Yet Another Car Wont Start!

[kapkaniMD]

Hey guys I tried everything I could with out posting but the time has come. I have a '91 Turbo with: a Turbonetics 62-1 Dual-bearing turbo, Spearco Intercooler, Bosch Racing fuel pump, 550cc injectors, MAPECU, JE 7.5:1 pistons and JE rings, Crower Rods, alot of head work, and alot more things that I dont think is necessary to list. Anyways, I got the car this way and also without the ability to turn over. The car would crank but thats it. The previous owner said that he had just installed the new turbo and had only run the car with the turbo completely bypassed (something about a release on the wastegate) anyways he said he had been driving it for a while and then was working on it or something and i just never turned back on and etc.... I checked the coils and they tested fine so did the ignitor, the fuel pump definitely works, the plugs werent that old but were covered in crud so I cleaned them and put them back in. After the inspection, I put everything back and the car cranked exactly the same, However, Now it would get a putter in every once and a while and eventually turned into explosive backfires.?. The codes started at just a 24 and then showed a 14 after the backfiring. Oh and yes I checked the CPS wiring and it seemed fine to me

I have exhausted all my methods and now am seeking advice from someone more knowledgeable. Please help, THanks..!!

 

[Nick M]

14 means the ECU did not recieve a signal indicating the ignitor fired. If the ignitor does not fire, neither will the injector. Pull the EFI fuse for 30 seconds and see if you still have the 14.

You might have a wiring problem, and you are only getting an intermittent signal to start the injection and spark.

 

[madseacow]

but wouldn't it start with a missfire? I'd run down the list making sure you've got fuel/spark/compression, then the little things like your IAC... either the diaphragm or the gasket malfunctioning could cause it to not start.

 

[pimptrizkit]

i bet he pulled the cps and incorrectly re-installed it, start there and make sure thats put back in right,

i had it in close to 180 out and it did what you described.

 

[1988SupraDreams]

i bet he pulled the cps and incorrectly re-installed it, start there and make sure thats put back in right,

i had it in close to 180 out and it did what you described.

+1 for what this guy said. I've found this to be the problem on a lot of my friends supras when I go to fix them... Like JtWo's Supra.

 

[kapkaniMD]

The cars wiring is the biggest mess I have ever seen, there are wires not connected, cut, and even extra wires I have no idea what they are doing there, I can take pictures, but Im more interested in which wires are the most important and I can make sure those are intact. I can pull the CPS and inspect if that is what you think might be a problem as well

 

[1988SupraDreams]

If you can read a wiring diagram, rip all the extra crap out and put it back to stock. If you can't read a wiring diagram, try matching colors and splice it all together. When I pulled my Supra from a wrecking yard, it had this UGLY MESS known as a shock sensor/keyless entry/alarm system installed in which none of it worked, so I ripped it all out and just matched colors of wires and spliced it all back to stock. No problems yet other than my stock alarm, which is probably fried. There were 14 cuts into the harness (Just for the alarm)

And about the CPS, adjust it according to the TSRM.

 

[kapkaniMD]

If you can read a wiring diagram, rip all the extra crap out and put it back to stock. If you can't read a wiring diagram, try matching colors and splice it all together. When I pulled my Supra from a wrecking yard, it had this UGLY MESS known as a shock sensor/keyless entry/alarm system installed in which none of it worked, so I ripped it all out and just matched colors of wires and spliced it all back to stock. No problems yet other than my stock alarm, which is probably fried. There were 14 cuts into the harness (Just for the alarm)

And about the CPS, adjust it according to the TSRM.

the wiring is pretty much all stock i am just stating the crappy condition of the stock wiring that somebody screwed all up, Also what do you mean adjust the CPS, you mean just remove it and reinstall it correctly?

 

[jetjock]

That's what he means. Improper CPS installation seems to be a reoccurring problem with these cars. Odd considering it's a simple procedure and if one understands how the thing works one doesn't even need to follow the manual. While you're doing that carefully inspect the wiring on it.

You stated the PO had driven the car but done some work on it just prior to selling. It'd be nice to know what that work was. Code 14 may or may not be indicative of a CPS problem. It's usually not but I've seen times where it was due to the way the ECU processes error codes. Does the tach flicker during cranking? Since you messed with the CPS if you do get the car going be sure and check/set ignition timing.

 

[kapkaniMD]

Alright, I still havent checked out the CPS basically cause I am in medical school and have limited free time, the PO just told me that the backfire sounded like a air/fuel ratio problem???? that doesnt make too much sense to me, but it is a racing fuel pump and the car hasnt really been tuned according to him, I have the MAPECU that hasnt been installed yet, but I figured it had to be running for that to work properly also i was a little confused on the wiring because it is supposed to be a supra harness but it looks like there are loose wires on the harness that also have to be connected?? Can anyone shed some light on this as I am a beginner at tuning

 

[Nick M]

If you fill the exhaust with fuel, you will get a "muffler explosion". .

 

[kapkaniMD]

If you fill the exhaust with fuel, you will get a "muffler explosion". .

it did sound like an explosion, but wouldn't the car at least start before it started doing stuff like that, what does that mean then?? I tried turning off the fuel pump intermittently and starting the car and nothing

 

[Supraholic]

this may be a far stretch.. but did you check the fuel pressure regulator? could it be that the fpr diaphram is broken and u are leaking fuel into manifold through the vacuumm lines ? that would prevent from starting...

 

[kapkaniMD]

this may be a far stretch.. but did you check the fuel pressure regulator? could it be that the fpr diaphram is broken and u are leaking fuel into manifold through the vacuumm lines ? that would prevent from starting...

I can check that, but the car has a 3" exhaust straight from the turbo to the muffler, so I believe with 550 injectors and the car cranking that fuel could get in the exhaust without a specific leak, but I will still check

 

[xanatos]

Alright, I still havent checked out the CPS basically cause I am in medical school and have limited free time, the PO just told me that the backfire sounded like a air/fuel ratio problem???? that doesnt make too much sense to me, but it is a racing fuel pump and the car hasnt really been tuned according to him, I have the MAPECU that hasnt been installed yet, but I figured it had to be running for that to work properly also i was a little confused on the wiring because it is supposed to be a supra harness but it looks like there are loose wires on the harness that also have to be connected?? Can anyone shed some light on this as I am a beginner at tuning

If he's got a 255 LPH fuel pump, I'd start there. I know that with the J-Tube in place you could get a serious flooding issue if it's not bypassed. That could be what's mucking up your problem. Check to see if the J-Tube is still in line. If it is, I'd look into either performing a J-tube bypass or reaming out the restrictor in the J-Tube.

With the restriction the J-Tube provides (sort of as a backup FPR), you could be having a problem with not being able to return fuel back to the tank fast enough resulting in a flooding issue. A buddy of mine had a similar issue when he installed his 255 LPH pump and he had to do all sorts of playing around with his FPR until he could get it started as he kept running excessively rich.

BTW, does the vehicle have the stock or an aftermarket AFPR? You may also want to pull a plug and check for spark as well as examine the tips to see if they are soaked, or what other condition they are in. (i.e. Oily, blackened, white deposits, etc.)

/Just my 2 cents. I could be wrong.

 

[kapkaniMD]

Ok, let me begin, I will check to see the status on the cars J-tube could you first clue me in on its location on these motors. Im not sure if it has a factory AFPR but I will find out for you. Also I pulled the plugs they were pretty charred and had a little oil on them, I didnt see spark by just connecting the plug into a pulled wire, but I dont know if there is a better way to check, but I am assuming for it to backfire it has to have spark..??.. Either way that is why im posting on here cause I am looking for good info like I am getting, thanks

If he's got a 255 LPH fuel pump, I'd start there.
With the restriction the J-Tube provides (sort of as a backup FPR), you could be having a problem with not being able to return fuel back to the tank fast enough resulting in a flooding issue.

BTW, does the vehicle have the stock or an aftermarket AFPR? You may also want to pull a plug and check for spark as well as examine the tips to see if they are soaked, or what other condition they are in. (i.e. Oily, blackened, white deposits, etc.)

 

[kapkaniMD]

SWEET!!! Car is now running however the air/fuel ratio is crap, the car will not go over 3k rpm, and when it is idling if you hit the pedal the car will die. As I said I hooked up the mapecu and it says RICH in big letters however Im pretty sure it is running lean, I also mentioned I am a beginner and not too sure how to use the mapecu to adjust the ratio.... CAN SOMEONE PLEASE help me and let me know what to do, I also have a APEXi SAFC and a Halmeter AF30 guage that reads like 2 red bars on the lean side

Also, I have a HKS FCD that is connected to the APEXi SAFC but neither of the two are connected in the car, I am looking up wiring diagrams right now to properly connect them

 

[kapkaniMD]

Ok, after reading up a bit, everyone is saying not to use the FCD, however after reading my cars specifics what do you suggest, If I were not to use it, Do i still hook up my SAFC?? Someone please help cause I want to get this car running by the end of the month

 

[kapkaniMD]

UPDATE: I uploaded the Supra550ccinjector file onto the MAPECU that I just installed and the car seems to be reving pretty good now, before it would only rev to about 3000 and now it redlines easily, HOWEVER-it is still running rich and to top it off when I moved the car there is a oil leak, I think I know where it is coming from however The cause is the problem, IT appears that there is fuel or something getting into the oil and turning it to a murky grey thin liquid not to mention the dip stick is reading at the very top. I am going to change the oil, clamp the apparent leak, and bypass the J-tube to keep fuel pressure from building up. IF ANYONE!! has any ideas please let me know, everyone has been extremely helpful so far and I only need just a little more help

 

[kapkaniMD]

WTF!! I went ahead changed the oil, and it was definitely mixed with fuel. Ok no big deal right now, after the oil change I go to start it and it is doing the same thing as before, Just Cranking..... the problem the first time I believe was a little ground wire on the coil packs and as soon as we fixed it the car would start everytime. It has been about 5 days since the last start and the battery had lost its charged, but even jumping it would not help, PLEASE HELP!!