evo626

I'll start with this I have used the search option but have not found the answer for my problem.

The engine and ecu..etc are from a 1997 I30T. They are in a mid-engined locost type car.

The wiring and engine have remained mostly stock. I cut out some of the heater control stuff but the engine harness is stock, minus a few extensions. The main difference between my car and a max is the fuel system. I have a fuel cell, with a 255lph walbro on it. It still has a vent, and all the essisions stuff is hooked up.

I don't have a fuel temp sensor. (If someone could tell me which wires to put a resister to fake a temp that would be helpful.)

Other than the fuel pump its all stock. The car will start but I have to mash the throttle and crank it over and over again. Sometimes it will run down the battery and I have to jump start it.

I replaced the crank and cam sensor with no change in the problem. I reworked some grounds and checked the injectors and coils for spark. All is good.

I ran the codes and got a P0180, fuel pump temp sensor, P0443 EVP Purge Control Valve and P1105 Manifold Absolute pressure sensor.

The car runs pretty good once it's started. The only thing I did notice was the fuel pump dropping resistor next to the fuel pump control module gets really hot. Like too hot to touch and that doesn't seem right.

Any thoughts on what else I can try?


evo

oldngivout

iTrader: (8)

Congratulations on a non-traditional engine swap. Since you are using the stock wiring and support for the VQ engine I suggest you read this:

http://forums.maxima.org/4th-generat...rt-signal.html

I would also strongly urge you get a 95 Maxima ECU to run this engine. It will eliminate the unnecessary evaporative emissions components that this particular "car" doesn't need.

DennisMik

iTrader: (2)

The fuel temperature sensor was part of the fuel tank sending unit. The connector on the fuel tank is a 4 pin connector. Pin 1 for sensor output and pin 2 for chasis ground. The wire color for Pin 1 output is pink/blue stripe. The wire goes to Pin 52 of the ECU. At 68 degrees Farenheit (20 C) the sensor resistance should be 2.5K ohm.

evo626

Thank you. I checked the 7.5 signal fuel and all is good. I really think the fuel pump drop resistor is part of the issue. When running it gets so hot it can't be touched. Any idea on how to bypass the resistor. It has a green/red wire coming from the fuel pump control module and a black wire ( I assume ground I'll test for voltage). Maybe the walbro is pulling too much voltage.

I'll put a resistor on the fuel temp sensor to fool the ecu.

Evo

evo626

I worked on it a bit this morning and found the map sensor p1105 had a fault in the wiring. Where it bends the wire broke and was getting intermittent power. I cleared the code, however now it shows as pending.

I tried using resistors for the p0180 code with no luck. I may pull the sensor out of a junk yard fuel pump and see if it will work out of the tank.

Evo

DennisMik

iTrader: (2)

Besides giving resistance values for the fuel temp sensor, the FSM also gives a voltage reading. At 68F/20C, the voltage reading at pin 52 of the ECU should be about 2.5 volts. At 122F/50C the voltage should be 2.2 volts.

The manual says to use the ground on pin 43 of the ECU. I don't know what difference there would be between using pin 43 or using chasis ground, but the FSM says use pin 42 for voltage measurement purposes.

This info is from section EC, page 190 of the 1997 Infinity I30 FSM.

http://boredmder.com/FSMs/Infiniti/I30/1997/

evo626

Thanks. I'm begging to think the hard start is fuel pressure regulator related. The starter is very strong and the only way to start it is to mash the gas. On most obdii cars this signals the fuel pump to stop because the car is flooded. I'll pick up a gauge and see what kinda of fuel pressure I'm getting.

I'm running a walbro 255 with a prefilter through 8an hose which reduces at the main (new) fuel filter to 5/16 hose.

Evo

evo626

I got the p0180 code to go away by using a few resistors to fake a target voltage. In this case 2.96. ( maybe not ideal but it cleared the code)

Now onto the p0443 And p1105. I found the evap canister purge valve was sticking and I put some wd40 in it to unstick the valve. Didn't clear the code but I'm sure it helped.

Next I took voltage at each of the 3 solinoids up top near the map sensor. Each on read .16v on the hot wire. 2 out of 3 connectors had frayed wire ends but voltage was consistant so I didn't fix those just yet. .16 seems low when the fsm say it should be a battery voltage, what am I missing here?

I only have 2 codes now and the car is still very hard to start. I checked and cleaned the crank sensor pos and found the connector housing was slightly cracked but it appeared the sensor still works.

Any other thoughts on the hard start. I didn't meant ion this before but the engine turns over very quickly when I try to start it.

Evo

evo626

Further research says it may be the starter not engaging as it spins really fast. May not be getting a good ground. I'm going to pull it and test and then add a ground wire directly to the starter.

Evo

FallenOne

iTrader: (17)

MOAR pictures please.

Product_Of_Korea

iTrader: (8)

This.........


and videos when she is up and running

evo626

I'll get some videos and pictures up. I took the starter out tested it, took it apart to make sure there were no wore parts and put it back in. Car cranks just fine (I can see the belts moving so I know it's turning over.)

I tired disconnecting the maf and there was no change. The car will start if I floor the gas and crank over and over but no start. Added extra gounds to the starter as well.

Reading some other treads and TSBs it appeared the engine harness could be the culprit. The area that goes over the right side (passenger) engine bay is known to have problems. I have found electric faults in the engine harness, cracked wires at connectors and I believe my best bet to fixing this is to pull the engine harness and take off all of the insulation, bit by bit and trace each wire to insure no bad spots. Seems like over kill but at this point I think it's my only option.

evo

evo626

Ok I checked the harness and it was fine. Next I took the starter apart and cleaned and lubed it. Works better than new now.

I found I can get the car to start with a bit of starter fluid in the tb. I'm a bit low on gas so I'll top it off and see if that helps. If not I'm at a loss.


Evo

DennisMik

iTrader: (2)

I wonder if the Engine Coolant Temperature Sensor (ECTS) is the problem. If it thinks the engine is hot, the ECU cuts back on the fuel injectors.

When you started it with the starter fluid, did you run the engine long enough for it to warm up? Then, with the engine hot, would it start by itself?

evo626

I warmed it up and turned if off. It had trouble restarting. I filled the fuel cell against and it didnt change the situation.

On that note, my radiator is behind the engine. The gauge says it is not over heating and works propery with the fans cycling.


Evo

evo626

Today I'm going to pick up a fuel pressure gauge and check fuel pressure. I am starting to think it has something to do with the fuel pump control module and the dropping resistor as the dropping resistor gets too hot to touch when it is idling.

Can I just rewire the fuel pump to get power from a relay and direct 12v from the battery?

evo

evo626

One other question, what does the start signal wire do? Does it signal the starter to start or the ecu to turn on the injectors or ignition.


evo

TheMaxima

Theres two temp sensors one just for the gauge cluster and one for just the ecm

evo626

I'll test the ecm sensor and see if it is bad. I've read this could cause a no start if it is way off.

evo

asand1

iTrader: (1)

I've read a recent thread stating that the start signal wire triggers the ecm to inrichen the A/F during cold startup.

evo626

Ok I did a fuel pressure test and found some interesting things.

Turn on ignition let pump prime: 15psi
If I let it sit with ign on it drops to zero.
Direct battery power to fuel pump, engine off 52psi.
If bypass fpmc but car is a bit easier to start. Turns over many times before starting but starts. Fuel pressure stays at 15 psi even with fpmc bypassed.

At pump 12.56v with 38 psi. 12.30v with ground for pump direct to chassis, how ever it is at 48psi. Direct battery to pump 13.42v with 48psi.

I think it is a problem with the fuel pressure regulator not keeping pressure after ign primes. 15psi is low and with It dropping to zero that seems like a problem.

Thoughts ?

Evo

Amerikaner83

iTrader: (17)

how long does it take for the pressure to drop ?

evo626

It drops within seconds. Do maximas have a check valve in the fuel pump or doe the fuel pressure regulator serve this purpose?

evo

Amerikaner83

iTrader: (17)

Pressure should hold and gradually bleed off...not quickly like that. I *think* the FPR serves the purpose of the check valve but I'm not sure.

DennisMik

iTrader: (2)

According to the FSM, fuel pressure should be 34 psi at idle and 43 psi with engine not running. The FPR uses engine vacuum to regulate pressure, so make sure the vacuum lines are OK.

Here is the text from the FSM:

3. Install pressure gauge between fuel filter and fuel tube.

4. Start engine and check for fuel leakage.

5. Read the indication of fuel pressure gauge.
At idling: Approximately 34 psi.
A few seconds after ignition switch is turned OFF to ON: Approximately 43 psi.

6. Stop engine and disconnect fuel pressure regulator vacuum hose from intake manifold.

7. Plug intake manifold with a rubber cap.

8. Connect variable vacuum source to fuel pressure regulator.

9. Start engine and read indication of fuel pressure gauge as
vacuum is changed.

Fuel pressure should decrease as vacuum increases. If results are unsatisfactory, replace fuel pressure regulator.

sergofast

iTrader: (22)

Wow...That not the pic i was expecting when I clicked on this thread. What is the car going to be used for?

What exactly is the Fuel pressure control module used for? It doesnt seam right that it gets that hot.

evo626

The car is a lotus 7 type chassis with a mid mounted vq30. It will be a street, strip, track car. But mainly for crushing.

I'll finish the rest of the testing but with the pressure dropping off so quick it seems the for has gone bad.

Engine off to ign on fuel pressure is 15 psi and drops within seconds so the car has to crank to build up pressure.

The fpmc controls the pump voltage through the ground at idle so it's not using as much fuel at idle. Pretty useless if you ask me. Grounding the pump directly and disconnecting the fpmc helped it start better as it gets more fuel pressure.


Evo

evo626

Ok a fuel pressure check today after starting the car. I got the car to start within a few cranks, still hard starting but not too bad.

I pulled the vac port, blocked it and put a vac-pump on the fpr.

At idle with no vac 58psi. With a -20vac it went down to 45ish psi, so the fpr is working with vac. It just bleeds off so dang fast when starting or turning off.

My fuel pump most likely doesn't have a check valve. If the check valve is suppose to be on the fuel pump I may just have to add one in line. Seems like the most reasonable solution.

evo

DennisMik

iTrader: (2)

I don't know about the check valve thing. If the fuel pump can maintain pressure when it is on and pumping, I wonder if a check valve is needed. What I question is the fuel pump pressure numbers that you posted. They were out of line according to the specs. While the FPR reacted to changing vacuum, it could still be bad, regulating at the wrong pressure. IIRC, there are 2 FPRs. Did you check them both?

evo626

From everything I've seen only one fpr. The reason for the high pressures is the 255 walbro. I read it would raise the base pressure. I believe since there is no internal check valve after it primes it is back flowing into the tank. I'll order an inline check valve and see if that helps.

Evo

evo626

Evo

evo626

Ok I got the check valave and installed it just aft of the fuel filter (can't install it at the pump unless I want to spend big bucks to do so). Anyway fuel pressure still goes down just as before.

This can mean only one of two things, the FPR has gone bad or an injector is leaking like bloody hell (unlikely because it would back fire like no other when starting.)

I have figured out how to get it to start on the 2nd or 3rd try. Ign on, ign off, ign on , ign off, ign on, pump gas pedle and then ign off and then back on, pumping gas and crank it while fuel pump is running. Tedious but it works and it starts right up.

evo

DennisMik

iTrader: (2)

I do wonder about the FPR being good my self. But your fuel pressure readings make me think that at one time it's bad and another time it's OK. When you jumpered power direct to the fuel pump, you had good pressure but letting the ECU (?) control it, the pressure was low. Without having enough experience with the FPR, I'm hesitant to make a definite statement.

The ECTS (Engine Coolant Temperature Sensor) that the ECU goes by is still a suspect. While the engine cold/engine hot starting test kinda says it is OK, that test still is not a comprehensive test. If the sensor were to be so radically inaccurate in "the engine is hot" direction, the starting hot/cold wouldn't show any difference. The FSM says to do a resistance test at specific temperatures. At 20C/68F resistance should be 2.1 to 2.9 Kohm. At 50C/122F, .68 to 1.0Kohm. At 90C/194F, .236 to .26 Kohm. I don't see anything (or I missed it) that you specifically tested the ECTS. Without removing the sensor, you could check the resistance with the engine cold. The temperature may be close enought to the 20C/68F to get a good enough reading as this is the "start in the morning" condition.

Reference section EC, page 124 of the 1997 Infinity I30 FSM.

http://boredmder.com/FSMs/Infiniti/I30/1997/

evo626

After much prayer, I found the fix for the last two codes (P0443 and P1105) It turned out to be a mismatched wire that I extended between F105 and M50. So now surprisingly I have 0 codes. Still a bit of a hard start but with no codes I can focus on other parts of the car.


evo

evo626

Ok I swaped the side I had the check valve on and it made it so the car started much faster. The fuel pressure still drops of but not as fast now. If I add another check valve on the fuel pump side that will fix the problem.

I looked at doing the FPR but that looks like a lot of work, taking off the TB and all that, and adding another check valve is a 10 minute affair. lol

Here is some video from in the car.

http://smg.photobucket.com/albums/v2...t=56ea5dd1.mp4

evo

evo626

Ok did some more work to test things out. It looked like the trans side ckps may have been bad. I added a 4 gauge ground to the 17mm bolt near the ckps with no change.

I pulled the ckps and cleaned it, no change. I did observe the ckps plug looked damaged and ordered a new ckps.

Installed new ckps and now it starts on the second start attempt almost every time, as long as you can catch it when the fuel pump is going.

I'm going to try jumping the fuel pump hot wire and then starting it. It looks like there isn't enough fuel pressure when the pump primes for 2 seconds. Fuel pressure only gets to 10-15psi. If I block the return it will go to 80psi. I know the pressure is not bleeding off through the injectors so I think a little longer priming will cure this issue.

evo

evo626

Ok the hot wire to the fuel pump didn't change anything.

I have zero codes, not check engine but it still has a bit of an issue starting up the first time. I hooked a timing light up and I get spark while it's trying to start so I can rule out the cam/crank sensors.

I cleaned the throttle body and that made it start up right away for the first few starts. It seems to have help make it start 1st or 2nd try. So I know I have spark and I know I have fuel, what in the air flow would cause it not to start right away? Should I try replacing the ects?

evo

evo626

I tried tarting the car today and it is still hard to start. I'm going to test the start signal wire and see if that is the issue. Maybe it's not telling the car to enrich the injectors for start up.

Evo

evo626

I found that the start signal is getting power at the fuse, but not at the ecu. My next step is to find where there is a break in the wire and fix that. This looks really promising that this is the issue.

evo

evo626

evo