89 Colt GT problems

jeffball610 · Post by **jeffball610** » Wed Oct 17, 2007 4:46 pm

I bought this 89 Colt GT w/ 4G63t swap from a reliable source a little over a month ago. I've spent numerous days just gather little parts I was missing to make it a mechanically complete car. Now it's all together and it refuses to start. The engine will not turn over while the fuel pump is running, unless I crank it over and then plug in the fuel pump fuse. It still doesn't start. It is wired with a Walboro 255lph.

The MPI relay seems to be clicking every time. I went ahead and hooked up the SAFC (it was setup for one already) in case some wires were messed up. I did find one ground to the ECU that wasn't hooked up. Still won't start.

I put some fuel in the tank just to make sure there was plenty in there. Still won't start. Definitely have fuel, spark, and air. Compression looks good and the plugs smell like fuel and spark looks fine outside the motor. The SAFC won't read RPM while cranking over and neither will the tach. Not sure if it's supposed to. The CAS that was in the car had some bad wires, so I swapped in another one and still doesn't give me anything. I also checked to make sure it wasn't out 180.

I'm not sure where else to look. I've hooked up my Palm and MMCD, but it doesn't give me anything I can use. Is there anything other than CEL codes that will give me any idea what's up? I'm at a loss. I'll see if my friend comes up with anything. I really need this running and in road worthy shape by October 28th so I can drive to SEMA.

jeffball610 · Post by **jeffball610** » Fri Oct 19, 2007 8:04 pm

I've basically just narrowed it down to the injectors just not firing. There is resistance between the ECU connections and the injector clips. The MPI relay works, but not sure what else to check for there. The resistor seems to be good. The injectors themselves work and have the proper resistance. The thing just won't run.

I turned the fuel pump on and manually pumped fuel through the injectors with 1.5v and the car ran for about 2 seconds. It seems to run if there's fuel in there. However, the injectors just don't seem to work. What other leads can I follow? What else can I check? What are my alternatives to make it run? I really need some help.

Bill Hincher · Post by **Bill Hincher** » Fri Oct 19, 2007 8:24 pm

the ECU just provides ground to the injector, the power is supplied through the ignition switch and relays .

You might have injectors set up that would not require a resistor

Check the ohms on the injectors and make sure you shouldnt be running 12v instead of 6v through the resistor

Make absolutly sure that you have a ground between your engine, the frame and the ECU adding ground straps is always a good idea

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jeffball610 · Post by **jeffball610** » Sat Oct 20, 2007 10:07 pm

I'll try checking the injectors your way if this other way doesn't work. I can spin the Cam Angle Sensor by hand and if there is proper energy to the injectors, then I should be able to hear them click. It was also suggested that maybe there is a fuel issue. Either the fuel pickup has a leak and isn't providing the proper amount of fuel, or the stock Fuel Pressure Regulator is getting over run by the 255lph pump and the fuel trims are so far off it won't start. Hopefully I'll get this checked out tomorrow because it's supposed to get cold and possibly snow. I hate Colorado sometimes.

Bill Hincher · Post by **Bill Hincher** » Sun Oct 21, 2007 12:26 am

if the fuel pump is over running the stock pressure regulature it will create a rich condition

if there is a leak in the fuel pick up it will create a hard start ( prime time ) problem

from what you describe, the injectors are not allowing fuel to enter the system. either the injectors are not receiving enough voltage to open or there is not enough ground provided to the injector to open completely

You never mention what kind of fuel pressure you have, verify your pressure before you condemn the injectors

jeffball610 · Post by **jeffball610** » Sun Oct 21, 2007 5:10 pm

I don't have a fuel pressure gauge. I'm going to go ahead and order and adjustable fuel pressure regulator because I'll eventually need it. I just don't understand why having too much pressure would cause the car not to start, or even throw the CEL code. It's throwing a code for 41, the injector circuit. I would think you'd need an electrical problem to receive a code. I'll keep checking though.

jeffball610 · Post by **jeffball610** » Sun Oct 21, 2007 5:54 pm

I swapped out the entire fuel rail, injectors and FPR, but still nothing. I am getting power to the injectors and my logger is reading injector duty and injector pulse. I'm sure those readings just come from the ECU though. If there was a problem in the harness, where should I look? I already checked the wires from the ECU to the injectors (wires 51, 51, 60, 61) and there is resistance through those wires which leads me to believe they are good. I can't seem to find any good wiring diagrams that tell me where the other wires go, where the wires to the resistor come from, or anything that's helpful. I'm really at a loss here.

Bill Hincher · Post by **Bill Hincher** » Mon Oct 22, 2007 9:33 pm

you cant really get a handle on fuel injection diagnosis without a fuel pressure guage, maybe you could rent one

4g63mightymax · Post by **4g63mightymax** » Tue Oct 23, 2007 3:11 pm

How about checking the coolant temp sensor. If that is wired wrong or not hooked up, it makes starting a cold 4G63 a real pain in the ass, because the ECU doesn't know the engine is cold.
Is it hooked up properly?
-Jeremy

89coltgt · Post by **89coltgt** » Tue Oct 23, 2007 3:23 pm

If the temp sensor is not hooked up, the ecu sees that the engine temp is ~-17*F, and will run really rich and eventually throw a cel after the engine runs for a minute or so.

jeffball610 · Post by **jeffball610** » Tue Oct 23, 2007 6:18 pm

Wow! I feel stupid. Turns out I somehow mixed up the connection to the resistor box with the one on the TB. Same plug size, but different color wires. I kept looking at my 91 harnesses I have and they both have multi colored wires from the injectors to the resistor. The 90 style has all red wires. Yes, feel free to pummel me with retard comments.

The car runs, but is in limp mode due to a bad MAF signal. Just another thing I gotta check out. Probably just the wires from the SAFC mixed up or something.

4g63mightymax · Post by **4g63mightymax** » Tue Oct 23, 2007 10:04 pm

You aren't the only one that has mixed up those connectors.....

-Jeremy

kuroi · Post by **kuroi** » Thu Nov 01, 2007 2:19 am

HA! I couldn't get my 4G to start and finally realized there are two plugs that the CAS will plug into, and I had it plugged into the one that was.... wrong

coltboostin · Post by **coltboostin** » Thu Nov 08, 2007 3:22 pm

jeffball610 wrote:Wow! I feel stupid. Turns out I somehow mixed up the connection to the resistor box with the one on the TB. Same plug size, but different color wires. I kept looking at my 91 harnesses I have and they both have multi colored wires from the injectors to the resistor. The 90 style has all red wires. Yes, feel free to pummel me with retard comments.

The car runs, but is in limp mode due to a bad MAF signal. Just another thing I gotta check out. Probably just the wires from the SAFC mixed up or something.

Did that with my first GT when I was 17. Took me 2 hours and a Volt meter to figure it out.

jeffball610 · Post by **jeffball610** » Sun Nov 11, 2007 8:52 pm

Still don't have O2 volts after bumping the fuel to +40% on the SAFC. It will idle and drive, but with reduced power. I drove it about 2 miles around my neighborhood and got the FTLO to 118%. It seems like I'm not getting fuel from #2 or #4 cylinders. I turned them off from the Palm and nothing changed. However, when I turn #1 or #3 off, it tries to die. Right now it idles anywhere between 800rpm to 1500rpm. I'm not complaining, this is a step forward. Now I just need to find out why #2 and #4 are not firing, or at least firing correctly and fix my oil leak from the turbo drain at the oil pan.

Bill Hincher · Post by **Bill Hincher** » Sun Nov 11, 2007 9:32 pm

2 and 4 will be on the same firing order in the ignition coil
maybe something in the CAS or another plug swapped around, maybe a cracked coil

jeffball610 · Post by **jeffball610** » Mon Nov 12, 2007 11:35 pm

Actually 1 and 4 are on the same coil. I figure that's how the car is still running, the firing order isn't out 180 so it can maintain some momentum to keep running. I'll check it out tomorrow and see what's up.

jeffball610 · Post by **jeffball610** » Tue Nov 13, 2007 4:00 pm

I swapped out the #2 and #4 injectors cause they didn't seem to be firing. After I did that, the car ran great. O2 sensor started working and even drive pretty nice. I still have fuel trims at about +30% on the SAFC. Might be because I'm running a 1.6L Turbo ECU. I'll swap that out and see if it changes. That is, of course, after I swap the #2 and #4 injectors again. I shut the car down because my cooling fan rewire didn't seem to work and the car was running at about 220*. I let it cool down some and then it idled like crap again. Checked the injectors by pulling the plugs and also with MMCD and there was no change. I'll double check and make sure I can't hear them fire, but pretty sure they aren't working again. Might be the ECU messing things up, or perhaps the resistor pack. I guess I'll find out tomorrow.

idreamidrive · Post by **idreamidrive** » Wed Nov 14, 2007 11:35 pm

have you been over to 4g61t.com at all? its mostly ppl with turbo colts/mirages/summits/elantras over there

jeffball610 · Post by **jeffball610** » Thu Nov 15, 2007 4:43 pm

Yeah, I've been to 4G61t and other forums. I currently post on about 4 with my DSM stuff. Still can't get this figured out. I haven't had time in the past couple days to work on the Colt, but maybe some time this weekend will show progress.

jeffball610 · Post by **jeffball610** » Sun Nov 18, 2007 5:02 pm

Finally got it running ok. I went ahead and wired in some newer injector plugs and that seemed to do the trick. My fuel trims are still way off. It's been a while since I tuned a car so I could be wrong.

My SAFC is set at +40% for my low trim and I'm still getting readings from the O2 trim in the area of 140%. My short trim is setting at about 118%. I need to keep richening it up right? I can adjust my fuel pressure to get a little more fuel in there, but I'm not sure that's a good fix.

I have a 2G MAS and 450cc injectors with a Walboro 255. Last time I ran a 2G MAS I had 550cc injectors and had to lean it out a little. The 2G MAS is good for roughly 20% more air at the same reading as a 1G on the ECU right? If so, I should only need +20% on my SAFC right? I guess I'll get most of this figured out, but thought I'd ask for some input. Also, base timing on the car seems really high and that could be some of the issue. But now it runs and I can move on to other things.