dji1

I can do that. When I pull the check valve off, I will plug the line going to the intake.

94 Silverado 350 When I apply the brakes, the rpms drop. In park or neutral the drop is approx 150 rpms and in reverse or drive approx 250 rpms. When I release the brake, the rpms go back up to normal. I installed a new booster (rebuilt) last august 2025. Didn't have any problems until a couple of weeks ago. When I was working on the throttle body issues last month, I noticed some leaking around the booster vacuum line, so I replaced it. I have gone back and re-tightened the hose clamps and don't hear or see and leaks. I don't think the booster itself is leaking internally. The brake feels like normal and it stops ok. The pedal doesn't go to the floor, and I don't hear any hissing. When the truck is off, I still have pressure, so I guess the check valve is, ok? I do question the rubber check valve grommet. Maybe its leaking around it? The replacement hose was just a section of new hose. I plan to check it some more and test the check valve. When I rebuilt the throttle body, I did replace the idle air control valve with another one I had. It was almost new, so I don't think that is a problem. Any other ideas or test suggestions. Thanks

I was thinking about doing both. After I take the tbi apart I will clean and look things over. I am still undecided on redoing the fuel regulator. Normally I would just replace everything. Now I just want my truck back and running.

I hope so. I am surprised that the truck runs fairly decent with just 1 injector.

It looks like the injector is bad. I measured the resistance and it is less than .5 ohms. The good one is 15 ohms. I also found out that you can connect the injectors with either plug. Also, the individual injector connectors themselves are not polarity sensitive. So, I swapped the plugs and the passenger side would still not work. The driver side still worked. So, I can eliminate the ECM and wiring. I order a TBI gasket set and a new injector. Should be here in a day or 2. I think I may just remove the complete TBI and work on it off the vehicle. Thanks for all the help. I will let you know how it turns out.

I can't really check the working one. If I disconnect it the truck won't run. How do I check the ecm?

I started the truck and tested for the injector's ground pulse. I do get a dim light on the test light. Was the light supposed to flickering or stay on since the truck was running? I can use my voltmeter and see what the voltage is if that would help. Does this mean the injector has a problem? Is there a way to test an injector on the vehicle? Would measuring the resistance of an injector mean anything useful? Thanks

The passenger side injector is not working at all. It is getting 12 volts. I couldn't test to see if the ECM is sending a signal to the injector. No one around to help crank the truck today. I was going to buy a Noid light at AutoZone $5.99 but they don't stock it. They just advertise it online. I'm going to modify my test light and see if that will work. Didn't have a problem today seeing the injector (no) flow. The natural light was perfect. If the ecm is the problem, would it affect both injectors? Or if 1 injector is working then the other injector has a problem.

I am going to try the timing light suggestion. I purchased my timing light in the early 70's. It has a spring that you attach one end to the plug and the other end to the wire. It's not user for sure but it works so I have never upgraded. I also will try and set-up more lights so I can get a good look. The shadows under the carport were not good this afternoon. I can also move the truck to a better position if I need to. I will check the polarity of the connectors before I swap them. Thanks

It looks like the passenger side injector is not flowing much at idle. I think. It is hard for me to see for sure. I may just pull a plug on that side to see what it looks like. When I give it gas, I can see the flow on both ejectors. The driver side looks okay. Can I swap the connectors from 1 injector to the other side injector? There is a very small chance that when we soldered the new connectors on something went wrong. I took a video with the truck running. tbi.mov

Yea that is the 2 reasons I haven't bought one before. I am sure I would use it once and have no need for it again. The only reason I thought about it was that it was only about $20 and I have never tested fuel pressure before and I am not sure if 1 person could, do it? I bought a brake bleeder kit years ago that I forgot I had. Found it in the garage the other day. Brand new never used it. When I was checking it out to use all the nipple attachments broke in my hand. I may try the loner tool at the parts store. Never had in the past. I don't think the fuel pump is the problem this time. When I drive down the road the truck runs okay. I re-checked for vacuum leaks again last night and I don't hear any. I also checked the wiring to the o2. It looks excellent. I am going to re-check the injector patten in a few minutes to make sure. I didn't remove and clean the EGR valve last night. I replaced the gasket and cleaned it less than 10 years ago that is only less than 50k mile for me. I still may do it. Should I start a new thread for the idling problem? It is no longer a won't start issue. Thanks

I reset the kickdown cable back 1/4 turn. While I was driving around today, I finally got an error code 44 (lean exhaust) The truck was warmed up, and I was idling at a stop sign. I am going to re-check for vacuum leaks. I did replace the hose for the brake booster. I am going to check the wiring to the O2 sensor and remove and clean the EGR valve hopefully tonight. I have been thinking about buying a fuel tester at Harbor Freight just to eliminate pressure issues. Any comments? Thanks again.

No, the throttle body was not removed. Just replaced the electrical connectors. Ten years ago, when I replaced the tpi base gasket. I did adjust the kickdown cable then. I think someone told me on a 94 the kickdown cable was there but it did not control anything anymore. The sensors do all the tpi adjustments. I did notice that the kickdown cable was tight and had no slack in it like usual. Not sure why or if it even makes a difference on my 94? I did loosen it a 1/4 turn this morning.

I removed and cleaned the IAC. Disconnected the battery to reset. Same problem. I will drive it around tomorrow and see what happens. I didn't think there was too much carbon built up? The throttle top side plate is clean. When I was trying to figure out why it wouldn't fire, we sprayed quite a bit of throttle cleaner. Also, that is when we checked the injectors spray. All that seems fine. See attached photo's

The original problem was the injector wiring harness. OBD1, I will clean the IAC. I have had some issues with it over the years. Replaced the IAC and wiring 10 years ago.

When I start the truck cold the idle is about 800 rpms and the idle is smooth. When I put it in reverse or drive the idle drops to around 400 rpms. Do you think a bad throttle positioning sensor would cause this problem. I remember about 10 years ago I replaced the TPS because of an idling issue. If auto zone lives up to their lifetime warranty and I can find a store that has one I may just replace it. I am going to remove it and see what it looks like and check the connector. If that doesn't work, I will clean the idle air control valve. thanks

I was going to check the idle control valve when I pulled the spark plugs and clean them on Sunday. Most of them were black. When I am stopped at idle for a long time in drive, I get code 44 lean exhaust. It goes away when I am moving again.

I really didn't think the new air filter would do much. It was just time for a new one. I am not sure what you mean by throttle blade stops. I did adjust the throttle cable? Smoke color was black but no longer a problem. Sprayed a lot of throttle cleaner when trying to get the truck to start. I did find a vacuum leak. Hose to the brake booster it has been replace. thanks

My truck has been starting right up for over a week. Original starting problem fixed. Had a bit of an idle problem this week. When I was in reverse or drive (when stopped) the idle would drop down below 400rpm's sometime stalling. Disconnected both battery cables for an hour yesterday and now it's better. ECM has reset. Still a little low on the rpm's when in reverse and drive (when stopped) but it's better. Plan to get a new air filter. Maybe this will help?

One of the first things I did was to replace the ignition module. I did get it started at the end of last week. It smoked a lot, but it ran smooth. I had some help. Replaced the wiring connectors to the 2 injectors. Bare wires. Unfortunately, the battery went bad and I haven't had it running since I replaced the battery. Thanks

I did pull the coil wire from the coil. Since I am by myself, I had my phone set up and I took a video while I cranked the truck. I didn't see a spark. See attached video. I will try pulling the #1 wire and see if a get a spark. I will have to take a video. When I crank it, I can smell fuel in the tbi. I also tried adding some fuel down the tbi. When I replaced the fuel pump about 50,000 miles ago it would run for a bit when I did this. I do hear the pump engaging. If I had fuel pressure gauge I would have checked it. lifetime warranty on the pump. I am focusing on the spark now. Thank you spark.mov

I got my remote starter hooked up today and checked the timing. It is not 0 deg but not that far off. I can't read the scale, and I don't remember what I set it to when I replaced the distributor about 15,000 ago. I also re checked the fuses inside the truck. Not sure were the location of the under-hood fuse box? I know where the relays are for the fuel pump. Firewall passenger side. Thanks

I do have a test light and voltmeter. I have used both on this problem. The fuse box inside the truck I pulled most of the relevant fuses and used my meter. I also used it to check the coil. I hope I found all the fuses that maybe causing the problem. Tomorrow, I plan to re-check wiring and fuse to start off with. Then to the timing check. I used the test light to check voltage to the fuel pump under the hood. I haven't done anything on the truck today. I needed a break. I do plan to spend most of this weekend working on it. Thanks again for all the help.

I do have an old Haynes manual. I have been using it since the 90's. It is pretty good. I did download the Charmli manual (excellent) and I plan to look it over later today/tomorrow. The leads on my remote starter are not very long. I can't complain. It was only $2.00. I will jack the truck up and find a way to connect it to the starter solenoid. I thought I checked all the fuses under the hood and inside the truck. I will go back and make sure. Attached video spark.mov

I couldn't connect my remote starter to the solenoid. Couldn't get at it. I used my phone to video the un-plugged ignition wire from the coil. I didn't see any spark in the video. I not sure if this was a valid test. I just laid the un-plugged wire next to a metal backet. I also took the distributor cap off to see if the rotor would move when I turn the key on. It did. Does this tell me that the new ignition module is bad? Thanks