1G The injectors are not pulsing.

[dsmmatt28]

Ok Ive searched and I've tried. The injectors are not pulsing. This is what I have done on this rebuild. I swaped coil packs and transistors from 90 to 93 and gauge cluster. Using this vfaq converting a 1990 to a 1991-1994 ecu system. I check my wiring and its correct. So here is what I know. If i pour a little gas in the nipple on the intake that the pcv line goes to the car fires right up!. So we are not getting fuel for sure. The car sat for a few months while I was doing a rebuild. I was running e85 so I thought maybe that went bad so I drained the tank put in 93. Im getting FP to the fuel rail. This is what I have done. Swaped ecu with a stocker and put in 450cc, swaped cas, coil packs, resistors, injector resistor box, mfi relay, fuel pump relay, check all fuses check coolant temp sensor, checked all connections and plugs that plug into the fire wall. I checked the plugs and timing they are right. Remeber if I pour a little gas in the intake manifold the car fires right up and will idle with no mis untill I quite pouring then it will die. If you have had this problem and resolved it let me know or might have an idea what it is.

 

[mikelv]

Did you switch the pump out, forget to plug it in?

 

[dsmmatt28]

The fuel rail is getting fp i can verifty this looking at the fp gauge. plus i can hear it.

 

[mikelv]

It has to be electrical then, it has to be man from what you said.
You got spark, and you got pressure, just the ECU is not telling the injector to pulse. You can try swapping it again, or re-check your connections.

Try reversing your steps in the swap one by one until you correct the problem.

It seems like you did an ass load of things so it can be hard to narrow down.

Unless you got back luck and got bad injectors themselves.

I know it sucks, but you're probably going to have to get the car back to the way you started and do one thing at a time until it stops working, and you can narrow it down to that system.

I'm going to forward this problem to my buddy Brad. I'll give him a call later, he's pretty much seen it all. I'm curious, I'll let you know what he says.


BrooksTuned,BrooksTuning,AEM, Brad Brooks, Trigger discs,4g63, 1000hp,EMS,Tuning,Best

 

[dsmmatt28]

yeah man this one has got me stumped like i said i put a stock ecu and 450cc injectors just to try and get the car to fire but no luck. im going to grab another cas this will be number 3 maybe i have two bad ones. So i work at aFord delearship and Im a mechanic I have always fixed my own car this is my firtst help thread. Ive done everything that i can think of. I know the cas is what supplys the pulse to the injectors or to the ecu and the ecu pulses the injectors. i dont knoe ive been trying for 3 days now before ive posted this up.​

 

[mikelv]

I don't think it's the CAS, but the CAS could be way out. Usually that's a timing problem though.
I've had a car run like shit, and not run at all from the CAS being way way out.

Did it not run with the old ECU?

Looks like you got a long weekend of DSM headache syndrom ahead of you. Also know as (DHS).

 

[dsmmatt28]

I dont think its the cas either otherwise the car wouldnt fire up whe i pour gas into the intake. The old ecu was brand new eprom with a keydiver chip and yes the car ran fine. I spun a rod bearing and did a rebuild. I put the new chip in there and the car wont fire. I put a stock ecu in and 450cc injectors and the car will still not fire.

 

[mikelv]

I dont think its the cas either otherwise the car wouldnt fire up whe i pour gas into the intake. The old ecu was brand new eprom with a keydiver chip and yes the car ran fine. I spun a rod bearing and did a rebuild. I put the new chip in there and the car wont fire. I put a stock ecu in and 450cc injectors and the car will still not fire.

Ok, well the car hasn't ran since the rebuild, but it WILL fire when you do the little gas trick. And run fine? Did you have someone help you, so you could throw a timing light on it after it was running? Try that and see what you get.

So it does have spark, just no fuel. When you turn the key the starter turns over fine, just doesn't start right?

Do you smell any of the fuel on the plugs after just trying to start it normally?

Did you actually arc the plugs to make sure every wire is sparking? Make sure you use a good plug and wire on each cyl to ensure you're good too.

Make sure you can eliminate without a doubt that it's not a spark issue, or a timing issue.

 

[dsmmatt28]

I check spark is arcing. The car is not geting fuel. Why cause ????

 

[bento]

Have you tested the injector pack resistor on the firewall?

 

[dsmmatt28]

Yes I replaced it with one that came off a running car. Ive done everything and checked every thing that I can think of that should make a dsm run. I got a noid test kit today going to check each plug and take the cas out spin it by hand witht the key in the run position and see if the noid flashes. Im going to run a continnuity test from the injector plug all the way back to the ecu aswell. If this checks out to be good, then Im really going to stumped.

 

[soulweaver]

I would say your ecu. i had the same problem as you and my ecu was the problem. I didn't do all them mods but obviously it's an electrical problem. What i would do is check the ecu again. and take ## time with it.

 

[dsmmatt28]

I put. A stock ecu that I know wks in the car and took out my eprom ecu. The car still will not fire. I was researcing the cas and found out their is two circuts in there one for spark and one for pulsing the injectors. Maybe I have two bad early 90 cas, I'm going over to my friends when I get off wk and grabing his off his car that I know wks

 

[dsmmatt28]

Resolved 2 bad cas!!!!!

 

[We're on Boost]

Hey Matt, are you going to post your dyno results in here somewhere after tomorrow?

Gary