Very weird problem

[Jester73440]

Ok at the end of last year I bought this car(see bottom for specs please) and posted the problem. well I took some trouble shoot advice and we are still scratching our heads. Here is the deal the car will run for about 20-30 minutes and shut off. The car will not restart for about an hour and usually dies even quicker maybe 15 minutes.The check engine light is always on reason I'm thinking is the mass air meter is stock and the car has 24 lbs injectors so it is running very rich.

Here is what we have tried, we changed out the TFI module didn't work. We have changed the coil didn't work. The guy I bought the car from said he removed the MSD ignition box didn't work. You can hear the fuel pump turning on so we are not sure if it could be that.One thing we tried was spraying some starting fluid in the intake.It did turn over.So that got us confused on if it is spark or fuel we thought for sure it was spark but now we are not sure.So here is what we are going to try. Hooking up a fuel pressure gauge, putting in a different computer removing the msd box ourselves. After that we will really be scratching our heads again. I'd appreciate any input thanks
-Steve


Car sepcs:
1990 mustang
New ford racing 5.0 short block
eldlebrock performer heads
eldlebrock intake
MSD ignition box distrubtor coil
holly 255 in take fuel pump
24lbs injectors
Stock massair on the car but need to get my pro-m massair meter recalibrated
BBK headers into a basanni Xpipe in to mac mufflers
Car was switched from automatic to T5.
Almost everthing on the car is brand new less then 3k miles
let me know if i left out any information

 

[mnsports]

That sounds like a fuel pump problem. When they start to go bad, they will over heat and turn off, once they have cooled down they run until they over heat again, As the pump gets worse it will run less & less time.

 

[Jester73440]

That is very likely but two things turn me away from that when the car shuts off and won't start I still hear the fuel pump kicking on. also the fuel pump has less then 500 miles on it I know it could just be bad

That sounds like a fuel pump problem. When they start to go bad, they will over heat and turn off, once they have cooled down they run until they over heat again, As the pump gets worse it will run less & less time.

 

[HISSIN50]

Steve, checking FP with a gauge and retrieving codes would have been my first move. the pump can make all the noise it wants (matter of fact, they can get louder as they fail) but it might not flow.

have you checked for spark when it wont start? as long as you have a decent battery, starter interlock devices and starter, the motor will turn over (whir whir whir) - this will happen whether or not you spray ether into the intake.

if this is getting a little daunting, i would search for Jrichker's no start checklist. it is a very comprehensive list which is systematic.

good luck.

 

[mnsports]

That is very likely but two things turn me away from that when the car shuts off and won't start I still hear the fuel pump kicking on. also the fuel pump has less then 500 miles on it I know it could just be bad

I had a pump go bad in one of my cars and it to the same thing and they do get louder before they go.

 

[STINGER99]

i would also aggre with the pump as the sourse of your problem, and you say the pump has 500 miles on it, did you put it in or was it the old owner, hate to say it but some people would list new parts that don't exsist to sell a car. or it could be defective.

good luck with the car.

 

[Jester73440]

Well I plan too hook up a gauge this week to test it My friends and I thought if you hear it it is probably working. It is a new pump I bought the car from one of my best friends I helped him build some of it he got the 05 itch and I got this car for a good deal just bought it knowing it wasn't finished

 

[88GTtom]

did you check your timing...

 

[Scorcher2005]

did you check your timing...

bad timing can make cars run bad...but not cause problems like this.

 

[Jester73440]

Ok well we thought we had it but we don't. We hooked up a gauges its not fuel its spark for sure. Now here is what we have tried:
New TFI
New coil
took off the MSD box hooked up stock Ignition ( this made a big change and we thought we had it. Car ran smoother and instead of dying out after 30 minutes we are going around an hour.)
Now what would be shutting off the spark our next idea is a bad computer. The check engine light has always stayed on so we are unsure on what that maybe.When we tested the spark we tested from the coil so its not the distrubuter. Please help me out we our running out of ideas and its getting into the season. I went and got plates for the car today thinking we had it with the bad MSD.

 

[HISSIN50]

what are the codes?

good luck.

 

[jeffbigwood27]

Dude using mass air meter for 19lb injectors and you have 24lb put 19lb back in or get the correct meter. Might help...

 

[just4bob50]

you may have a bad alternator. If your alt is making less than 14 volts or worse yet 11-12 your car will run till the point that the battery voltage goes to low to keep the car running. after the car sets for a while the battery will tend to trickel charge it self allowing the car to start again only to repeat this process.

 

[Jester73440]

put on the 24lbs MAF and a bad alt was in my mind but when the car died today i tried jumping it with my chargers jump start. The original owner told me it was giving a lot of codes that some made no sense it was giving codes for like the o2 sensors and tps **** that is brand new. I need to get it metered tho just so I know

 

[jackchan]

ok here is something I ran across a few years back and it sound nearly identical to your problems. Turns out the computer ground wire screw was stripped out and the computer wasnt getting a good ground. The buddy of mine ruined a new engine trying to make it run before bringing the car to us (we use to have a mustang shop locally) we rebuilt the engine and still had the same problems, until we traced the grounding problem down.

check all your main harness and computer grounds.... it cant hurt! and hopefully it will cure your problem!
Jack

 

[vristang]

I hate to be a pessimist, but how is the oil pressure?

Years back I had a pick up that leaked oil BAD. When the oil level got low the pressure would still register on the gauge, but flow was not high enough. It didn't take long for the engine to seize. After the motor cooled, it would start back up. It was hard to trace the problem when the oil gauge still showed pressure.
Maybe a piece of gasket found its way into the pickup tube or into an oil passage somewhere, and is restricting flow.

I hope that you have enough good luck, so that this is not your problem!

 

[86droptop]

Its the pick up coil in the distributer. I had the same problem tried everything you did. had to replace the distributer, it was 70.00 at autozone

 

[2002BLGT]

another vote for the pickup coil , go the a local parts store and get a remanufactured distributor and put your new TFI on it and that should fix it ....

 

[jrichker]

Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great.

See http://www.troublecodes.net/Ford/
OR
See http://www.dalidesign.com/hbook/eectest.html for more descriptive help
OR
See http://www.mustangworks.com/articles/electronics/eec-iv_codes.html

IF your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.

Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

For those who are intimidated by all the wires & connections, see http://www.actron.com/product_detail.php?pid=16153 for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Walmart.

Or for a nicer scanner see http://www.midwayautosupply.com/detailedproductdescription.asp?3829 – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $33.

 

[Jester73440]

Well about the engine losing oil pressure the starter still spins the motor so i doubt its that. About the pickup coil would this pervent the coil from sending spark to the distributor? when we tested spark we did it between the coil and distributor and we got no spark