NA8 1993 Model General Starting Problem

myredmx5 · Postby **myredmx5** » Fri Oct 03, 2014 10:53 pm

Finding it difficult to start the engine.

I have checked the following

ECU = changed
Fuel injectors = checked & cleaned
Fuel filter = changed
PCV = changed
Purge solenoid valve = checked it opens & closes
Coil resistance = checked
Spark plugs = changed
Spark plug leads = changed
Cam position sensor = changed for new one
Mass air flow sensor = checked
Throttle position sensor = checked
Injector relay = checked
Idle air control valve = checked resistance
Timing = checked
Fuel pressure regulator = Not checked
Oxygen sensor = Not checked
Clutch switch = Not checked

Not sure what else I can check!!

Any other ideas PLEASE

gslender · Postby **gslender** » Fri Oct 03, 2014 11:13 pm

Fuel pump

manga_blue · Postby **manga_blue** » Sat Oct 04, 2014 12:38 am

Run some jumper leads across from a car with a known good battery.

myredmx5 · Postby **myredmx5** » Sat Oct 04, 2014 12:44 am

gslender wrote:Fuel pump

Fuel pump has been tested but don't know if pressure is as per specications.

myredmx5 · Postby **myredmx5** » Sat Oct 04, 2014 12:45 am

manga_blue wrote:Run some jumper leads across from a car with a known good battery.

I used a battery which started my other MX

93_Clubman · Postby **93_Clubman** » Sat Oct 04, 2014 12:59 am

The following 'blackwire' in-fuel tank wiring connection issue began as increasingly hard to start until it would no longer start: viewtopic.php?f=55&t=46425

myredmx5 · Postby **myredmx5** » Sat Oct 04, 2014 8:27 am

93_Clubman wrote:The following 'blackwire' in-fuel tank wiring connection issue began as increasingly hard to start until it would no longer start: viewtopic.php?f=55&t=46425

Fuel pump is working using the GRN/F/P jumper wire test and is getting to the injectors because it does fire up eventually. It takes maybe 5 to 10 tries with the ignition key before the car starts.

gslender · Postby **gslender** » Sat Oct 04, 2014 9:31 am

There is a fairly common issue with either failing fuel pump or wiring to it in NBs where it can have this symptom - it runs fine, but hard to start... eventually it won't start and the pump and/or wires within the tank to the pump fail. If the pump isn't providing enough initial fuel pressure then the injectors will not be injecting the correct fuel at start and it will be difficult to start until pressure builds up.

Try this - turn ignition on/off with a 5 sec wait between on and off. Do that about 5 times and then try to start. If it starts correctly then it is very likely the fuel pump. If not, then move on and check the fuel pump off as being ok.

G

93_Clubman · Postby **93_Clubman** » Sat Oct 04, 2014 11:14 am

myredmx5 wrote:Fuel pump is working using the GRN/F/P jumper wire test and is getting to the injectors because it does fire up eventually. It takes maybe 5 to 10 tries with the ignition key before the car starts.

The fuel pump in the above example was fine & is still going strong. The problem was with the electrical connector block at the top of the tank (ie at the top of the removable guage/pump assembly), but only visible on the inside.

Initially identified it by testing the top two connectors with a multimeter for continuity from outside the tank - some resistance found, hence the impact on normal starting.

manga_blue · Postby **manga_blue** » Sat Oct 04, 2014 5:40 pm

myredmx5 wrote:
manga_blue wrote:Run some jumper leads across from a car with a known good battery.
I used a battery which started my other MX

The coilpacks in an NA8 draw a fair bit of power. I've often had issues in my NA8 when the battery is getting a bit weak that there's enough power there to turn the motor OK but not really enough for the coilpacks to fire well. You really need to test with a bigger or boosted battery.

Have you tried taking a plug out and turning the motor to make sure you've got a solid spark? Ignition problems are much more common than fuel ones with NA8s.