snardos

I have a 1992 Z-28. I recently bought a used 305. I have good spark, inector pulse, 45 psi fuel pressure. I have checked to make sure the distributor isn't off about 4 times now. I have checked the firing order about 6 times. It seems like not enough fuel is getting into the cylinders. I already changed the injectors to my old ones which I know are good because the motor ran before. The motor is out of an 89 but I'm using my original plenum with map sensor and all that so the mass air difference shouldn't be the problem. If anyone has any ideas they would be greatly appreciated.

CreepingDeath94

iTrader: (4)

Do you have any communication with the computer? I had a similar issue on my car where the computer had logic, but it was off somehow...still sorting it out actually. Basically, the computer read coolant temp at 100 degrees all the time, O2 numbers arent right with whats actually going on. In short, it affected the starting and running of the car. It would finally start but ran like crap and too rich. Try getting a scan tool on there and see what the computer is reading from the sensors with the key on.

high c

how about fuel filter or fuel pump, what about the fpr? is it from the new motor or the old?

Mcdamit

check your compression, and spray some starting fluid in the manifold.

snardos

I wish i had a scan tool...Ill have to find some way to get a hold of one because I think thats the next step. I checked the compression and it was around 140....but that was just in number one since I had the spark plug out anyways, and its the easiest one. I tried starting fluid and that seemed to help a little bit. It seems like it only wants to run on three cylinders max....mostly just on two, but i have spark on all wires and I have all new plugs. I used the fpr from the new motor but its gotta be good because even when cranking it still has around 47 psi. I know the injectors are all good because I disconnected the fuel pump relay and had one injector plugged in at a time when cranking, and each one made the fuel pressure go down slightly. So theyre working. It really seems like a timing problem but i cant figure it out.

Thanks for the advice so far but I'm still stumped. I almost bought a new ecm today but I decided it wasn't worth 150 bucks to try it out.

CreepingDeath94

iTrader: (4)

I wouldnt just slap a new ECM in if youre not sure. You have a timing light and are disconnecting the wire to set your base timign right? Also, what are you setting the timing to?

iroczracer07

iTrader: (2)

Don't bother buying a scan tool. If you have a car manual and a paperclip, you have all you need. Bend the paperclip into a u-shape and insert it into the a and b terminals on your Assembly Line Diagnostic Link (ALDL) under the drivers side of the dash, near where your right knee would be. Then turn the key and presto! The service endinge soon light will blink once, followed by two more blinks. It'll do that three times before spitting out any other codes it has. Right the codes down and look them up in your manual. Then post your findings again, and somebody should be able to help you figure it out.

snardos

Well normally what i have done when installing a new engine is to make sure number one piston is at tdc on the compression stroke and then put the distributor in so it is pointing to number one on the cap and then set the timing after it is running. Is there something else I have to do with this car.

snardos

about the scan tool issue, I already checked for codes using a wire and there were no codes other than twelve. I would just like one to see the live data.

CreepingDeath94

iTrader: (4)

Agreed, I don't think a scan tool is a waste if you know what youre looking at. The ALDL will only give you codes. I like to be able to see what my sensors are reading, etc. so I can do everything in my power to figure it out or at the very least have the info. to post here and make finding a solution as easy as possible. However, it isn't a very practical tool to have if you only use it on one car. So I could see the argument for both views there I guess. Depends on how much youre willing to spend...money could buy something other than a tool...

snardos

Well I guess noone else has any ideas and I am totally stumped as to why it wont run. I checked the compression today and they are all all between 130 and 150. I also rechecked the distributor and then tried it one tooth over and it didn't help. I'm sure I had it right before anyways. I guess I'll try bringing it over to a garage as much as i hate to do that. Hopefully they don't charge me too much to figure out what I already know.

snardos

I dont know what happened but I was just messin around with the distributor and crankin the thing and all of a sudden it just started and now it starts every time. It seems like it was flooded or something. I dont know, but it works so I dont really care as long as it keeps working. Thanks for helping anyways.