Hard starting 1990

[Badwolf]

This has probably been covered elsewhere, but here's the problem:

I'm working with my friend who also has a 1990 (luxury model with power everything) 3.0L with a 5 speed - 250K miles. It wasn't running, but we diagnosed the problem being the Mass Air Flow sensor, and replaced it. Now, once we get started, it runs great, but getting it started is a real nightmare.

It doesn't seem to want to catch, but will start up if you nurse the throttle (we shouldn't have to do this on an FI engine). I had heard that some engines have some sort of "starting" injectors, separate fuel lines or something along those lines, but damned if I can remember where I heard it. Anyway, could this be something along those lines? What are we overlooking here? Any tips would be greatly appreciated.

Thanks.

 

[blue95sr5]

is the MIL on? i see some stuff in the Toyota service manual about a cold start injector, maybe thats what you are talking about?

 

[bigbsvo]

Cold Start Injector

is the MIL on? i see some stuff in the Toyota service manual about a cold start injector, maybe thats what you are talking about?

Yes, I agree that the cold start injector could cause this. But you need to tell us more info, what lead you to replace the mass air meter? Was it just a guess or did you have codes stored? If you had codes what were they?
Do you have a check engine light on now?

Older Toyota's are a pain in the butt to get a fuel pressure reading because they don't have a schrader valve to make hooking up a gauge easier to do. And the banjo bolt on the rail is hard to get to because of the plenum.

Tell us more so we can try and help resolve this issue.

Bryan

 

[bigbsvo]

Cold Start Injector

Here is a picture of the passenger side of the upper plenum.
Right below the Y on the Toyota imprint on the intake is where the injector is, you can see a wire harness plugged into it and the banjo bolt that holds the fuel line to the injector, its to the left of the egr pipe.

 

[Badwolf]

The mass air flow sensor (the unit right above the air filter housing) was diagnosed with codes (don't know what they were, but Brandon said there were two codes, both of which pointed to the Mass Air Flow Sensor). In an attempt to get his rig going, we swapped the MAF from my 1990 and she started - hard - but she started. Then she settled in nicely. Since we figured this was the problem, we decided to "open" the sealed section on top of his black module - there were two fried soldered links on some of the "springy" leads which attach to the rotating plate. We re-soldered those, and sealed the black module back up with RTV (probably not professional, but it got the job done). We put his back on and it worked! The two blown contacts were inhibiting the spark - we used a test lead light to determine there was no spark getting through. We were so stoked. We did the basic "air, fuel, spark" determination, and figured it was the spark in this case. We fixed the module and she runs well.

The next thing to handle is the cold start - I'm no mechanic - Brandon kind of knows what he's doing, but he's more versed in air-cooled VW than Toyota. I had heard about a cold-start injector (that seems to be the term) but have no idea where it is. Brandon is a few steps ahead, and has already been looking for one on eBay and at the local parts store.

The thing is now - his insurance company is totaling his rig due to hail damage - he has to get a "type 3" inspection by the State of Arizona, so that the now "restored salvage title" vehicle can be used on the road. Seems like a lot of bureaucracy, but I guess they want SAFETY FIRST!

He's getting that done today. Then he needs to get his settlement, keep the car, get it running right and sell it because now (since we've gotten and clean smooth running engine) he is starting to hear the faintest indications of an engine knock and doesn't want to deal with that - so It's Sayonara to the 1990.

But that leaves us with the cold start issue - we really need to get that resolved so he can easily sell the car.

I think we're heading in the right direction, so I'll keep you posted, and thanks for the help.

 

[Badwolf]

To continue with the questions -

- The check engine light is NOT on (I don't think it ever was - so maybe there's a problem there, too).
- I'm not sure what the "MIL" is.

Hell - I don't know what a lot of the terms thrown around here mean (had to look up deckplate mod, for example), so I just have to ask.

Thanks again.

 

[blue95sr5]

the MIL is the malfunction indicator light, it just means the check engine light.