Need help after changing fuel filter

[Superfly9c1]

My Caprice was running rough, particularly after adding fuel treated with Stabil, so I changed the fuel filter with a K&N filter. Now I cannot get the engine to do anything but turn over. A little background on the car: I just bought it from a small mechanic shop whose owner told me the engine had been changed with another LT1 around 2 years ago and the car has been sitting for a while. I was able to drive it even though it was running rough until I added the 3 gallons of gas with 1ml of Stabil added. Any ideas?

[donfrye]

Can you hear the fuel pump priming?

I left my Camaro sitting 2 years, started it, drove and the fuel pump went next time I tried to take off.

[Superfly9c1]

Yes, I was wondering if I needed to click the ignition over to let the fuel pump build pressure. But yes I can hear the fuel pump cut on when I turn the motor over

[Superfly9c1]

I'm going to try adding more gas tomorrow along with some Seafoam. There was plenty of fuel in the line when I changed the fuel filter

[donfrye]

Have you checked for fuel pressure up front since the change?

[Superfly9c1]

Not yet, I have to find a fuel pressure gauge that I can afford to borrow. All of the local parts stores are asking too much of a deposit

[popo8]

Def start by checking fuel pressure at the rail and report back.

LTXtech.com IS my drug...
OWNER/ADMIN

[Superfly9c1]

Something obvious just dawned on me. My garage bay that the Caprice is in has one side open and I left the hood open while it was raining pretty hard. So it is possible the Optispark might have got a little wet.

[popo8]

"Little wet" isnt gonna do it. Start with fo and lets work from there.

LTXtech.com IS my drug...
OWNER/ADMIN

[Superfly9c1]

Today I'm going to remove the new K&N fuel filter I just put on to make sure I didn't do anything idiotic like put it on backwards

[donfrye]

You can check to see if you at least have "some" fuel pressure by depressing the relief on the fuel rail up front. That will give you a slight indication of movement.

I think this FP tester works and it's 20 bucks.

http://m.harborfreight.com/fuel-injection-pump-tester-92699.html?utm_referrer=direct%2Fnot%20provided

[Superfly9c1]

Today I tried it again and it started on the 2nd try and idled a lot better than before. I guess it needed the fuel filter and it took it a while to build fuel pressure. The check engine light is on, but I think that may be from the pcm after the engine swap.

[popo8]

Today I tried it again and it started on the 2nd try and idled a lot better than before. I guess it needed the fuel filter and it took it a while to build fuel pressure. The check engine light is on, but I think that may be from the pcm after the engine swap.
Have u checked the fuel pressure at the rail yet?

LTXtech.com IS my drug...
OWNER/ADMIN

[donfrye]

Not sure what the hesitation is in checking for pressure. Tools are cheap and a "must own" in older EFI and engine-swapped cars IMO.

Issue is probably unresolved based in the info you've shared.

[Superfly9c1]

I plan on buying a fuel pressure tester, but it is one of the things on my list that I haven't gotten yet. This is my first project car and I'm not very mechanically inclined. It is running good now besides the check engine light and the low oil light being on. It shows full of oil in the dips tick and also the odometer keeps changing as it runs, from 100,000 up to 495,000. I am going to check with PCM PERFORMANCE to see how much it would cost to have my PCM reprogrammed and if that will straighten out the bugs. I have no idea if the PCM was changed with the motor, so that might be part of my problems

[Shilaeli Hugger]

Taken it to autozone or advance? Better to get light checked instead of programmin. Plus its free. Oil light mite be the plug dusconnected in pan

[Superfly9c1]

I don't have the car registered and it's a lowrider with the hydraulics not working, so driving it to the local parts store isn't an option. What scanner can I buy to use at home to check the check engine light codes? I know it's a Obd 1,so do I need to get one that flashes the check engine light to tell you the code,or do the adapters work that convert a GM 12 pin plug to a 16pin Obd 2 reader?

[Injuneer]

You can't flash the codes by shorting the pins, 94 and up. 93 was the last year. You need a real OBD-1 scanner, or combination OBD-1/OBD-2 scanner, not a $30 "paper clip in a box". And using a 12->16-pin adapter will not allow an OBD-2 (only) scanner to work on OBD1. Scan9495 should be able to work. We can check w/ GaryDoug to verify.

[Shilaeli Hugger]

Is it 95 or 96? U mite be able to do a loan a tool from em but im not sure on scanner. 94 n 95 were obd1 but obd2 connector so makes it kinda crappy. Cant use the old paper clip trick to count the flashes. The parts store should have some kinda cheapy scanner available but from i remember dealin with my 94 they said scanner wont work... of course these were same people that argued with me that i didnt have a 4.3 v8.

Go pick up a scanner n give it a shot. Try do the basic stuff first. Eyeball everything. Make sure plugged in. Double check that m all fluids. If u have to crawl under it and check plug routing. That bit me . Make sure no wires are groundin out.

Does it act up cold or after its run for min or 2?

Definitely woulda bought tooks to get it runnin right before moddin suspension :p

[GaryDoug]

... Scan9495 should be able to work. We can check w/ @GaryDoug (http://ltxtech.com/forums/member.php?u=6461) to verify.

It should work for a Caprice, a B-body/platform car. I have never tried it myself but have heard from some Caprice owners that it works well.

I just tried my Actron CP9185 on my LT1 pcm setup by using the 94 Caprice LT1 engine setting and it appeared to work fine. It sells for about $71 on Amazon right now, but for a 94 you will also need the CP9127 OBD1 cable set (with cigar lighter cable) for about $35 more.
https://www.amazon.com/Actron-CP9185-AutoScanner-Diagnostic-Scanner/dp/B000T8UG52/ref=cm_cr_arp_d_product_top?ie=UTF8
Some things listed in the ad for features don't work for the OBD1 cars, like there is no graphing and very minimal logging.

It is possible to use this scanner on your car without the CP9127 cable set, but it would require connecting two wires from the 16 pin connector on the scanner cable to the DLC in your car. And the scanner would need a 12v cigar lighter cable with a 5.5/2.5mm pin and 12v in the center.
http://www.ebay.com/itm/12V-12-Volt-DC-2-5mm-5-5mm-Car-Cigarette-Lighter-Power-Cable-Plug-Adapter-USA-/131426386974

[Superfly9c1]

The car is a 94 with a 12pin plug. I have to try to find out what year the motor is though. The hydraulics were installed, very poorly, by the second owner who was the guy I bought it from's brother-in-law. I was told that the motor was bought from the same sheriff's department as the car. It has been a headache because the guy I bought it from doesn't speak much English and I only know a little Spanish. He told me that he changed the engine due to a rattling sound that ended up being an exhaust leak. The engine cranks and runs good since I changed the fuel filter but the check engine light comes on immediately and sometimes the low oil level light. The oil pressure gauge stays on high anytime it is running and the odometer keeps changing from odd numbers. I am going to go to Auto zone when I get paid Wednesday to get a OBD1reader

[GaryDoug]

None of the OBD1-capable scanners available at Autozone will work for a 94 or 95 LT1 except the CP9185 and CP9190 kit (CP9185 with more cables). Autozone sells the CP9185 for $250. Amazon has the identical same one for $71. Your choice. None of the Innova scanners will work and neither will any others that are under $50.

[Superfly9c1]

With the CP9185 I will need the 16 pin to 12 pin adapter cord, right? Thanks for the advise, I am sure yall have saved me time and $! Hopefully the CP9185 will help me figure out what is going on. Thanks again!

[GaryDoug]

With the CP9185 I will need the 16 pin to 12 pin adapter cord, right?

No, not unless it is the CP9127. Do not trust anything else to work. I know there are a lot of those 16pin-to-12pin adapters available on the web, but they will not work for your car. The CP9127 is a kit of two cables, one goes from the CP9185 scanner cable to the 12 pin car connector (not 16-to-12) and the other is the cigar lighter 12v supply cord that is needed because the 94 does not have the 12v at the car connector.

[Injuneer]

As Gary points out.... the Actron CP9127 OBD1 Cable Set is the 12-pin cable for your car. No other adapter needed.

[Superfly9c1]

I ordered the CP9185 and the CP9127 OBD 1 adapter, so hopefully in about a week I can find out what is going on. Thanks

[Superfly9c1]

I got the CP9185, now the problem is that my cigarette plug in doesn't work. Will I get an accurate reading if I plug into my 12 pin on my Caprice and plug the 12v into another car?

[GaryDoug]

That should work. But have you checked for a blown Cigar/Horn fuse yet? Make sure neither car is connected to a battery charger or anything line powered.

[Superfly9c1]

I'm getting codes for 043 and 023,low manifold temp and escape problem. Does that mean the Optispark?

[Superfly9c1]

After checking in my Haynes Repair Manual, it says code 43 is the PCM not receiving a knock sensor response. Could it be that the PCM needs reprogrammed?

[GaryDoug]

Use the shbox.com site for your codes. http://shbox.com/1/Dtcs.htm
Or use the 94 F-car factory service manual.

DTC 43 is : Knock Sensor (KS) circuit
DTC 23 is : Intake Air Temperature (IAT) sensor circuit (signal voltage high, low temperature indicated)

Neither is likely anything to do with the pcm. Check the connectors of both. If ok, replace the sensors.

[Superfly9c1]

After checking in my Haynes Repair Manual, it says code 43 is the PCM not receiving a knock sensor response. Could it be that the PCM needs reprogrammed?

[Injuneer]

DTC 43 means the voltage on the single-wire knock sensor circuit is not within the specified range (0.78 - 4.10 volts). Should not affect the starting. When DTC 43 sets, the PCM retards timing based on engine operating conditions, but that's with the engine running.

Easy to check the circuit. Key on/engine off pull the harness connector of the knock sensor. Measure the voltage between the single conductor in the connector and the engine block. Should be 5 volts. Connector still off the sensor, measure the resistance between the pin on the sensor and the block. Should be about 3,500 - 4,500 ohms. Put the connector back on the sensor, check voltage between the wire and the block, should be in the range of 1.5 - 3.5 volts.

In general, it's better to use LT1-specific sites like Shoebox, rather than Haynes or Chilton.