I've got a 1989 Formula W/ TPI. I let the car set up for about 6 years. I'm getting it back on the road again. I was working on the steering column before I stopped messing with it. "tightening it back up" I bought a house and this car went on the back burner. I don't remember why I had put a new ignition is it. I think my ex-girlfriend took the key or something. Anyway, now I'm learning all about the VATS. I've changed the fuel tank and pump. "it was nasty" after all those years of sitting. Tried to start it and nothing. I've got fuel to the rail, fire and compression. So after some research. I found out my car has VATS. I changed the chip to a HYPERTECH thinking it would by-pass it. Nope! I bought plans and made a VATS defeater. It check out with the proper output voltage. Still no injector fire. Before I spend anymore money. I ask. Is it probably the ECM itself that's bad and causing the injectors not to fire? I've looked at all the wiring. None of the wires or plastic sheath has chew marks on them from little critters. Any thoughts? Thanks!

 

Check the resistance of the injectors. They need to be above 12 ohms. The OEM Multec injectors fail by having the solenoid coil shorting out. Once the total resistance gets low enough the ECM can't fire the injectors.

All eight get lost as the ECM only has a single injector driver in it.

RBob.

 

Thanks. I'll check it when I get off of work.

 

I checked all (8) injectors. All read 17 ohms except one. It was 22 ohms. So now do I assume it's the ECM?

 

I think your injectors are clogged.

Pick up a noid light first though, and see if they are getting pulsed.

 

I have. No fire. "Or Pulse" It's one of the first things I did. Any other suggestions? I'm all ears.

 

Do you have voltage on the injectors? And just no pulse?

 

Additional check, the ECM needs to see distributor reference pulses (DRPs) in order to fire the injectors. To check if the ECM is getting DRPs do this:

Key-on, engine-off, note that the fuel pump runs for 2 seconds and shuts off.

Once it shuts off give the key a short twist to crank the engine briefly, then leave the key in the on position.

The fuel pump should again run for 2 seconds then stop. Can repeat this test as often as desired. If the ECM gets a DRP it will fire up the fuel pump, which then times out after 2 seconds and the ECM will shut the pump off.

If the pump doesn't run at each short crank, then it most likely isn't getting any DRPs.

It may also be that the ECM is getting DRPs, but it is bad.

RBob.

 

Yes. No ground pulse.

 

Thanks. I'll double check when I get home. I was away from a computer all day yesterday. So I'm just now getting this today. Going off of memory. The pump runs and shuts off after 2 seconds. But it won't even come back on until the ignition is off for abut 20 seconds. I know this because I was trying to make sure the line was primed after installing the new tank and pump. I used an external inline high performance pump capable of over 100psig. But, I haven't tried doing exactly what you just laid out for me to try. I'll let you know how it turns out. Thanks again.

 

As far as the DRP signal goes. It's working just like you said. The pump even comes back on when you try and crank it for about 10 seconds and runs for two seconds. While I've got your ear. Do you know if the ECM that Oreillys Auto Parts sells needs to be programmed or not? The guy at my local store couldn't tell me. I think the one I have is aftermarket. It's made by Blue Streak Electronics out of Canada. I can't make out any part numbers on the tag. It's got boxes on the tag with no script.

 

You need to remove the MEMCAL from your current ECM and put it in the 'new' ECM. Note that the ECMs are all made by GM, Blue Streak is just a reseller.

If you can dig up an ECM to try I would do that first. Doesn't make sense to swap a possibly good ECM for a re-man of questionable history.

I'd again look at VATs being an issue. As this is exactly what is does, disable the injectors.

RBob.

 

The ECM was $90.00 with tax at Oreillys with core. If this doesn't work. Then I'll have an issue with the guy that sold me the plans for the VATS Defeater. The plans said if it was putting out 4.3VDC It was working correctly. " I think it was 4.3VDC" Whatever it was supposed to be on the spec. is exactly what it was when I installed it. I'll let you know how it turns out. Thanks for all the help. I have another question. I'm getting this engine running so I have proof that it runs. So I can Sell this engine. I have an L98 out of a 1990 C4 Vette I'm going to install and get rid of the 305ci. In 1990 The Vette engines went from MAF to MAP. The ECM is a completely different set-up. I bought the Vette engine. Wiring harness, ECM and all. So basically the engine is still wired. My Question's are. Should I just use the MAF system and wiring harness that's in the car now or install the MAP system? Or is it even reasonably possible to do so? Will my ECM / MEMCAL Combo for the 305 work for the 350? I've noticed the MEMCAL part numbers are different. But is that just for marketing or will it actually make a difference? Sorry for all the questions. But you seem to really have your ***! together where these engines are concerned. Thanks.

 

Great News! The injectors are now firing. Bad News! It still isn't even trying to start. I'm guessing now 8Mike9 is correct too. Like I said before. I'm more low tech "carb" mechanic. Any way to unclog the injectors? Or is it lights out?

 

You can try soaking them in carb cleaner...Sofa recommends Laquer thinner, which I just used to clear some plugged emulsion tube...but insure where the clog is...i/e if the pintle needs to be open, I don't know how that would work.

For mine...I just opted for the rebuilt Bosch injectors from Southbay....less than 175 to me and a 3 year guarantee...seemed very worthwhile...and yes, I am a tightwad

 

Double post

 

I'm Captain Tightwad. LOL I'm not going to use this engine. I just wanted to get it running again so I could sell it easier and for more $$$$$ It was running when I stopped playing with it. I need my A** kicked for letting it sit for so long. I bought and kept this car because I wanted one so bad in High School. Yes I was in HS in the 80's. Crap I'm getting old! I will get it going again. What do you think about the Vette MAP engine I have verses the MAF that's in it now? Should I keep the MAF set-up?