3.2 won't start

john hejmanowsk · 08-31-2003, 01:52 PM

Need some help!

Just did a 2.7 to 3.2 conversion, put a 20K mile '85 motor into my '77. Everything went great until I tried to start it up. Here's what I know:
1. engine cranks over easy, just won't start and really doesn't want to.
2. have a good blue spark
3. have gas - fuel pump works, gas at the fuel rail. Haven't measured the pressure, but the test port fills up a jar real quick.
4. when I put some gas into the throttle body (at the intake air boot, after the air flow sensor) the car starts up easy, but dies out when the gas is gone.
5. cylinder head temp sensor is probably original. measured 1.8 ohm - the book says should be 2.2 to 2.8 ohm but 1.4 is the low end.
6. have 12v at the injector solenoid (measured just one)
7. new dme relay, old dme. the relay checks out ok with power to each of the terminals. don't know if the dme is good but it looks ok, don't know if it is from the motor or from a different car. model number is 911.618.111.05
8. ground connection at intake runner is good.
9. gapped the speed sensor to .8mm
10. air flow sensor volts and ohms checked out ok.

Any ideas?

Thanks. John H.

sleepdoc · 08-31-2003, 04:07 PM

Hi John,

I have an 86 3.2 in my 914. Since you have spark visually and the car runs with fuel tossed in the manifold it certainly sounds as if the Motronic brain is providing reasonable ignition timing. In order for that to happen the brain has to be recieving power through the dme relay. OK The dme relay is a two part relay the second half being the fuel pump power. If while cranking the fuel pump is running the dme realy is basically ok and the brain is telling the dme relay to turn on the pump.For the brain to tell the dme relay to turn the pump on it must be recieving the required inputs ie speed sensor.

So it sounds as if the motronic brain is basically working controlling the ignition.

You mentioned that the fuel pump runs and there is pressure in the fuel rail. When setup as the motronic was designed the fuel pump should not start running until the speed sensor has convinced the brain that the crank is turning. If this is the case and you have pressure in the fuel rail while cranking than it seem your problem has to be at the injectors.

Since this is a low miles engine it doesn't seem likely all the injectors are bad. So I would look over the injector harness connections carefully. You say there is 12v at the injectors, are they opening? listen at the injector with a stethescope for the clicking. It sounds as if they injectors are not opening to me.

best Mark

BGCarrera32 · 08-31-2003, 07:17 PM

Quote:

Haven't measured the pressure

Do that next...if it starts sputtering when you dump fuel in through the intake boot then its either injectors or pump pressure...

ruf-porsche · ruf-porsche's Garage

Check the flywheel sensors for voltage

john hejmanowsk · 09-04-2003, 05:09 PM

Just wanted to say thanks to all for the ideas.

Checked the injectors with a noid light. They were getting signals from the dme.

Dhecked the fuel pressure. The pressures were 3 to 5 psi high so I am replacing the pressure regulator.

I also pulled the injectors and found what I think is the problem. There is major crystalization / crud / granuals in the injectors and lines. This motor sat for three years, the gas must have crystalized into crud. The injectors are probably blocked. I'll get them cleaned tomorrow.

Question: how to clean the fuel lines after the filter? There must be similar crud everywhere and I don't want the injectors to plug up again.

Thanks again for the help.

scottb · 09-04-2003, 05:34 PM

Once you get it going, I'd run some Techron thru it for 500 miles or so, and then change the oil again.

IROC · IROC's Garage

I'm fighting a similar 3.2 starting problem, but you're in better shape than me because you actually have spark.... If you're getting spark, then the speed/reference sensors are functioning (because it won't spark without the DME signalling the coil and the DME needs those signals from the speed/reference sensors to fire the coil) and if you wired your fuel pump though the DME relay (you don't *have* to do it that way on a swap) and you're getting fuel flow, then things seem to be OK in Motronic-ville.

I think you've got clogged injectors. They're probably stuck from sitting so long. A friend of mine's 3.2 sat idle for two years and he had similar fuel injector problems when he tried to get it running again.

I'd work on getting the injectors clean enough to allow the thing to run and then run a couple of tanks of Techron though it.

Mike

Jim Smolka · 09-05-2003, 04:43 AM

There is also a FI cleaner called BK 40, about $15 from Ford dealer.

old_skul · 09-05-2003, 05:31 AM

How does one clean injectors? I think I might have one that's partially clogged. Already ran two bottles of Techron through the car. (And no, I didn't change my oil afterwards. Neener.)

john hejmanowsk · 09-05-2003, 06:28 AM

To clean the injectors I have pulled them out and given to a local outfit "Midwest Fuel Injection Service Corp" to ultrasonically clean. I tracked these guys down thru the local better tuneup guys.

stlrj · 07:58 AM

Cleaning injectors is easy. The hard part is taking them off the rail. As soon as I get mine off I usually squirt the tips and inside with Gumout Carb Cleaner, seal them in a ziplock overnight, by the next day they're good as new.

Careful not to leave them in the ziplock more than a couple of nights because the "O" rings tend to swell up, making them difficult to reinstall on the rail.

Cheers,

Joe