mark kibort

Its when folks keep on trying to start it, thinking that the starter fluid will help it catch. it drys the cylinder walls out and it will sieze. 5 seconds, no, but any more than that, possibly. one thing nice about the Ljet systems, is that if it is working, the car will start, if it isnt, it wont. it may run rough if something is off like temp 2, injector issue, etc., but you dont need to coax it.
have you narrowed down the issue, or is it a damaged Ljet box?

Mark Anderson

The 1980 does does not have an O2 sensor output

PorKen

'80 L-Jet has an oxygen sensor input.

'80-'84 L-Jet brains are interchangeable for running. '80 probably has a slightly different fuel curve. '82-'84 brains have an extra injector pulse output @ pin 11 for the fuel consumption gauge.

USA '80 had less strict emission requirements than '81-'84, and so does not have an airpump. The distributor has a different ignition curve, and the fueling may be slightly better for performance than '81-'84.

UncleMaz

Thanks for that, I thought my air pump was deleted.

IcemanG17

Good news....IT WAS THE TEMP II......it was reading high...around 4.3k when it should be under 3k for the temp....we pulled it...engine would fire off the cold start..then die.....we "jumped" the temo II and it ran...kinda rough till it got warm...but once warm it ran like a champ....

I new one is on order....but we found a correct reading one off an Ljet volvo motor and installed it.....it reads properly and we set the ignition timing to factory spec....it was a smidge too high at 22' @ 3000rpm where spec is 20" @ 3000....at 22' degree's it was really dying past 5k...but the 20' made a nice flat power curve with our highest ever dyno # of 193.3whp....we did loose some torque but still have plenty....

The response of the engine is much improved and it just feels stronger......

mark kibort

what is with those lame curves! where is the RPM???? did you cut out at 5500rpm or something. Looks like its peaking out there and sure, it would be nice to run over the peak and down the other side for max power utilization, but running under it, only averages your power from 190 to 150, so 170 average is not bad.

vwdmc16

yeah for some reason we cant get the rpm to be printed on the paper. The software on the dyno sucks. But the run was from 2500 to 5650rpm by 5400 it really didnt want to pull much more, and there is NO reason to really hammer on this old engine just to get another hp on the screen. wouldnt it suck to throw a rod 4 days before the race, that could happen! it will be beaten plenty this weekend,


I tell you all this stress from it working and failing and deciding to work is just too much! i told you it wasnt the kill switch, which is working just fine BTW.

also finished the tranny oil cooler tonight, its a cleaned up 2nd gen RX7 oil cooler with the thermostat removed for more flow, mounted up front, it should get tons of airflow, these coolers are massively efficent. yes it will impede the radiators efficency somewhat but that wont be problem in the cool weather.

Now all that remains is a few trivial things but techncally it is ready for racing

mark kibort

cut a big hole where mine was in the hood. it will be good for some decent downforce up front, even without a splitter.

Yes, I get that it was not the kill switch. It just you were doing things last min an blazing new trails where things can go wrong. There is just a lot of knowledge here to set up things like that , along with comments of the drawbacks of things that could go wrong, or things to look out for. thats all.

looks like you got it all together. Told you it was probably the Temp IIl BTW!

mk

Andre Hedrick

I have a factory new one in the box.

IcemanG17

Andre
That is good to know.....luckily for us the one in the "estate" works fine...PM sent