1991 dodge spirit R/T problems while running!

[zimbo]

Can't rev past 4k RPM and has a rough idle. sometimes wants to die.. works fine on startup but after startup it revs by itself from 1300 - 2200 (different each time) and then has a rough idle and can not rev past 4k RPM.. there is no resistance in revving it.. but if i push the pedal down to rev it past 4k it just wants to die. I made a video and checked for codes in the video. Any ideas?
http://youtu.be/Mdh9PNCAjWE
Ignore my comments about the exaust.. it only did that 1 time when i first revved it to 6kRPM and blew out the rust and stuff in the exaust.

[zimbo]

I looked at some past posts on here and I'm going to check all my Vac lines and check fuel pressure.. I just replaced the fuel pump and did jackson's mod and a new timing belt with correct tension and tensioned it the way Jackson reccomended.

I'm going to reset all codes then do a run cycle and see what codes come up then.. I think it has some old codes left there. Just saw that the idiot who owned it last had the # 1 & 4 spark plug wires crossed in the coil. so #1 was in 4 and 4 was in 1. i fixed that and that helped but it's still got a really rough idle and will start just fine and work correctly for 10 seconds or until i rev it to 6k.. then it goes back to rough idle and won't rev past 4kRPM

I'm at a total loss here.. Later today I'm going to have my friend who works heavyline at the ford dealer drop by with a few universal tools and check some of this stuff.

[moe44688]

Okay I'm no TIII pro but my TIII car had the EXACT same problem. Dumbass PO had 1 and 4 switched, timing was off, etc etc.

Its a good thing your trying to fix the problem and not driving the car (I hope, my blew the head and over a year later I'm still putting the motor back in after a complete rebuild).

I would check the turbo while your at it. Mine was shot when it started to act up like your car. Still have no idea why it did it, but ended up blowing a channel in my head.

Redo the timing with correct tension, check codes, check vacuum leaks, check turbo, fix wires and see where that gets you. In the meantime some TIII guru will get on and give you some better advice!

[zimbo]

I retimed it when i had the belt off! I think it's a vac line somewhere.. probably related to the MAP sens.. I got the car for free.. I'm just trying to get it running correctly and then sell it ASAP before something goes wrong lol

[zimbo]

Made progress.. I found that the Vac line from the middle of the intake to the MAP sens was hanging and clogged with solid dirt on the end piece.. took the end piece off and cleaned it and put it on the map sens and that took away the rough idle but now it wants to idle at 2700-2900RPM... :| does not seem to miss or anything.. no engine codes either.. (flashed it after I hooked up that line) so the car sat for years without the air filter in the airbox.. does the throttlebody need to be cleaned? or would the MAP sens do this? becuase when i unplugged the same Vac line from the MAP sens it went right back to rough idle and threw a code 13 and 14. i plug it back in and it throws no codes and seems to run fine but the idle is stuck at 2800ish RPM. any ideas?

[NAJ]

If you have a rough idle you start with basics...

1)Compression Test
2)Cylinder Leakdown Test
3)Engine Vacuum(16-20" HG)
4)Cam Timing
5)Ignition System(Capable of 25 KV) and Plug Wear/Condition
6)Fuel Pressure
7)Injector Balance Test
8)Vacuum System
9)Air Intake/Exhaust Restrictions

[zimbo]

I tried most of that.. but when I plug that Vac line in it goes away... yet revs up to and idles at 2800RPM and stays there the whole time. even right when i start it it goes to 1100RPM and i can count to 0.40seconds then it climbs up to 2800RPM.. i can blip the throttle and rev it to 3300RPM but then the RPM slowly drops back to 2800.. runs smooth no miss and no codes either!? I can't figure it out unless it's barely on the egde of operating paramaters and isn't throwing a code witch i find hard to believe.. I'm off to work now but I'll post a video of what it's doing later tonight! Thanks.

[NAJ]

High idle is going to be caused by a vacuum leak, AIS circuit problem or TPS closed throttle voltage is too high.

[zimbo]

If I had to guess it's probably a Vac leak or TPS

[zimbo]

Started it and let it warm up today, and it was at it's retarded idle speed.. (2800RPM) and i rev it to like 4500RPM and then it drops to 1800RPM then to 1500RPM and then goes up to 2kRPM and just keeps fluxuating from 1500 - 2100ish RPM at idle.. I restarted many times and flashed the computer and it's still doing this.. no codes still either. when I put it in gear (wow it finally moves) and go fast enough in first for the engine speed to be over 2200RPM it wants to rev back up while in gear and idle at 2800 - 3kRPM.. so it wont engine brake at all.. as I went up my driveway i shifted into 2nd and it stays around 1100 - 1200 and runs nice and smooth but still wants to pull by itself. I made a video on my phone that I'm uploading now, the quallity probably sucks but it shows what it's doing it seems like it's trying to rev back up to 2800RPM then it gets cut off.. then trys to rev back up and gets cut off.. at least thats what it sounds like from the exaust.

[zimbo]

1991 dodge spirit problem #2 - YouTube

This has to be vacuum leak.. I'm going to get a tool to test it tomorrow.. what should it be at? 17ish?

[NAJ]

Normal engine vacuum should read 16-20" HG and stay steady.

[zimbo]

I got around to this today.. Vacuum was surging from 8 - 15 HG and the engine is in time. any hints on hunting down the problem rather than buying all new lines or a box?

[zimbo]

plugs look like it's running rich smells like it also..

[zimbo]

Here is what it seems to be doing now. I start it and it revs up to 1800 - 2100RPM and stays stady for around 3 - 15 seconds then starts to idle surge from 1500 - 2100RPM like in the video above.. when the vechicle is warm it just goes right to idle surging at startup. The cams and crank are in time

Could it be anything else other than vacuum?

This thing is really getting on my nerves and I need to get it done soon. :(