No fuel pressure on 91 talon

[skapegoat]

I put a top end on a 91 talon that has been setting for a while. It turns over and gets spark. I unhooked the fuel rail supply and turned on ignition to see if fuel pumps and it doesn't. I put in 5 gallons of gas with stabill on top of what was already in there so there should be enough gas. I can't hear the fuel pump turn on so I went and tried the eclipse I got the head off of and it also does not pump any gas with the ignition on. It was a running engine before I pulled the head off. My question is, is there something that locks out the fuel pump? Also there is some sort of sensor threaded into the water jacket that has 2 vacuum lines going to it that are broken off. One seems to go to what I think is fuel control solenoid on firewall and charcoal canister. What is this sensor called and does it cause the fuel pump not to turn on?

 

[whe3ls]

thats a thermovalve. its not important, get a 3/8 bspt or even a ntp plug will work. just run a vacuum line form a nipple on the intake manifold to the fuel pressure regulator. check the mpi fuse its one of the 3 or 4 fuses on the positive battery cable.

 

[skapegoat]

Is that causing the fuel pump to not work? Visually checked all fuses and they looked good.

 

[pauleyman]

I unhooked the fuel rail supply and turned on ignition to see if fuel pumps and it doesn't

Fuel pump doesn't turn on just with ignition on. ECU has to see a signal from the CAS to trigger fuel pump. That's doing it the hard way. You can jumper it with the factory provided fuel pump check connector under the hood. Just need a piece of wire. This will at least tell you if the fuel pump is functional. It will not tell you if the motor is getting fuel. Injectors need to fire for that to happen. Cars sitting for awhile typically destroy the fuel pump with varnish. I've changed many.

 

[WeaselHack]

Like whe3ls said....that thermo valve isn't important if you've deleted emissions. Do you have access to a data logger? If so, you can toggle the fuel pump and listen for activity. Check the MPI fuse as stated. Worst case carefully redirect the return fuel line into a canister and verify pressure while cranking...

 

[whe3ls]

idk its worth ckecking as the mpi gives signal to the fuel pump. also there is plug you can jump that turns on the fuel pump. ill find out which plug it is

also a bad ecu temp sensor, the two wire temp sensor, can cut power to the fuel pump

there is a fuel pump jumper its a small black connector by the battery, should be taped to the harness, just apply power and if everything is good the fuel pump should come on.

 

[skapegoat]

I don't have access to any computer stuff. I usually work on classic cars and muscle cars this is all new to me other then the 87 crx si I had 10 years ago. So tomorrow I will change out my fuel tank with the good one in the parts car. I'm assuming the pump is in the tank so that should solve the bad gas and bad pump problem. If it still doesn't get pressure where do I jump out what to test the pump for pressure?

 

[pauleyman]

Why wo9uld you go to all that trouble when you can test it first/ THEN if it's bad change it. Jumper is taped to the harness next to the battery. It looks like an unused plus that would accept a single male spade

 

[skapegoat]

My concern is that if gas is bad enough to eat the pump I probably don't want to pump it through the fuel filter.

 

[whe3ls]

it probably should be replaced anyway, a new one is like 20 bucks.

 

[pauleyman]

IF the pump is working I'd let it go. get new gas later than change the filter.

 

[skapegoat]

I found a black and white wire by the - battery terminal and when power is put to it there is just a spark and no gas being pumped. Looks like I have a gas tank swap to do this morning. Can't wait to smell like bad gas all day.

So I got the tanks switched out and everything hooked up. Try to start the motor a few times and finally it fired and ran but real rough. Ran it some more and it starter to run smooth but now after I run it for 5 seconds or so the check engine light comes on and it dies right after. Any ideas? I'm out of them.

 

[ScuzziOne]

Good news is that you ARE getting a Check Engine Light, so there should be an error code stored for whatever is going on. Next step would be to retrieve the error code and see where it points.

I'm assuming you put in a new pump when you swapped tanks? As pauleyman noted, it's not uncommon to have to replace the pump after these cars sit for a while (even a short while for an older pump). Not particulary necessary to change out the tanks though... I've always just gone in through the rear hatch floor and changed out the pump & filter without dropping the tank. Anyway, assuming you've got a good new pump, other fuel related things to check would be the inline fuel filter on the passenger side firewall, fuel pressure regulator on end of the fuel rail, and fuel return line from fuel pressure regulator. An actual fuel pressure reading would be good to verify the fuel system is indeed operating correctly. I believe someone makes a fuel pressure gauge adapter fitting that goes between the fuel line and the fuel rail to allow you to do this easily. If pressure too low, then check voltage on pump, fuel filter, pump itself, and, potentially, the fuel pressure regulator. If fuel pressure too high, I'd go straight to the fuel pressure regulator and associated fuel return line.

Otherwise, just go straight to getting the code to help narrow down what's going on. It's not uncommon for the motor to run roughly immediately after fuel pump replacement and the car sitting for a while.

 

[skapegoat]

Something is telling the fuel pump to shut off. When I jump out the pump to force it on the car runs at higher idle and when driving only revs to 4500 or so. What would make computer kill pump?

 

[ScuzziOne]

Looking at the Service manual table for 2.0L Fuel System Control Functions, there is a Function column labeled "Fuel Pump Drive Control." Scanning down this column, the only associated input functional elements are listed as "Power Supply (ignition Switch Coupled)," "Power Supply (Battery Backup)," and "Crank Angle Sensor." This fact and the fact that you just installed the head, I would guess that there is most likely an issue regarding your Crank Angle Sensor as pauleyman noted earlier. That said, here's the questions that come to mind:

Did you make sure the motor was at TDC and the mating marks on the CAS were aligned prior to installing the CAS? If not, you could be 180 degrees out of phase on the CAS...

If your CAS is not installed out-of-phase, then did you perform a proper timing adjustment/verification after CAS installation? By this, I mean, did you attach the proper timing adjustment mode jumper(s) as per the manual to force the engine to run at base timing, adjust for proper idle RPM, and use a timing light to verify/adjust the CAS to make sure base timing was set correctly? If not, you need to follow the service manual idle and timing adjustment procedures to make sure idle and timing are set correctly. On the 1G, this involves using jumper(s) to over-ride control loops in the ECU such as the auto advance control loop which uses the knock sensor to advance timing. If this system was not proper over-ridden when you adjusted timing, then your timing adjustment likely resulted in a severely retarded base timing. If this is the problem, then you'll need to look up the proper method for a 2G, as I imagine it differs from the 1G method I'm familiar with...

Is your CAS wiring harness properly connected and in good condition? Wiring problems would definitely wreak havoc...

OK, if none of the above, then it's probably time to suspect a possibly bad CAS unit; however, if it was working before the head swap, then it seems awfully coincidental that it would fail during the swap... not to say that it's not possible though...

Best of Luck!

 

[skapegoat]

I'm assuming the cas is the is the thing mounted to the end on the intake cam? When I put the new timing belt on I put a screwdriver in the back of the block to assure the oil pump was in correct position, the arrows on cams, pump and crank were right, rotated it 6 times everything matched up. Put a timing light on it during the first couple startups and timing was good. What is involved with setting the cas timing, I don't have a manual?

 

[DeadlyScone]

thats a thermovalve. its not important, get a 3/8 bspt or even a ntp plug will work.

It is pretty important as it directly affects operation of the egr. Unless you have you're egr deleted/blocked off you will need a new thermal control valve.

Here is a vacuum diagram for federal emission vehicles.

As for the main issue, try working your way down some of these suggestions.

1. Use the check connector for the fuel pump and verify its working properly.
2. The MPI fuse and The CAS directly relates to the fuel pump operation so verify your ignition timing and that your MPI fuse has continuity.
- also what shape is your ecu in? Does the check engine light come on for a few seconds then turn off? leaky caps, ect?
3. Do you have a gauge on your filter/fpr that can tell you how much pressure you have?
4. How is your fuel filter looking? changed it lately?
5. IF you still have no pressure pull the vacuum line off your fpr and see if any fuel is pouring out of it.

 

[ScuzziOne]

Just realized you are talking about a 1G... kept looking at your 95 listed in your sig and getting confused...

Here's one site discussing it... it's a Laser, so it's got to be a 1G:

Engine Timing

Big thing to note is the grounding of the timing adjustment plug... if you don't do this, then you are not adjusting the base timing because the automatic timing advance controls are advancing the timing as you adjust the CAS so that you probably end up with full advance commanded just to get to base timing. This doesn't leave any room to properly advance the timing beyond base afterwards...

As for whether the CAS is out of phase or not, basically, you have to set the motor at TDC, remove the CAS and make sure the timing mark on the CAS rotor tab lines up with the timing mark on the CAS body, and then re-insert the CAS in the motor. Since this is more or less just a tab inserted into a symmetrical slot in the intake cam-shaft, it is possible to accidentally insert the CAS sensor shaft tab into the camshaft 180 degrees out of phase. Must admit that I don't know exactly how the motor would behave if this is the case, but I'm pretty sure you can dig up descriptions online from other folks who have done it...

Oh, and according to my 92 service manual, the timing adjustment wire is YR (Yellow with Red Marking)... anyone able to verify this is the same for a 91? Should be on the firewall where they show it in the link with a latching cap on it that you'll have to remove to get to the pin located at pin 1 of this two pin connector body. Believe mine is kinda tucked up in the wiring harness bundle, so look carefully...

Just for reference, here's a thread discussing possible CAS out-of-phase issue:

http://www.dsmtuners.com/forums/newbie-forum/259825-crank-angle-sensor-out-phase.html

Good Luck!

 

[skapegoat]

I grounded the timing adjustment plug and adjusted the cas to 5 btc. motor still shuts off a couple seconds after starting. I also noticed a click under the dash right before it dies. Guess now I need to find out how to read trouble codes. I can't really find anything in the search about it. Anyone have link?

 

[ScuzziOne]

http://www.dsmtuners.com/forums/articles-tuning-ecu/319844-1g-code-reader-cel-code-reader.html

 

[pauleyman]

Check your ECU. The click you hear is the MPI relay shutting off. That controls your ECU and your fuel pump. You've got an electrical issue somewhere.

 

[skapegoat]

I have a ecu in my parts car would I be wasting my time switching them?

The only code being put out is fuel pump. When I put the parts car tank and pump in I looked the pump over and it looked good. It flows fuel. Is there a fuel pressure sensor that is not sensing fuel pressure?