Strange idle problems/ Possibly starter problems

[mrjustinhead]

I've got a 1990 5.0 5 speed.

Okay, first the problem with what i believe is the starter. When i attempt to start my car sometimes, it turns but it doesn't catch and turn over. It can do it many times sometimes. I've been told that the starter may be missing teeth, or something..

Second, for example today i was driving in 4th gear at about 55. I shift into neutral and roll up to a stop sign. the rpms stay at about 2000, a little above and just idle at that. i can press the gas and it just goes up then idles at the same rpm again. When i put it into gear and start letting of the clutch and pressing the gas it drops back to normal rpm and runs fine.

Any help with these problems would be much appreciated.

Thank you,
Justin

 

[whtpny]

Sounds like a bad starter. Take it out and go to local parts store and have it tested.

Second problem: I would start with checking all the idle circuits. Idle Air Control Valve, Clean your MAF, Check voltage to your TPS, Clean all electrical connections.

Get Jrichker to chime in with some input

 

[mrjustinhead]

thank you very much, anything else anyone else knows is also very much appreciated

 

[jerryD]

sounds like the bendix drive is going out on the starter. have to get a new one. can't help with the idle prob. sorry.

 

[HISSIN50]

Just so we are on the same page:

turns over: the motor is being cranked by the starter (whir whir whir).

catch: the motor turns over and starts.


if nothing (at all) happens when you try to start, i would check primary electrical circuits (battery cables, etc). a bad ground can allow one to try to crank the car and get nothing. then after doing this a few times, it will start cranking (whir, whir whir).

if the starter makes some funky grinding noise, then i like Jerry's idea. bad teeth on the ring-gear or a flat spot on the starter can do it (just like Jerry said).

good luck.

 

[90mustangGT]

The starter definatly has issues. It is working but not engaging. No real cure but to replace it, or rebuild it.

The Idle problem it's hard to say. First of all, check to see if the throttle cable is binding, then check for carbon buildup in the TB. Go ahead and clean it out, spray the cleaner (throttle cleaner) into the IAC holes. If it continues, try tapping on the IAC with a screwdriver or small hammer and see if this effects the idle. Try it on the EGR valve as well. Then, check TPS voltage and set it to .9 - .998. Check for the vaccume leaks and if this is all good, pull codes. It sounds like the ECU is trying to compensate for something. If this does not work, come back with the results of this.

 

[65falcon]

exact same prob

I'm having the exact same problem as you. I also drive a 1990 5.0 5-speed. Have you run a code scan?

I think it is related to bad electrical connections, as I am pulling a few different codes leading me to believe this.

Codes:
32 (egr low voltage)
67 (a few things, however other threads have linked this to bad circuits)
63 (tps low voltage)

I also pulled 33 and 31 before, and ended up replacing the EGR valve and position sensor.. probably a waste of money though now that I'm seeing voltage codes poping up.


Unfortunately I'm not sure where to start checking wires, grounds, etc. I looked at my wiring diagram and there's a 'sensor control feed' which attaches to both EGR and TPS...???

 

[HISSIN50]

Where did the original poster go?

Falcon, if one has the trans in gear while running codes, 67 will be spit out.

Jrichker has some awesome posts about your codes - even simpletons like me understand how to test the circuits. Might be worth searching his posts for those.

good luck.

 

[Stangtamer]

hey bro, also check your alternater...many times if the alternater is going out, computer tells the engine to speed up in order to compensate for lost voltage that the alternater is not putting out at the desired idle...check your alternator as well...good luck
-jeremy

 

[65falcon]

simple electrical system cleaning!

This was sent to me by fireguy50 over on corral, I'll be doing this tomorrow and I'll post results. We should both try this, let alone anyone with a high-mileage 5.0.

http://fordfuelinjection.com/index.php?p=85

 

[65falcon]

AhhhhhHa! Well that makes sense then, good one to know b/c a lot of ppl get that code. I searched some of his posts btw, haven't gotten time to read a ton yet but will return to them later tomorrow. Thanks!

Falcon, if one has the trans in gear while running codes, 67 will be spit out.
good luck.