Hey Guys,

Just freshly rebuilt my motor. I put everything back together, and got it started. Problem is, it starts slowly. For instance, I turn the key to crank, it'll hesitate, sometimes it would seem like it'd want to catch. I have to add throttle in order for it to actually start.

The car stays on, and hasn't died on me. I don't think there's any problem with the engine itself. I'm thinking it might be the timing. I currently have the throttle body idle screw set up so I idle at around 1100 rpms, would that be a reason why it takes so long to start up?

Could it also be a timing issue? If I swapped the wires to the two trailing coils would that cause it to be like that? or maybe the crank angle sensor plugs?

I also don't have the fuel atomization vacuum hooked up yet because I want to get a filter for it. Would that cause it to start like this?

My current mods:
Rebuilt motor
Garret T04Z Turbo
750cc/1200cc injectors
Vacuum is at around 18ish, so it's perfect
Fuel pressure is like 60+ can't remember exactly, but I know it was around 60-80
HKS Twin Power
Power FC previously tuned by Ray Wilson at PFS for a T04S putting down 420rwhp

Would a tuned map for race gas cause the timing to be retarded causing this problem? I'm not sure how tuning goes, but I'm about to read more in depth on it. In the future, I do plan to have a retune for normal 93 octane Gas

Please help, I'm trying to get things straight with me FD, all help is appreciated.

 

In general, new motors are a little cranky until they've broken in some. It might clear up. Also, it could be your coolant enrichment map - might be a little lean or rich.

Dale

 

ok, I heard it was supposed to start right up after first start and letting it stay on for like 30 minutes though? I've got like 3 miles on it right now, afraid to take it places because idk if sometimes it might not start.

Another thing, it seems like cranking the car really drains my battery.

 

So you tried the new plugs?

You forgot to mention that it runs really fat at idle. Made my eyes water.

 

oh, ya, thought I got everything =P Thanks for the back up alex.

The car also seems to be really rich (I have a wideband, but for some reason it's not reading anything right now) >.>

I put in new spark plugs, and attempted to start it hoping it would start right up, but it still didn't do anything. Stayed the same. I was running 9range spark plugs, but after changing, I had some 9s and 7s that I bought before that I haven't had a chance to use, so I used those.

Any other ideas? Would the tune for race gas cause the timing to be off?

 

Was the engine ported? If so what kind of port are we dealing with?

 

The ports were only cleaned and slightly polished. Nothing else was done.

 

Check your map sensor.

Check that your CAS are correct.

Set the PFC on its base map.

It could also be that your engine has not built enough compression to "sustain" itself. Let it run for a good 2 hours at 2k rpm.

 

Do you have an aftermarket FPR? If so, how did you set the fuel pressure? Here's a good guide:

https://www.rx7club.com/showpost.php...83&postcount=7

 

I have an Aeromotive FPR. Would the fuel pressure really cause it to have a hard time cranking though?

 

If you are running it too rich, yes, as you'll be practically flooding it.

 

I'm having a similar issue with my car after the fresh motor. I also did lower mileage coils. Sometimes it just doesn't feel like starting. Giving it throttle helps sometimes. If I wait a bit, it will eventually start.

I also wondered about the cold start ignition being too rich but haven't had time to figure out how to adjust that in the Power FC.

 

I know before, after I got tuned by Ray Wilson, I was showing maybe 9s or 10s on my wideband at idle after driving it for a little bit. I will try and adjust the fuel pressure!!!


What should idle sit at? 750rpms?

 

Did you remove your fast idle cam or ISC valve?

 

They are both still entact on the engine.

I was going to check the fuel pressure today, but it was cold as ***** and it's gonna snow tomorrow, so I don't think I'll be heading out there for a few days. I'll update a bit later =D

 

Ok, time to update this thread, today I set the fuel pressure to about 38 without vacuum. Hopefully that'll be ok. I haven't tried starting it up yet to find out what happens. I'll start it up tomorrow.

So I want to ask, is there anything else that could cause it to have a hard start?

Also, I notice that the lights and everything dims when I am cranking the car. All help is appreciated.

 

I actually have a question. Would setting the fuel pressure higher or lower cause the start up to be rich? I'm kinda confused about this, lol.

 

Higher fuel pressure = more fuel = more rich.

 

Thanks WaachBack.

Ok, so another update, lol. I installed a cat today to replace my midpipe and it definitely quieted down the car a lot but not as much as I'd like, lol, but w/e. Probably the exhaust leak =P


So here's the thing, after installing the the cat, I cranked up the car, still a hard start. I took a look at the PFC Commander and I noticed that the timing for leading and trailing were the same. It would move around -6 thru -9 and they would both show the same readings. I didn't think that was right, but since the car was on and I don't know much about timing, I just went outside to check for leaks, etc. Vacuum was around 360 - 400 mmHg (I think that's what it reads on the PFC)

Nothing. I go to the throttle body and rev it, but after I rev it a bit, it sorta hesitates and slumps and then dies. Great. I jump back inside the car and clutch in, start cranking the car and apply a little gas because that's the only way I can get it to stay on. The spark catches and the Tach revs all the way to 5k rpms, I left off the gas immediately and I take a look at the PFC. NOW the timing is different. Leading is like 4 and trailing is like -9 or something. I can't remember, it was either like that or vice versa. I notice the car is completely smooth. The vacuum is also above 400+ mmHG!!!

So after not driving the car for AT LEAST a year, I clean up all my tools (shove them inside the garage, lol.) I jump in and start reversing it out of my driveway. Well I reverse up this slight incline onto my street and I stall (**** NOT USED TO STAGE 3 CLUTCH!!!!!). Well, I think that it might be a hard start again so I pull the ebrake and crank the car giving it some gas, well, the car is at operating temps 170 degress farenheit, and it practically starts right up, slight hesitation but doesn't take too long to crank. I'm surprised by this.


Well, I was thinking, does anyone think there might have been a stuck seal or something? Why was the timing off at first then corrected after it died?

I had the PFC tuned at Peter Farrel by Ray Wilson before and am running on the map and timing I had for the T04S.



Can anyone tell me what might have happened and what might have fixed the problem? My buddy was telling me he thought the car was running on one rotor, well now it seems like it's running on both, so could it have been a stuck seal or something?


Thanks to all the people that have helped me thus far =D

 

Your timing isn't off and didn't correct itself, the values changed because your rpm went from 1000 to 5000. Timing changes with load and rpm, just like vacuum becomes more positive with rpm. I wouldn't worry about your timing right now

If you were running on one rotor you'd know it, the car would sound horrible and the engine would shake badly.

One thing I havent seen you mention---battery voltage. what is it, both before you start the car and when it's idling?

The car sounds like it needs a tune to clear up the problems you're having.

 

the starting battery voltage is at around 11.5 and after starting it, it's like 14s? I'd need to check tomorrow to make sure.

well, that's the thing. the car did sound horrible and the engine would shake a bit every now and then. I want to do break in miles on it first before I even think of taking it for a tune again, hahaha.

Well, the thing is after I revved it to 5000rpms the timing changed completely from what it was when I first started it and it was idling.

I think some of my words are jumbled so I'll redescribe what happened:
Start the car, timing at idle was at like -4 to -9. Both leading and trailing were the same
Rev the car and it dies. I restart it giving it gas and it revs to 5000rpms because of my input, but I immediately get off gas and it comes to idle at around 1000rpms. Timing is now completely different. Leading stays in the positives, trailing stays in the negatives.

I thought it might have made a difference =|

 

You were probably in a different vacuum cell so the timing was different.

If a seal sticks your vacuum will get pretty poor, like -200 to -250, but it's also pretty dependent on rpm.

I doubt it's the problem, but did you swap any engine hard parts on your rebuild?

 

same rotors, housings, crank, etc. so I'm pretty sure the balance is still there. I hope that's what you mean.

Vacuum cell? could vacuum cause something like that?

Also, my fuel atomization line isn't hooked up yet, could that be the problem? I was under the impression it only needed air and wouldn't have any other significance.

 

What wideband do you have? You said you have something wrong with it?

go to settings-->IGL screen of the commander. What are the timing values in the N1-N2, P1-P10 cell matrix?

Go to the water temp menu. press the next key. What are the values for cranking fuel?

 

I have the Innovative LC-1 with the XD-16 guage. I have no idea, but it's not reading. I think that the Oxygen sensor might be bad. It was working perfectly fine before.

Here's what I collected (none of the IGL or IGT values are negative):


IGL:
N1 N2
P1-3 3
P2-3 3
P3-3 3
P4-3 3
P5-3 3
P6-3 3
P7-19 19
P8-19 19
P9-19 19
P10-19 19

IGT
N1 N2
P1-3 3
P2-3 3
P3-3 3
P4-3 3
P5-3 3
P6-3 3
P7-14 14
P8-11 11
P9-10 10
P10-8 8

INJ:
Showed 100s on the N1 N2 and P1-P10 matrix

Water Temps:
80C 1.00 1.00
50C 1.07 1.01
30C 1.29 1.23
10C 1.57 1.5
-10C 2.01 1.87
-30C 2.01 2.87

Those are the readings I collected.