New guy 90 Jimmy first up cold start issues

[phrogs]

Ok First Im johnny I am a big corvette nut have had a 1990 ZR-1 in my garage for the last decade so thats what I know. I havent had a sweet k5 in a while and wanted another blazer so I ended up in a Jimmy.

I just picked up a 90 Jimmy, gas, 350, auto, stock heigth as far as I can tell. Just got this week and while it took me a while I got a pretty solid one that was my goal but she has some issues. Has 161K on the clock.

first thing is it has sat for around 3 years.

First issue one is really hard to start it cold but hey its in the 20-30s here now.
Takes about 5-8 starts to get it going, but once I get it wrmed up truck is fine runs fine and has ok power. The gas pedel is also pretty stiff unlike my other cars with a cable throttle its almost binding and I have to push on it.

Im guessing its something in the throttle body probably gummed up but I am going to change the fuel filter and see about cleaning the TB ony sugestions on that? Will throttle body cleaner be ok ? as you guys know these things.
Im also thinking the IAC valve may be gummed up or shot.
Any other sugestions appreciated.


I want to do a tune up as well where do you guys get your parts? Dealer still? Or advanced auto is really all I have local to me.

webistes that might be better?

Or parts I should steer clear of?
part recomendations?

Second issue it the steering it is pretty worn out.
Best place to get replacment parts?
Id like to do a lift in the future something that would have everything I need to include shocks? any that have all the front end compontents what about control arm bushings?

Thats all for right now.


johnny

 

[jeff in co]

I'd definitely clean the TBI unit up inside and out. Throttle body cleaner is fine. I think you can also clean the IAC valve as well. Probably has really old gas too. Run some injector cleaner along with some fresh fuel. If you can, either empty out the old stuff or go driving for awhile. Get rid of that old stuff.

I'd also get a new throttle cable. It should really help your gas pedal feel.

Do a tune up on it as well. Plugs, cap, rotor, fuel filter. If you can AC Delco but otherwise, not the end of the world. Good luck and congrats on the new truck!

 

[Jessie James]

I'll agree with the bad gas. Fill up the tank, put in some STP injector cleaner, and go driving for a while. A new fuel filter can't hurt, and it's relatively easy to get to (under the passenger side frame rail, about middle of the truck). A new air filter is also easy.

Check your heat riser tube. I needed a new heat riser tube (goes between the passenger side header and the underneath of the air intake housing inlet tube, about 1.5" diameter cardboard-like tube). It's cheap and easy and sends warm air to the engine to help it warm up quicker.

Once it warms up, here's what I did on my 1990 K5 to get it running better. I bought everything from Advance Auto locally, trying to get AC Delco parts when possible. However, considering it's freezing out there, you can probably wait on this.

1. Replaced both injectors. They are about $75/each. Take your time, do NOT forget the o-rings top and bottom of each injector (ask me about my engine fire...) and put in the new gasket for the assembly. You can also replace the fuel pressure regulator at the same time. This is all pretty easy.

2. New IAC, MAP (MAF?), EGR and PCV

3. Checked for vacuum leaks. This is a little time consuming, but basically follow the line off the back of the throttle body. You should have a few lines going to the cruise (if equipped), canister, and then the HVAC controls. Check each line by bending it - is it cracked or falls apart? Replace it.

4. Tune up - as mentioned.

 

[Adventurous 4x4]

I would just get a rebuild kit for the TBI and take it apart and clean it good and clean the injectors. While your at it replace the cable to fix the gas pedal. Make sure there are no extra springs pulling the throttle cable back toward the front. As far as tune up stuff, AC Delco stock plugs, MSD wires, a good cap and rotor, I prefer brass tips, and I would get a MSD coil. You can get it all from Summit Racing. Change the oil and filter. Also do a fuel filter and air filter. Run a tank of super through it along with some cleaner.

As far as your steering goes, what it worn out? There isn't much to the steering on them so just replace what you need. Find a good alignment shop if you're not comfortable working on the steering.

It has leaf springs up front unless it is a S10 Blazer. You can get a complete Tuff Country lift and it will have about everything you need. I would also get extended brake lines for a lift instead of relocating the stock stuff.

Your about 3 hours from me so if you need help and want to come to Carlisle let me know. There isn't much I haven't done on these K5's. I have a bunch of pics on facebook you can check out too.

 

[1-ton]

Your cold start circuit may not be working because the ECM has a bad input sensor. The temp sensor, o2 sensor, or idle control sensors could be bad.


These sensors tell the computer that the engine is cold, and to richen up the fuel mixture, in order to start quickly, until the engine temp sensor reaches a certain temp.

 

[phrogs]

Well I added a bottle of Injector cleaner and a full tank of fresh fuel she started up the second time still a little rough but once it warmed up it was good to go.

The only code I have is a 15 and if I read that corretly that has something to do with a coolant sensor have to read it again.

 

[lak2004]

another option to replacing the injectors would be to have them tested and cleaned by Witch Hunter . A little cheaper option.
And welcome to CK5! Plenty of info and nice to see you paid for the membership right away

 

[Russell]

As for your throttle cable -- Pull it off at the throttle body and twist it a couple of times / re-route it as much as you can then re-install it upside down as compared to how it was in the bracket before.

The problem with the pedal getting stiff is that the cable has worn a groove into it's sheath and that makes for a bunch more surface area causing friction against the cable inside.

As far as your poor operation, looks to me like there is something wrong with your coolant temperature sensor. Code 15 indicates an unrealistically cold coolant temperature reading after some pre-determined period of time with the engine running.

The temp sensor is a thermistor, which means that it's perceived resistance changes with temperature. High resistance indicates cold, lower resistance indicates warm. If your coolant temp sensor has a broken wire, or is unplugged, the ECM sees an open loop, aka infinite resistance, and thinks that it is extremely bloody cold outside. This causes your engine to run extremely rich as a cold engine requires much more fuel to run than a warm one does.

Check the temp sensor by unplugging it and probing it with a multi-meter set to detect resistance. Check the indicated resistance against the chart I've attached to make sure it is reading something similar to what it should be. If the temp sensor is good, you need to make sure that the black wire runs to a solid ground, and that the yellow wire makes it back to the ECM without any cuts, burns or frays.


177 ohms @ 212 deg. F. or 100 deg. C.
241 ohms @ 194 deg. F. or 90 deg. C.
332 ohms @ 176 deg. F. or 80 deg. C.
467 ohms @ 158 deg. F. or 70 deg. C.
667 ohms @ 140 deg. F. or 60 deg. C.
973 ohms @ 122 deg. F. or 50 deg. C.
1188 ohms @ 113 deg. F. or45 deg. C.
1459 ohms @ 104 deg. F. or 40 deg. C.
1802 ohms @ 95 deg. F. or 35 deg. C.
2238 ohms @ 86 deg. F. or 30 deg. C.
2796 ohms @ 77 deg. F. or 25 deg. C.
3520 ohms @ 68 deg. F. or 20 deg. C.
4450 ohms @ 59 deg. F. or 15 deg. C.
5670 ohms @ 50 deg. F. or 10 deg. C.
7280 ohms @ 41 deg. F. or 5 deg. C.
9420 ohms @ 32 deg. F. or 0 deg. C.
12300 ohms @ 23 deg. F. or -5 deg. C.
16180 ohms @ 14 deg. F. or -10 deg. C.
21450 ohms @ 5 deg. F. or -15 deg. C.
28680 ohms @ -4 deg. F. or -20 deg. C.
52700 ohms @ -22 deg. F. or -30 deg. C.
100700 ohms @ -40 deg. F. or - 40 deg. C.

 

[phrogs]

Do these injectors suffer from the ethonal in fuel? I know they injectors in my 90 Corvette go bad from the ethonal.

Ill have to check the coolant sensor.

 

[phrogs]

Wanted to update this since its been a while since I fixed it.

I had a bad temp sensor located in the intake manifold thats all it was.