the ECU trying to fire the injectors while cranking (battery voltage at idle, then down to near 0v each time the ECU fires the injector).

Things to check from here (not necessarily in order):

#1: How long was the car sitting? Any gas in the tank during that time? If so (even just a little gas), drain the tank, clean it, and add fresh gas. A blockage in the tank near the pump will cause a no-start due to incorrect fuel pressure. Believe me, I went through this one. Haha.

#2: Verify post-filter, pre-rail fuel pressure. Your FPR should be maintaining 36.3 psi, FYI.

#2-and-a-half ( ): Pull the return hose after a round of cranking. Is it dry? Could signify either a bad FPR or extremely low fuel pressure due to one or more of the circumstances listed.

#3: I assume you have installed a new fuel filter? If not, do this. If so, verify that the bolts are torqued correctly. This can cause a significant drop in post-filter fuel pressure, as well.

#4: Verify condition of the fuel pump. Is it new? Check the O-ring where the pump connects to the main fuel line in the bracket. If this is torn, brittle, non-existent, etc, this will make your car extremely hard to start (or in some cases, won't start at all depending on how bad it is).

#5: If you have access to a datalogger, plug her in and see what it reports back from the ECU.

 

[kicknurass4fun]

Thanks for all of the help guys. I finally got the car running.

 

[eclipsh]

So what was wrong?

 

[femmeDSM]

Yeah, inquirind minds want to know. What was it???

 

[kicknurass4fun]

Sorry i forgot to post the answer.

Well it was really wierd. I checked everything and it wasnt starting. As ghetto as this may sound i poured gasoline in the motor. When i cranked it over and it started as usual i just kept giving it throttle and it wanted to die out but it kept it going long enough for it to turn the check engine light on. I checked it with my data logger and it said it was the ignition coil. So i went and unplugged it then plugged it back in. Went in the car cranked it over and it started fine. Kind of wierd because i checked for spark as one of the first things and it had it. So i dont know. But i drove the car around for a little bit and its running good now. I just have a couple other little things to work out but the car is running and thats whats most important to me. Thanks agian for the help!!!

 

[femmeDSM]

Awesome, congratulations
The first time my car started up (after almost a year of sitting) I sprayed some starter fluid into the cyls after cleaning the gas tank, and that's what finally got her resurrected (after replacing virtually every component in the fuel system with no luck). Sometimes they just need a little reassurance, I guess. .

Glad it was something cheap/easy/ghetto,

 

[razorawd]

Good job man it feels good to start the car after you have done a lot of work to it