Pennock's Fiero Forum
  Technical Discussion & Questions
  Cranks but no start

Post New Topic  Post A Reply
Email This Page to Someone! | Printable Version


next newest topic | next oldest topic
Cranks but no start by wu-style
Started on: 12-08-2014 04:12 PM
Replies: 21 (422 views)
Last post by: Paul.S on 12-15-2014 12:04 PM
wu-style
Member
Posts: 118
From: Norway
Registered: Oct 2014


Feedback score: N/A
Leave feedback

Rate this member

Report this Post12-08-2014 04:12 PM Click Here to See the Profile for wu-styleClick Here to Email wu-styleSend a Private Message to wu-styleEdit/Delete MessageReply w/QuoteDirect Link to This Post
my gt woundt start, it just cranks ? i can smell gass, i have checked for spark whit a timing light and it works, i have checked the sparkplugs and they are wet and fine, it startet fine before, the problem came after i used a battery charge whit start booster mode....
can this be a fryed ignition module ?
IP: Logged
PFF
System Bot
Gall757
Member
Posts: 10622
From: Holland, MI
Registered: Jun 2010


Feedback score: N/A
Leave feedback





Total ratings: 88
Rate this member

Report this Post12-08-2014 04:17 PM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
Crank the starter and watch the tachometer. If it goes up to about 300 rpm, the ignition module is working. If the tachometer needle does not move, the ICM, pickup coil, or connectors and wiring associated with them is bad.
IP: Logged
wu-style
Member
Posts: 118
From: Norway
Registered: Oct 2014


Feedback score: N/A
Leave feedback

Rate this member

Report this Post12-09-2014 09:21 AM Click Here to See the Profile for wu-styleClick Here to Email wu-styleSend a Private Message to wu-styleEdit/Delete MessageReply w/QuoteDirect Link to This Post
i cranked the ignition today, and the rpm needel goes to 300rpm while cranking.. but still no start ??
IP: Logged
Gall757
Member
Posts: 10622
From: Holland, MI
Registered: Jun 2010


Feedback score: N/A
Leave feedback





Total ratings: 88
Rate this member

Report this Post12-09-2014 11:03 AM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
Primary ignition is OKay....

If you can make it run on starting fluid, the spark is good and your problem is fuel delivery. (too little or too much....the spark plugs should not be wet.)

Your difficulties sound a lot like this thread....

http://www.fiero.nl/forum/Forum2/HTML/134211.html

[This message has been edited by Gall757 (edited 12-09-2014).]

IP: Logged
jschmidt95
Member
Posts: 92
From: Farmington Hills, MI, USA
Registered: Jan 2013


Feedback score: N/A
Leave feedback

Rate this member

Report this Post12-09-2014 02:31 PM Click Here to See the Profile for jschmidt95Click Here to Email jschmidt95Send a Private Message to jschmidt95Edit/Delete MessageReply w/QuoteDirect Link to This Post
Gall757, Where would you start investigating if the tach doesn't go to 300rpm and you have already changed the ICM?
IP: Logged
Paul.S
Member
Posts: 107
From: Grand Rapids MI
Registered: Nov 2014


Feedback score: N/A
Leave feedback

Rate this member

Report this Post12-09-2014 03:10 PM Click Here to See the Profile for Paul.SSend a Private Message to Paul.SEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by jschmidt95:

.......Where would you start investigating if the tach doesn't go to 300rpm and you have already changed the ICM?

I'd start by testing the ICM in place.

http://www.fiero.nl/forum/F...2/HTML/134118-2.html

Look for the pic in the middle of that page for info on how to backprobe. Look further down for info on backprobing the purple/white wire from the ICM. Got pulses? Suspect the ECM. No pulses, check everything on the other side of the ICM, then have the ICM checked at a parts store. -Paul

------------------
1988 Fiero Formula 25k miles, garaged since 1988

IP: Logged
Gall757
Member
Posts: 10622
From: Holland, MI
Registered: Jun 2010


Feedback score: N/A
Leave feedback





Total ratings: 88
Rate this member

Report this Post12-09-2014 06:21 PM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by jschmidt95:

Gall757, Where would you start investigating if the tach doesn't go to 300rpm and you have already changed the ICM?


If the tach is not moving, primary ignition is to blame. The components in the primary (low voltage) ignition are: ICM, pickup coil, part of the ignition coil, a magnet, and the connectors and wires for all that stuff. Too many ICMs are bad when new, so you should test it. With cars this old, corrosion can be anywhere, so even screws and pins should be cleaned.

Edit: You can test the ICM with the Paul.S Backprobe method, or take it to a parts store that has a tester, or throw another part at it.....because it's about $20 on e-bay....but I avoid the Big Box Store house brands...... Delcos seem to be a little more reliable.

[This message has been edited by Gall757 (edited 12-09-2014).]

IP: Logged
wu-style
Member
Posts: 118
From: Norway
Registered: Oct 2014


Feedback score: N/A
Leave feedback

Rate this member

Report this Post12-11-2014 02:30 PM Click Here to See the Profile for wu-styleClick Here to Email wu-styleSend a Private Message to wu-styleEdit/Delete MessageReply w/QuoteDirect Link to This Post
i cranked her today whit a timing light. found out that there was no spark at all. later when i tryed the spark was there. and then it just went out again. it seems like my spark comes and goes like it wants..... ?
IP: Logged
wu-style
Member
Posts: 118
From: Norway
Registered: Oct 2014


Feedback score: N/A
Leave feedback

Rate this member

Report this Post12-11-2014 02:50 PM Click Here to See the Profile for wu-styleClick Here to Email wu-styleSend a Private Message to wu-styleEdit/Delete MessageReply w/QuoteDirect Link to This Post
i allso found out that the conector to the cold start injector was not in place.
but now the car missfires when i crank. starting to shot flames and make me losing my hearing....
IP: Logged
Gall757
Member
Posts: 10622
From: Holland, MI
Registered: Jun 2010


Feedback score: N/A
Leave feedback





Total ratings: 88
Rate this member

Report this Post12-11-2014 08:31 PM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by wu-style:
it seems like my spark comes and goes like it wants..... ?


If it is wet where you are, the spark plug wires may be arcing and not firing the plugs.... when it is dry, things go back to normal. New spark plug wires will fix that.
IP: Logged
wu-style
Member
Posts: 118
From: Norway
Registered: Oct 2014


Feedback score: N/A
Leave feedback

Rate this member

Report this Post12-12-2014 06:43 AM Click Here to See the Profile for wu-styleClick Here to Email wu-styleSend a Private Message to wu-styleEdit/Delete MessageReply w/QuoteDirect Link to This Post
they are allmost new. only 2 weeks old. i havent have the chanc to try the car whit them becsuse of the snow. they are sti wires from fierostore.
IP: Logged
PFF
System Bot
wu-style
Member
Posts: 118
From: Norway
Registered: Oct 2014


Feedback score: N/A
Leave feedback

Rate this member

Report this Post12-12-2014 07:16 AM Click Here to See the Profile for wu-styleClick Here to Email wu-styleSend a Private Message to wu-styleEdit/Delete MessageReply w/QuoteDirect Link to This Post
wires, sparkplugs, distributor , cap , rotor , pick up coil , icm and the coil.

All this things are new , and only 2 weeks old , and never been road tested before. only idling tested.

one of the screws that holds the icm in place is broken. Are they some kind of grounding screws maybe ?

[This message has been edited by wu-style (edited 12-12-2014).]

IP: Logged
Gall757
Member
Posts: 10622
From: Holland, MI
Registered: Jun 2010


Feedback score: N/A
Leave feedback





Total ratings: 88
Rate this member

Report this Post12-12-2014 08:59 AM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
Yes. They need to be clean and tight to ground the ICM.
IP: Logged
Paul.S
Member
Posts: 107
From: Grand Rapids MI
Registered: Nov 2014


Feedback score: N/A
Leave feedback

Rate this member

Report this Post12-12-2014 09:16 AM Click Here to See the Profile for Paul.SSend a Private Message to Paul.SEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by wu-style:

wires, sparkplugs, distributor , cap , rotor , pick up coil , icm and the coil.

All this things are new , and only 2 weeks old

With all that replaced it doesn't leave much room for ignition problems.

 
quote
i cranked her today whit a timing light. found out that there was no spark at all. later when i tryed the spark was there. and then it just went out again. it seems like my spark comes and goes like it wants..... ?

Are you sure the timing light is reliable and was connected well each time? I'd go old school and test again with an old spark plug, and also take a close look at spark strength while testing.

If you really do have an ignition problem, recheck everything and also look for bad connectors and corroded wires.

 
quote
one of the screws that holds the icm in place is broken. Are they some kind of grounding screws maybe ?


Not only for electrical connection, they hold the ICM heat sink in contact with the aluminum mounting plate in the distributor for cooling. Without heat sink compound and good contact with the plate the ICM can burn out in a hurry. If it has been like that for a while perhaps that was the start of your troubles. Fiero ICMs have a reputation as being fragile and flaky. Without good cooling perhaps the little use the new ICM has had was enough to cook it -Paul
------------------
1988 Fiero Formula 25k miles, garaged since 1988

[This message has been edited by Paul.S (edited 12-12-2014).]

IP: Logged
wu-style
Member
Posts: 118
From: Norway
Registered: Oct 2014


Feedback score: N/A
Leave feedback

Rate this member

Report this Post12-13-2014 04:26 PM Click Here to See the Profile for wu-styleClick Here to Email wu-styleSend a Private Message to wu-styleEdit/Delete MessageReply w/QuoteDirect Link to This Post
i was soldering some wires on rhe tps sensor ( 4 plugged conector ) right before this problem. can that be the problem ? im thinking bad soldering on one of the wires or ??
IP: Logged
wu-style
Member
Posts: 118
From: Norway
Registered: Oct 2014


Feedback score: N/A
Leave feedback

Rate this member

Report this Post12-13-2014 04:59 PM Click Here to See the Profile for wu-styleClick Here to Email wu-styleSend a Private Message to wu-styleEdit/Delete MessageReply w/QuoteDirect Link to This Post
another thing im thinking is strange. is that on the 2 pin conector to the ecm i have power on bouth ? isnt it so that one wire should have power and one should be ground ??
IP: Logged
Gall757
Member
Posts: 10622
From: Holland, MI
Registered: Jun 2010


Feedback score: N/A
Leave feedback





Total ratings: 88
Rate this member

Report this Post12-13-2014 06:49 PM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by wu-style:

i was soldering some wires on rhe tps sensor ( 4 plugged conector ) right before this problem. can that be the problem ? im thinking bad soldering on one of the wires or ??


or.....? Right wires on the right spot in the connector? Bad connection? pin in a wrong location? Why did you need to solder on the TPS? Did you heat up the TPS?

[This message has been edited by Gall757 (edited 12-13-2014).]

IP: Logged
wu-style
Member
Posts: 118
From: Norway
Registered: Oct 2014


Feedback score: N/A
Leave feedback

Rate this member

Report this Post12-13-2014 07:59 PM Click Here to See the Profile for wu-styleClick Here to Email wu-styleSend a Private Message to wu-styleEdit/Delete MessageReply w/QuoteDirect Link to This Post
because the owner before me had repaird it whit some crapy cabelshoes. so i soldred it just to make sure it was a good conection.
IP: Logged
wu-style
Member
Posts: 118
From: Norway
Registered: Oct 2014


Feedback score: N/A
Leave feedback

Rate this member

Report this Post12-13-2014 08:01 PM Click Here to See the Profile for wu-styleClick Here to Email wu-styleSend a Private Message to wu-styleEdit/Delete MessageReply w/QuoteDirect Link to This Post

wu-style

118 posts
Member since Oct 2014
im pretty sure the wires are on the right location. i was cutting and soldring one wire at time.
IP: Logged
Gall757
Member
Posts: 10622
From: Holland, MI
Registered: Jun 2010


Feedback score: N/A
Leave feedback





Total ratings: 88
Rate this member

Report this Post12-13-2014 09:19 PM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
OK...well back to the ICM then....do you think the screw has been broken for a while? You should probably have an extra ICM anyway....
IP: Logged
wu-style
Member
Posts: 118
From: Norway
Registered: Oct 2014


Feedback score: N/A
Leave feedback

Rate this member

Report this Post12-15-2014 10:22 AM Click Here to See the Profile for wu-styleClick Here to Email wu-styleSend a Private Message to wu-styleEdit/Delete MessageReply w/QuoteDirect Link to This Post
ok, so the car fired up today it was to wide sparkplug gap that was the problem, sice my car is heavely rebuild, and build for dragraceing i cant use the orginal sparkplug gap, because its getting alot more fuel than orginal. i had to take them down to 0,38 to make her start.
IP: Logged
PFF
System Bot
Paul.S
Member
Posts: 107
From: Grand Rapids MI
Registered: Nov 2014


Feedback score: N/A
Leave feedback

Rate this member

Report this Post12-15-2014 12:04 PM Click Here to See the Profile for Paul.SSend a Private Message to Paul.SEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by wu-style:

ok, so the car fired up today

Glad you got it fixed.

 
quote
sice my car is .... build for dragraceing i cant use the orginal sparkplug gap, because its getting alot more fuel than orginal.

That would explain the wet plugs. You might want to disconnect the cold start injector or swap in one with a smaller orifice. -Paul

------------------
1988 Fiero Formula 25k miles, garaged since 1988

IP: Logged

next newest topic | next oldest topic

All times are ET (US)

Post New Topic  Post A Reply
Hop to:

Contact Us | Back To Main Page

Advertizing on PFF | Fiero Parts Vendors
PFF Merchandise | Fiero Gallery | Ogre's Cave
Real-Time Chat | Fiero Related Auctions on eBay



Copyright (c) 1999, C. Pennock