[moparfreak3]

I just recently completely rebuilt my 2.5 for my 89 es. Now that i have it in the car i have some major issues. It will overshoot its idle and die, lacks power, and eats fuel. I put my otc 4000 on it and looked at the values on my sensors and was a little dumbfounded to find that on the screen with the electronic advance it stayed at 000 no matter what the engine rpm or throttle. I had the scanner on my 87 Z and at idle the advance was 012 and it would move around with the engine rpm. But on this one it just stays no matter the dist position. When i unplug the cts to set the base timing it just dies it will not stay running at all. I changed out the hep with a brand new one, changed the throttle body with a known good one, changed computers, and the kicker I have no codes at all. And yes i did all the usual checks including the cam timing which was set perfect while it was on the stand. I do have a question however about the cam. The cam is an 88 tbi slider cam with the 668? n/a cam gear. Will this have a detrimental effect on the cam timing. If so i will swap the 89 turbo cam and turbo cam gear back onto it. Any input would be greatly appreciated.
Thanks in advance.
Kevin

 

[Sittn86]

It definitely sounds like a timing issue to me. I'd triple- and quadruple-check everything just to be sure. Do you have the proper followers for your camshaft installed?

 

[moparfreak3]

Yes the cam has the correct followers with it. I had to change the head completely b/c after i melted my piston the head was destroyed as well. The head is a turbo head I was using on an N/A car that i had sitting around. I am going to swap the cams tonight and reset the timing to see if maybe that will fix it. But the computer not giving any advance still confuses me. But after I try that I will let you know.
Thanks,
Kevin

 

[blown3.8]

id check the connections to the smec. check the rats nest of fusibles also you could also count the teeth on the n/a cam and see if they are the same as a turbo cam.

grabbing a roller cam is the idea. i have no idea what happens when the little plastic ring in the dist breaks either. but i have seen it happen. just ideas. timing does pop into mind tho also

 

[moparfreak3]

ok I checked the cam timing 3 times and got the ignition timing set dead at 12 degrees. I used the scan tool and checked the ais and that works fine. Injector pules width looks really high at idle though, it is at like 3.5 ms. I have only 12 in/hg at idle but the cam timing is correct. Could i possibly have 2 bad computers that both just so happened to work right the first time? I got a code for the cts so i changed it out with a brand new one. So i am now completely confused and distressed. Any other suggestions would be greatly appreciated.
Thanks
Kevin

 

[speeduphoria]

low vac at idle is normally either cam timing off, vac leak or AIS issue

 

[moparfreak3]

That is what i was thinking as well. So I guess when I get some time I will swap the cam out. But that still doesn't explain the dying when coming back to idle. Also a new symptom if i hold the throttle steady at like 2000 after a few seconds it will drop down to 1500 and then if you try to bring it back to idle it will just die.

 

[moparfreak3]

Ok swapped cam with 89 roller and reset the base timing. I now have 18 in/hg at idle and the injector pw is down to 2.3 ms at idle. I am still getting no advance according to my scan tool. If i rev it up it will not rev past 5 grand. It feels like it is under a load when it is not. Any ideas?
Thanks
Kevin

 

[phantomrt]

Is the exhaust clogged up? What is the fuel pressure at? Are the fuel supply/return lines switched? Does spraying water over the ignition components change anything at all?

I'm not sure why the total ignition advance isn't changing. I may have missed it, but are you setting the ignition timing with the CTS unplugged? Lots of people never unplug it before checking/setting the ignition timing and thus get it all F'ed up.

Either way, base timing doesn't affect the total advance readout on the scanner.

 

[moparfreak3]

water doesnt help base timing was set with the cts unpluged and the exhaust is just a downpipe the same that i was running before. Fuel press is perfect, lines are not switched. Everything is hooked up just as it was before i rebuilt the engine so I am really stuck right now.
Thanks
Kevin

 

[allmotor]

I just recently completely rebuilt my 2.5 for my 89 es. Now that i have it in the car i have some major issues. It will overshoot its idle and die, lacks power, and eats fuel. I put my otc 4000 on it and looked at the values on my sensors and was a little dumbfounded to find that on the screen with the electronic advance it stayed at 000 no matter what the engine rpm or throttle. I had the scanner on my 87 Z and at idle the advance was 012 and it would move around with the engine rpm. But on this one it just stays no matter the dist position. When i unplug the cts to set the base timing it just dies it will not stay running at all. I changed out the hep with a brand new one, changed the throttle body with a known good one, changed computers, and the kicker I have no codes at all. And yes i did all the usual checks including the cam timing which was set perfect while it was on the stand. I do have a question however about the cam. The cam is an 88 tbi slider cam with the 668? n/a cam gear. Will this have a detrimental effect on the cam timing. If so i will swap the 89 turbo cam and turbo cam gear back onto it. Any input would be greatly appreciated.
Thanks in advance.
Kevin

what does your timing light show for base timing? what does your scanner show for MAP vacuum? all vacuum lines connected properly and no leaks? I didn't know 1988 cams were sliders... all mine have been roller cams

 

[moparfreak3]

what does your timing light show for base timing? what does your scanner show for MAP vacuum? all vacuum lines connected properly and no leaks? I didn't know 1988 cams were sliders... all mine have been roller cams

Timing light is showing 12 for base timing. Scanner is now showing 18 in/hg at idle. All lines are connected correctly with no leaks. Don't know about the cam it is now an 89 roller.

 

[phantomrt]

What does fuel pressure do at 5000 RPM? Is it still okay then?