Posi's Do-over

Time for a little update. Got the new manifold installed and started the Jeep up today. Tried several things the tech guy at Retrotek told me to do and it still ran like krap. I called Retrotek again and talked to a different tech guy. In the course of the conversation I mentioned the trouble I was having with the intakes leaking coolant. He asked me if any if it got into the exhaust system, to which I said "heck ya!" He told me that coolant will kill an O2 sensor as quick as running leaded gas will and that a dead O2 sensor will cause the symptoms I was describing to him. Basically the laptop was telling me the Jeep was running extremely lean, but my nose was telling me it was running extremely rich. So, off to Summit Racing at the crack of dawn (well, 8am anyway) to get a replacement sensor. This would explain a lot of why it's been running so bad. It was actually running pretty good when I first fired it up, just idling too high. But it got progressively worse after the initial startup. I looked back at the photo of the first manifold (top of this page) and could see that it was spewing quite a bit of coolant into the cylinders. So, I may have found the culprit. Update tomorrow.

 

make sure to back charge Offy for the sensors, I bet they would pick it up to make things MORE right with you.

 

No worry, Warloch. At least it appears that this manifold doesn't leak. If you need to talk to anyone at Retrotek about your FI, ask for Doug.

 

I sure hope you found the problem John, best of luck!

 

OK, I put the new O2 sensor in today and got the Jeep running a lot better. I was actually able to drive around town today. The idle is still high and it's fluctuating rpm's at idle. Smooths right out when I give it some pedal though. I haven't dialed in the timing yet as I need to get the idle down around 600 rpms first. Hopefully I'll get it all dialed in tomorrow. I am happy with the way it handles on the road. Not as much body lean as I expected on the curves. Pretty much like it was with the soft-ride springs I used to have in there. I have a little more travel in the brake pedal than I like, not sure what's up with that, I may try to bleed them again, MC too, although it doesn't feel like air in the system. I may just need to adjust the piston rod coming off the brake pedal.

 

I was thinking about the EFI. You may want to ask retroteck if the IAC still is in play after the engine is warmed up. If it is this could also be what is causing the fluctuation. If you are able to close off the IAC and get a smooth idle, then you can adjust your timing. Depending on how your engine starts, maybe you could take the IAC out of the equation permanently. May not be perfect, but it would be much better than what you have going on right now.

 

Hey Ryan, regarding what you said about the oddfire tach signal potentially causing the pulsing at idle. I told a big lie to the ECU and told it I have a V8. All of a sudden the engine smoothed right out and quite shifting between idle and decel mode. I'm still idling a little fast, but not too bad. Around 700 rpms. Telling it I had a V8 also caused it to run rich, but I was able to adjust that in the fuel wizard menu. After I switched it to V8 I went to fill up the fuel tanks and the Jeep refused to start. I mean NOTHING. I assumed it was because I changed it to 8 cylinder. I plugged the laptop in and changed it back to 6 cyl and it started right up. Got it home, changed it back to V8 and it started right up. In fact it started up another 10 times without a hitch. That's a little scary. I'm wondering now if I have a little electrical gremlin in the ignition system.

 

I wouldn't say you have an electrical gremlin.....keep driving and see what happens. Did you have spark? Switching to V8 probably changed the way the fuel delivers at idle and sounds like it helped smooth out the flow of fuel. The computer doesn't know or care if it the settings are for V6 or V8. As you found out, the fuel requirements are greater for a V8 and so you had to adjust your fuel tables. You would have to do the same thing with a crank sensor.....with that you could use a V8 or V6 crank sensor. You would just have to adjust your fuel table accordingly. If the fuel injection was port and sequential, then you would have to worry about the fine details, but with throttle body, it doesn't matter as long as the fuel it gets is right for a certain engine speed. Hope this helps. Glad to hear you are on your way

 

Yup, Don. It sounds just like that!

 

I don't understand why it's running better, I just know it is running better. I'm going to have to drive it with the laptop plugged in so I can monitor the air/fuel ratio at different rpms and under load in real time. As for not starting, it acted like no spark. However I didn't listen for the the fuel pump to kick on when I turned the key. If it happens again I'll be more observant.

 

Good news on getting it to run better.

 

Sounds like you are making progress, good luck and congratulations

 

OK, I think I figured out the no start issue. It appears that I have the fuel pump on a circuit that goes dead when cranking. No big deal if I let the pump pressurize the system sufficiently before I crank it. But old habits die hard and I think I just jumped in the Jeep and hit the key without giving the pump enough time to bring the lines up to pressure. It won't start with less than 45 psi to the TB. Hopefully I'm going to actually wheel this thing over the weekend.

 

Ya, thats great news posi! Great to hear its up and running. Congrats and good luck this weekend!

 

Gald to hear you figured out the no start issue. I hope the jeep is running well and does well on the trail this weekend. Do you plan on leaving the wiring for the fuel pump the way it is?